The Down Range Forum
Member Section => Tactical Rifle & Carbine => Topic started by: twyacht on June 07, 2009, 06:33:16 AM
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Went to the range yesterday early before the storms came, outdoor facility to 100 yards.
Co-worker brought his AR-15 Colt Match Target HBAR with 20 inch barrel. 1in 7 twist Simple optics.
Getting to the question, Co-worker attached a bipod that clamps around the barrel.
Range officer stated the "barrel mounted access." effect "barrel harmonics" and ergo accuracy.
I understand the vibration thing, but came across frequency, and torque, barrel distortions, etc,...
http://www.rifle-accuracy.com/harmonics.ht
Can I get a "layman's definition on the frequency?" Will .223 from Wal-mart be more/less accurate than M193, or other rds due to different Hz? Is it true on barrel mounted accessories?
Does this only apply to rifles with longer barrels? Or different type i.e. bolt action,?
I didn't quite comprende the link, any help that I can process would be greatly appreciated.
Tom W.
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Link didn't work for me. But...yes it's the barrel's own resonance characteristics that determine a part of it's accuracy. A lot of people here know a lot more about it than I, but that's why I try different loads...even on the level of a 22LR. I've a Remington Matchmaster that will make one hole groups at 45 yards (my preferred zero point) with Remington Golden 22's...put a Winchester Dyna-Point in it and it is barely able to hit a 5 gallon bucket at the same distance. Same thing with my Finnbear Sporter in .270...it groups a cloverleaf at 100 yards with Federal Premium 130 grain bullets, loat it with anything else and nope...not nearly so good.
This is not a slight on any ammo. That Dyna-Point in 22 Mag shoots really well in a Marlin I have and the Remington...not so good in it.
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Sorry about the link, this one is identical.
http://www.varmintal.com/atune.htm
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That's all a little complicated for my simple mind. I say, if you find a load that works, stick with it.
http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=593560
There were also some mixed reviews with the de-resonator online, mostly positive though.
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That's all a little complicated for my simple mind. I say, if you find a load that works, stick with it.
http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=593560
There were also some mixed reviews with the de-resonator online, mostly positive though.
I can slip a rubber grommet over the barrel and shoot better? I don't know about all that. :-\
As someone who deals with frequency at work, we have different drives that control automated systems through frequency.
So, I am trying to get my hand around frequency on barrel vibrations, and if mounting a bipod via a barrel clamp has the potential to effect accuracy,
I don't shoot playing cards at 250yds, or have sniper training. On an AR platform, it may be irrelevant. How about a precision rifle?
Does it change anything? Inquiring minds wanted to know.
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I'm not really up on this stuff, but anything added on to the barrel will effect the propagation of vibration waves through the steel, and that will effect the accuracy in faster rates of fire, although it shouldn't if time is taken between shots to allow the vibration to run its course . Need to wait for an educated answer from some one like M25 .
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I'm not really up on this stuff, but anything added on to the barrel will effect the propagation of vibration waves through the steel, and that will effect the accuracy in faster rates of fire, although it shouldn't if time is taken between shots to allow the vibration to run its course . Need to wait for an educated answer from some one like M25 .
Are you SURE you have that right?!
;D
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Maybe "experienced" would be more appropriate ;D
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I'm leary about the de-resonator also.
I do know clamping a bipod to your barrel is a bad idea. Not sure about how it affects harmonics, but it does put stress on the barrel and can flex it, moving your point of impact. The warmer the barrel gets, the worse it will be. Same thing goes if you have your barrel resting against something when you shoot. It might not seem like a lot of pressure against the barrel but it is enough to cause problems.
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Think about it. If you went through all the trouble of making your gun have a free floating barrel for accuracy. Why would you let the barrel rest on anything. Attach your bi pod to the stock only. I have seen people trying to sight in their rifles resting the barrel on front sand bag rest and could not get them to print. After I pointed out the problem, the rifle settled right in.
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Everything in nature has its own 'frequency'. This frequency can be tuned, in rifles, by systems such ad the BOSS system and others. Some work by lengthening or shortening the barrel in small increments.
Induced electrical frequency is a little different than vibrational frequency in firearms, although they do overlap in the vibration department. I worked for years with electrical frequency to control the speed of machinery by regulating the hertz. Like changing the speed of a ceiling fan or dimming the lights through a dimmer switch, you are basically changing the speed (or cycle, hertz) of the flow of the electricity through the object. Standard flow of 120 volt appliances and such is 50 - 60 Hz. Take a potentiometer and drop that to 30 Hz and the item slows down (but the amperage increases and builds excess heat in the wiring if it is not heavy enough). Anyway, it is easy to get overly bogged down with this stuff, and it's been a few years since I've fooled with is. My old boss could explain it in better terms than I could because I'm not as good at getting some things out of my noggin and into written words.
The excerpt below explains harmonics as applied to firearms pretty well.
Stiffness
Stiffness of a barrel is proportional to the fourth power of the diameter, and inversely proportional to the third power of the length. Because of this, short, thick barrels will vibrate with high frequency and low amplitude, and long, thin barrels will vibrate with a low frequency and high amplitude. Due to the impact of length, barrel harmonics are primarily a concern with rifles. By using the shortest and/or fattest barrel possible, the amplitude of the vibrations can be minimized to the point that they are irrelevant to accuracy. Unlimited class benchrest shooting barrels, where weight is of very little consequence, have very large diameters; an outside diameter of 2 inches (5 cm) is not uncommon.
While standard rifle barrels taper from breech to muzzle, high precision rifles will often use a barrel with far less taper, called a heavy barrel, sometimes leaving the barrel cylindrical all the way to the muzzle, called a bull barrel. Either technique greatly increases the stiffness of the barrel by enlarging the average diameter, but this process adds significant weight as well. This can greatly increase the mass of the barrel, however; going from a lightweight sporter contour to a heavy barrel contour can double the mass, and a going to a bull barrel contour can more than triple it. Fluting, consisting of grooves machined in the outer surface of the barrel to remove material, can reduce the weight while maintaining most of the stiffness.
Barrel tensioning devices are a way of gaining stiffness with minimal increases in weight. They do this by using placing a lightweight sleeve, often made of aluminium or a carbon fiber composite, around the barrel, and then using a nut attached to the end of the barrel to tension the barrel and place the sleeve under compression. This serves to keep the muzzle closer to concentric and coaxial to the breech during vibration.
Harmonic tuning
The other solution is to work with the barrel's natural vibration, and tune the components so that the bullet exits the barrel as it is moving the slowest. The simplest approach to harmonic tuning is to concentrate on the ammunition. The internal ballistics of a given cartridge will determine its dwell time, or the time it takes from ignition to exiting the barrel. By experimentally matching the dwell time to the barrel's frequency, the best load for a particular firearm may be found. Similarly, handloading gives the shooter the opportunity to very precisely control the bullet velocity, and experimentally choose the optimum velocity.
If it is not possible or desirable to match the bullet to the barrel, there are a number of devices marketed to allow the barrel to be tuned to match the ammunition. There are a number of models of these that work in different ways. One type uses an adjustable damper or pressure bedding point to allow the shooter to find the "sweet spot", where it will do the most good at damping the vibrations that are affecting accuracy. Other tuners work by using an adjustable weight on the muzzle to alter the length of the resonant portion of the barrel, and allowing the frequency to be matched to the ammunition.
http://en.wikipedia.org/wiki/Accurizing
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Would a full length stock using barrel bands cancel out the vibration in a set up similar to this
http://www.ruger.com/Firearms/FAProdView?model=17143&return=Y
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My shoulder hurts just looking at the photo of that Ruger.
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My shoulder hurts just looking at the photo of that Ruger.
Its hell on the zombies though, particularly with the 458 Lott. ;D
FQ13
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Would a full length stock using barrel bands cancel out the vibration in a set up similar to this
http://www.ruger.com/Firearms/FAProdView?model=17143&return=Y
I wouldn't think this would be ideal. You are still connecting the barrel to the wood stock via the band and are, once again, going to be at the mercy of temperature and humidity making the wood swell and move, therefore, affecting accuracy.
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I wouldn't think this would be ideal. You are still connecting the barrel to the wood stock via the band and are, once again, going to be at the mercy of temperature and humidity making the wood swell and move, therefore, affecting accuracy.
You're one hundred percent correct. That's why we free float barrels. I've never understood the European preference for this design, it only adds weight. However, in dangerous game calibers, like the ruger, the weight makes sense in terms of felt recoil. It also adds stiffness and protection to the barrel, the same reason it was standard on military rifles for generations.
FQ13
PS For dangerous game rifles like the Ruger, accuracy isn't the primary concern. What you want is good enough, and all the time. Its like an SD pistol. Is it enough gun? Can it hit the center of the brown, or spots or gray or whatever? Will it go bang no matter what?
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TW this is a great question and subject, and as you see a lot of variables come into play. I'll try to make some parallels that make sense.
1) Barrels swell and vibrate when a bullet is passing through it, .22 rimfire and up. Imagine the barrel as a diving board. Depending on the weight and speed of the diver jumping on it, it will flex a lot or a little. A stiffer diving board takes more energy to flex, this is why we like stiff barrels. If there were something under the diving board that it touched during the flex, that would influence it as well, a light load might not make it come into contact with the object, but a heavier one would. This is why we like free floating barrels. If you put something under the diving board that touches it from the beginning, it is going to influence it a lot, change the characteristics of the board completely. Like a bipod on the barrel or resting the barrel on anything, sand bag, fencepost etc...
2) Frequency and amplititude. And why it matters.
Frequency is how many times something happens over a specific amount of time, amplitude is how far it moves in this context. Take the diving board example again, you flex the board and it goes up and down during and after the load has been delivered, it will continue to go up and down until is settles. How many times it went from center, to up and down, is the frequency, how far it moved, up and down is the amplitude.
Now imagine your barrel as the diving board, as the bullet go's through the barrel, the end of the barrel is beginning to whip, depending on the frequency, the bullet may exit one time on the up cycle and the next on the down cycle, there fore the bullet will vertical string the shots. Depending on the amplitude, the distance the muzzle moves during the cycle and when the bullet exits, can make more distance between the shots on paper.
Skinnier barrels move more, thicker barrels move less.
Thicker barrels are more resistant to movement from outside sources, like touching the stock or a bipod, or resting on a fence post, but it still makes a difference. Just less of one.
Fine tuning your loads, can reduce the frequency and amplitude, the idea is to have bullet exit as close to the beginning static position of the muzzle as possible, therefore less dispersion.
Out side influences like the stock touching the sides of the barrel or loose stock screws cause the horizontal or all over the place groups, especially as the barrel gets hot, cold metal is stiffer than hot metal, not uncommon for a skinny barrel hunting rifle to shoot the 1st 3 shots very well, and then open up quite a bit.
Hope I satisfied ya - HAZ
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............
Hope I satisfied ya - HAZ
He deserved that..... ;)
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Several years ago, Precison Shooting magazine did a series of articles on barrel dampening. Basic conclusions as I remember them, is that yes, dampers do affect accuracy. Vibration waves were checked, like waves in oscilloscope waves, and the authors concluded that where you put the damper will make a difference. Also where you cut a barrel will make a difference. One guy talked about rimfire rifles where he preferred barrels longer than 20" and slimmer rather than 20" or shorter but thicker. It was interesting reading but did get confusing in some parts. Isn't Tatical Solutions marketing a barrel damper that they claim is pretty good. Winchester and Browning had their version, "The BOSS" on their rifles for a while.
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I wouldn't think this would be ideal. You are still connecting the barrel to the wood stock via the band and are, once again, going to be at the mercy of temperature and humidity making the wood swell and move, therefore, affecting accuracy.
I'm aware of that, but my question, like the thread, pertained specifically to the harmonics question.
You guys are wimpy, click on the specs, the pictured rifle is a .308
My shoulder hurts just looking at the photo of that Ruger.
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Tom as a lifelong machinist, you will be able to absorb this better than most. Dampeners, work, it dampens the vibration = frequency , I doubt you have ever turned brake rotors, but when this is done, We have a larger rubber band that is wrapped around the outer diameter of the disc to dampen vibration, without it, the finish will be coarse, not withstanding the speed or the feed. But with the rubber band the finish is very smooth. The rubber has a dampening effect, some of the stuff like Limbsaver barrel dampeners can work, if you work with it, move the dampener up and down the barrel, it is just a large rubber collar, but it does absorb vibration, = frequency, and will effect amplitude, but not to a great degree. Now the Boss system, it varies the muzzle pressure, and the muzzle is what we are concerned with as far a accuracy. The less muzzle up and down variation, we get, the better the grouping. The Boss is a variable muzzle brake, but does have good effect.
More questions are welcomed.
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He deserved that..... ;)
No I didn't!
::)
;D
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I knew a guy years ago who, using spindle speeds with a long tool, programed his milling machine to play "Mary had a little Lamb". I have also seen a set up that required a weight on one side of the tool to eliminate chatter.
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You guys are wimpy, click on the specs, the pictured rifle is a .308
You got me Tom. ;)
Even so, that is one ugly ass rifle.
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Tom as a lifelong machinist, you will be able to absorb this better than most. Dampeners, work, it dampens the vibration = frequency , I doubt you have ever turned brake rotors, but when this is done, We have a larger rubber band that is wrapped around the outer diameter of the disc to dampen vibration, without it, the finish will be coarse, not withstanding the speed or the feed. But with the rubber band the finish is very smooth. The rubber has a dampening effect, some of the stuff like Limbsaver barrel dampeners can work, if you work with it, move the dampener up and down the barrel, it is just a large rubber collar, but it does absorb vibration, = frequency, and will effect amplitude, but not to a great degree. Now the Boss system, it varies the muzzle pressure, and the muzzle is what we are concerned with as far a accuracy. The less muzzle up and down variation, we get, the better the grouping. The Boss is a variable muzzle brake, but does have good effect.
More questions are welcomed.
Just a note on the BOSS...... the system has both a muzzle brake (with holes) and a solid unit (no holes) that has no recoil dampening effect (usually used when hunting without hearing protection).
The BOSS dampens by, as you previously stated, varying pressure at the muzzle, by changing the length of the pressure expansion area at the end of the barrel. The same unit works for all calibers except .338 Win Mag and .375 H&H.
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I would really like to know why it does not work with .338 and .375, physics are the same.
Tom as happens with certain things, you as a machinist have not had less than perfect circumstances, have you ever started a piece and felt the vibration?? And if you just put your hand on the work, being machined, felt it calm down?? Now this does mean something is wrong, and you probably stopped and adjusted the tension on the vise, or the angle of the cut, in our less than perfect world, sometimes we put our hand on it, and complete the cut. I am an amateur machinist, but have learned a lot, I have been cutting brake discs for 30 years and dampening bands have always been a part of the process,. But I will defer to a master machinist every time. It seems that you have not used this particular technique though??
Haz, I answered the question with a lot of detail, why do you doubt me??????????????
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O.K. I have a question. When we work up a load, we are basically finding a load that works with the harmonics of the rifle.
If we were to use one of these de-resonators, we just pick a load and adjust the de-resonator until the group tightens up?
Would that work?
It would seem easier to move a rubber block up and down the barrel rather than trying to dial in a load.
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O.K. I have a question. When we work up a load, we are basically finding a load that works with the harmonics of the rifle.
If we were to use one of these de-resonators, we just pick a load and adjust the de-resonator until the group tightens up?
Would that work?
It would seem easier to move a rubber block up and down the barrel rather than trying to dial in a load.
Thats basically what the BOSS promises. Pick a load, mess with the compensator to optimize it, and you're good. It seemed a bit gimicky to me, and I chose a Ruger over the Browning, but its an interesting concept.
FQ13
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I would really like to know why it does not work with .338 and .375, physics are the same.
Tom as happens with certain things, you as a machinist have not had less than perfect circumstances, have you ever started a piece and felt the vibration?? And if you just put your hand on the work, being machined, felt it calm down?? Now this does mean something is wrong, and you probably stopped and adjusted the tension on the vise, or the angle of the cut, in our less than perfect world, sometimes we put our hand on it, and complete the cut. I am an amateur machinist, but have learned a lot, I have been cutting brake discs for 30 years and dampening bands have always been a part of the process,. But I will defer to a master machinist every time. It seems that you have not used this particular technique though??
Haz, I answered the question with a lot of detail, why do you doubt me??????????????
Never said I doubted you , my friend. Just HAD to throw a few jabs (hey, it's a failing of mine. ;) )
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I would really like to know why it does not work with .338 and .375, physics are the same.
Tom as happens with certain things, you as a machinist have not had less than perfect circumstances, have you ever started a piece and felt the vibration?? And if you just put your hand on the work, being machined, felt it calm down?? Now this does mean something is wrong, and you probably stopped and adjusted the tension on the vise, or the angle of the cut, in our less than perfect world, sometimes we put our hand on it, and complete the cut. I am an amateur machinist, but have learned a lot, I have been cutting brake discs for 30 years and dampening bands have always been a part of the process,. But I will defer to a master machinist every time. It seems that you have not used this particular technique though??
Haz, I answered the question with a lot of detail, why do you doubt me??????????????
I had not read this when we were in the chat room, you are right, If I have vibration in the Work piece I have a problem.
Depending on tolerances it can be enough to scrap the part and will probably lead to tool breakage. I make sure the vice itself is secure and clamp down tighter. (there are sometimes other concerns like clamp torque specs but they are not relevant here)
No I never did that type of machining that you do, it was always new manufacture from castings in fixtures, flat or bar stock, so I have not used those bands.
It's why I said we had to wait for you ;D
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Re: Barrel Harmonics Question RE: Accuracy & Accessories.
« Reply #10 on: Yesterday at 11:52:15 AM »
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Everything in nature has its own 'frequency'. This frequency can be tuned, in rifles, by systems such ad the BOSS system and others. Some work by lengthening or shortening the barrel in small increments.
Peg, How do you lengthen the barrrel?
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Re: Barrel Harmonics Question RE: Accuracy & Accessories.
« Peg, How do you lengthen the barrrel?
One of those plastic pump thingies? ;D
FQ13 who will be in the corner
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M25, thank you for the explanations in a manner that a simple man can understand. I had the concept in my foggy mind and you helped to clear it up some. The Ruger Mini 14 has one of those wimpy barrels on it that probably suffers from this based on a lot of the accuracy complaints I've heard. The newer ones have a bit heavier tapered barrel and the target one has an adjustable thingy on the end. For years guys have been adding differant kinds of brakes, flash hiders, and shortening the barrels with various degrees of success. In addition some mess with bolt buuffers, piston buffers, and differant sized gas port bushings. I think what happens is that sometimes they get lucky and hit a sweeter spot and get much better accuracy. Some use this device or variations of it, or some times similar homemade devices.
http://www.perfectunion.com/vb/forumdisplay.php?s=59b0980af269614eb2cd064389f0cf06&f=106
Clark Custom guns use to offer a rubber donut of some type for the Mini, but have dicontinued them.
On the Ruger 10-22 carbine model I've know people to either remove the barrel band or relieve the inside of it as it is for show and is not needed to secure the stock. As far as the international full stocked model mentioned earlier the front nose cap may not even touch the barrel. I haven't looked at one in a long time, but seems to me it it was fastened to the stock and the muzzle end of the cap had a larger hole or channel in it than the barrel diameter. By the way I love the looks of the Ruger international model bolt guns and think they are a beatiful, classic, artistic design.
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I would really like to know why it does not work with .338 and .375, physics are the same.
Tom as happens with certain things, you as a machinist have not had less than perfect circumstances, have you ever started a piece and felt the vibration?? And if you just put your hand on the work, being machined, felt it calm down?? Now this does mean something is wrong, and you probably stopped and adjusted the tension on the vise, or the angle of the cut, in our less than perfect world, sometimes we put our hand on it, and complete the cut. I am an amateur machinist, but have learned a lot, I have been cutting brake discs for 30 years and dampening bands have always been a part of the process,. But I will defer to a master machinist every time. It seems that you have not used this particular technique though??
Haz, I answered the question with a lot of detail, why do you doubt me??????????????
They have one for those calibers. What I meant was that one unit works for all but those and the other unit works for them. It also has different threads so they can't be confused.
Re: Barrel Harmonics Question RE: Accuracy & Accessories.
« Reply #10 on: Yesterday at 11:52:15 AM »
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Everything in nature has its own 'frequency'. This frequency can be tuned, in rifles, by systems such ad the BOSS system and others. Some work by lengthening or shortening the barrel in small increments.
Peg, How do you lengthen the barrrel?
The barrel itself is not lengthened as to the rifling itself, just the overall rifle length to a minute extent. Pardon me on that one, I was in a hurry... and trying to get on screen what was in my head (that's why I'd never be a teacher because it don't always come out how I mean). The unit itself is 2" long and has about 3/4" of in/out adjustment. If you screw it out to make a larger chamber, it does in effect lengthen the overall length a little....but that's not what I was trying to say....I just muddled it up.
Now, what it does, according to Browning, and also as M25 explained in an earlier post, is vary the pressure of the escaping gasses (like an expansion chamber) in order to hopefully create equal pressure all the way around the bullet as it exits the rifling. Any minute pressure imbalance as the bullet exits will cause deviation. That's also the reason for some recessed target barrels, as they square the rifling to the barrel to optimize exit pressure around the bullet as it leaves the barrel. That's why you get that almost perfect star pattern on the end of a target muzzle from powder and gasses.
And for those who wonder, the BOSS works. At least mine does. My A-Bolt .308 will shoot just as accurately out to 600 yds with 168gr bullets as my friends Remington 700 Heavy varmint rifle. It just heats up quicker after a string of shots, as with any light barrel, and then all bets are off for tight MOA work. That's why it's a hunting rifle and not a bench rifle.
Dave Petzal wrote a good article on sub-MOA accuracy in the July 2008 issue of Field & Stream, but I can't find it online.
The gist of the article was that for a rifle to be accurate, it needs to be as solid as possible at the receiver, the barrel needs to be exactly true to the receiver, the bore axis needs to be square to the barrel, and thus to the receiver, the muzzle needs to be also square, and everything needs to be tight and rigid.....think benchrest rifle.
If anyone finds the article, please post.
Hope that clears up my mis-leadings.
8)
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And now that I'm done with my 'mater samich, I can say that run a lathe a time or dozen, m25 is right about the vibration.
Like he pointed out with the brake rotor trick.
Think of a tuning fork.
Whack it on something and what happens?
It vibrates at a certain frequency.
Now...wrap a rubber band around the fork and whack it again and see what happens.
And now.....how 'bout another 'mater samich?
8)
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(that's why I'd never be a teacher because it don't always come out how I mean).
Good Lord Peg! If that was the criteria, I would have been fired long ago. As it is, I have had about 3 discussions with a department head starting with "YOU SAID WHAT"? My response was always "What I was trying to get across was.......". I have been to the corner long before I met M'Lette. ;D Don't sweat it, although the making the barrel longer bit was amusing.
FQ13
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The M77 has a 26" free floated barrel, & bedded action. The Limbsaver damper did make a difference. Huge? No. Measurable? Yes. At 200 yards (longest range I have access to without a serious drive)
(http://i703.photobucket.com/albums/ww40/BigCheeseStick/P1000876.jpg?t=1240777228)
I started with it at the muzzle shooting five shot groups, moved it back aprox. two inches each time I shot another group until I had it all the way back to the stock. I checked for the best group and then repeated the whole thing a second, and third time to check for consistancy and find the "sweet spot".
At 200 yards I saw an average of about .230" improvement with the damper where its at over my groups without it on the gun at all. To be sure I get it back in the same spot in case it gets moved I marked the barrel with a sharpy. I dont like the way it looks. But I'm confident it works.
I'm sure a different load in the same gun would need different tuning.
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The M77 has a 26" free floated barrel, & bedded action. The Limbsaver damper did make a difference. Huge? No. Measurable? Yes. At 200 yards (longest range I have access to without a serious drive)
(http://i703.photobucket.com/albums/ww40/BigCheeseStick/P1000876.jpg?t=1240777228)
I started with it at the muzzle shooting five shot groups, moved it back aprox. two inches each time I shot another group until I had it all the way back to the stock. I checked for the best group and then repeated the whole thing a second, and third time to check for consistancy and find the "sweet spot".
At 200 yards I saw an average of about .230" improvement with the damper where its at over my groups without it on the gun at all. To be sure I get it back in the same spot in case it gets moved I marked the barrel with a sharpy. I dont like the way it looks. But I'm confident it works.
I'm sure a different load in the same gun would need different tuning.
Nice bug out bag Badger. Looks a lot like mine.;D The only difference is that I've got a Saiga AK rather than the AR plus a Maverick 88 security 12 gauge, but M77 and Glock, can't go wrong.
FQ13
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Well for what it is worth I have a Savage model 10 .204 Ruger that simply would not shoot. I tried a deresonator on the barrel and after shooting/moving, shooting/moving, etc. I found that sweet spot and the groups are now very tight. I was really surprised it worked as well as it did. I think for those who have had bad experiences with the product they did not try it thoroughly enough, i.e. they did not move it up and down the barrel and shoot groups with it. Remarkable in my case. Very pleased. Bought another one for my Win model 70 heavy barrel .22-250 to try and settle it down will let you know how it does on that one. Hope this helps!
Wheelgun
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Well for what it is worth I have a Savage model 10 .204 Ruger that simply would not shoot. I tried a deresonator on the barrel and after shooting/moving, shooting/moving, etc. I found that sweet spot and the groups are now very tight. I was really surprised it worked as well as it did. I think for those who have had bad experiences with the product they did not try it thoroughly enough, i.e. they did not move it up and down the barrel and shoot groups with it. Remarkable in my case. Very pleased. Bought another one for my Win model 70 heavy barrel .22-250 to try and settle it down will let you know how it does on that one. Hope this helps!
Wheelgun
Could you give us info on brand, price, where to buy etc.? I am very happy with my Ruger M77 .270 (about .75 moa off the bench and minute of bottom of beer can at 100 yards seated Two out of three anyway, but I scare the crap out it with that third shot). ;D Its the third shot thing thats resonating with me (pardon the pun but I couldn't resist). The first shot is ALWAYS the the most accurate. If sticking an ugly rubber dughnut on the barrel will help, I'm all for it. Hell, the deer won't complain.
FQ13
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Not kidding, try two dampeners, even 3, more dampening could be real good. Might be ugly, but I've beat a lot of competitors with ugly guns.
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If it works it isn't "Ugly". It has CHARACTER ;D
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Quaker, Thanks. I'm a big believer in using a common caliber between deployment firearms (.308 in this case). Sure would be great to have a second bag ready to go in 7.62X39! Russian's sure knew how to make their gun's, & the world will likely never know a more successfull combat firearm than the AK.
I just need to figure out the right answer to the long range question in that caliber... Been working on it for some time now. :-\
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Probably have to go with 7.62 X54 for long range, even if the the X39 does have the accuracy it does not have the range, look at how high the sight rises on AK and SKS sights when adjusted for 500 yards.
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Quaker, Thanks. I'm a big believer in using a common caliber between deployment firearms (.308 in this case). . :-\
You and me both.If I can't find it at Wallmart (or pick your local big box), I don't want to own it. I don't care how good a round it is on paper, if I can't buy it today (or otherwise acquire it in a TEOTWAWKI scenario) its useless to me. The perfect should never be the enemy of the good enough,particularly in survival situations.And quite frankly, thats all my my Glock, my Maverick, and my Saiga are for. The M77 is for hunting, but, its also there if I ever have to take that extended camping trip in the Everglades.
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Tom, Roger that. 7.62X54 is an awsome caliber. I dont know of a semi-auto in carbine length though (what a muzzle flash that'd have!). If I found one I'd own it that day!
Wheelgun, Quaker, Verify if barrel temp is effecting your groups. If thats it the rubber donut probably isnt going to do to much good. Look into cryo treating. It can make a BIG difference! Call around to local machine shops and ask where they get stuff "stress relieved". Then ask that place if they can do cryogenic treating. They'll usually do a barrel fairly cheap, especially if you get more than one done.
Midway sells the Limbsaver donuts, Basspro, Cabelas, Dunhams, Gander Mountain, about all the sporting goods shops have em.
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Tom, Roger that. 7.62X54 is an awsome caliber. I dont know of a semi-auto in carbine length though (what a muzzle flash that'd have!). If I found one I'd own it that day!
Wheelgun, Quaker, Verify if barrel temp is effecting your groups. If thats it the rubber donut probably isnt going to do to much good. Look into cryo treating. It can make a BIG difference! Call around to local machine shops and ask where they get stuff "stress relieved". Then ask that place if they can do cryogenic treating. They'll usually do a barrel fairly cheap, especially if you get more than one done.
Midway sells the Limbsaver donuts, Basspro, Cabelas, Dunhams, Gander Mountain, about all the sporting goods shops have em.
Thanks for the advice. If you want a .308 carbine, Saiga makes them. The reviews, as I've said, put them on par with the mini-14. 4" groups at 100 yards, but it goes bang every time. They also sell for what a Mini-14 SHOULD cost, about $600 on gunbroker. At that price, I opted for the the 7.62x39 as it has less recoil, quicker follow ups, and cheaper ammo and was avaiable for $369. The .308 still seems like a good option though, if your sniper rifle use that same ammo. Check it out, but I offer no advice one way or the other. Just something to think about.
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Yep, both the rifles shown are .308. Limits how many ammo cans I've gotta take, and any possible confusion on which can to grab in a hurry.
I have an MAK 90, and Yugo SKS in 7.62x39. Like'em a lot. Have tons of ammo for them. Just not super happy with their penatration and energy over 70 yards or so.
I've often wondered about a 12 gauge in combat... So many variables though... Cant help but think of all the WWII vets that gave up their garands for 30 carbines (heard many stories on this first hand)... Over penetration, recoil, follow up shot speed, muzzle flash, noise level, accuracy, reliability, ease of handleing, reload speed, how many rounds can you carry, magazines vs clips vs individual rounds, rate of fire... So many variables between the 12 ga. and the 7.62x39 and 30/06. .308 seems a good common ground. So many variables though!!! ???
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Yep, both the rifles shown are .308. Limits how many ammo cans I've gotta take, and any possible confusion on which can to grab in a hurry.
I have an MAK 90, and Yugo SKS in 7.62x39. Like'em a lot. Have tons of ammo for them. Just not super happy with their penatration and energy over 70 yards or so.
I've often wondered about a 12 gauge in combat... So many variables though... Cant help but think of all the WWII vets that gave up their garands for 30 carbines (heard many stories on this first hand)... Recoil, follow up shot speed, muzzle flash, noise level, accuracy, reliability, ease of handleing, reload speed, how many rounds can you carry... So many variables...
It just depends on what you want it for. In the house, a 9mm. Across the yard, 12 gauge buck. Across the street, a carbine (choose your flavor). If I have to get out the .270 for that 300 yard shot, the poop has hit the fan and then some. Dress approriately, your mileage may vary.
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The devistation of a 12ga slug is tough to argue in any use under 100 yards. Big effect on enemy moral seeing that kind of damage done!
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The devistation of a 12ga slug is tough to argue in any use under 100 yards. Big effect on enemy moral seeing that kind of damage done!
When I was in ROTC, a cadet fell off a 50 foot tower in an obstacle course.What I learned (among other things) is that bleeding and screaming, is bleeding and screaming. It doesn't matter the cause. Everybody from the greenest cadet to the most harded NCO, was shook up to the point of nausea along with that lovely clammy feeling that goes with putting a friend into an ambulance knowing its a waste of gas. I don't care what you shoot him with, you will have his buddies undivided attention, for good or ill. I would chose my weapon based on the likely tactical environment,not anticipated psych effect. Just my .02.
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A good point. And head shots from any caliber rarely go without drama!
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Badgersmilk
Tell me a little abot that bag you've got. It looks handy. Also what kind of scope and what kind of accuracy are you getting out of that M77? I havea B@L Elite 3000 in .270 on mine and love it, but I always want to learn.
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the bags from VooDoo Tactical. Holds two long guns (the 26" barreled M77 JUST fits) and two pistols, binoculars, spare mags for each, spotting scope, range finder, Ghilli wrap for the M77, and a bunch of other crap (yes this makes for one HEAVY puppy!), but its super durrable, and came with backpack straps I use instead of the shoulder strap (did I mention its HEAVY?). Grab this one bag, a small duffel with a Ghilli poncho and other crap in it, several ammo cans and your all set to travel (maybe not through an airport though!)
The scope: http://www.bushnell.com/general/riflescopes_elite3200_32-1040m.cfm
As far as accuracy... Thats all about me. Has nothing to do with the gun, ammo (hand loads), sights, rest, the trigger (breaks clean at 13 oz.) or anything else. That stuff's all proven 100% reliable, and consistant. I have NO excuses there. I know the gun outshoots me. When I can settle my stupid butt down. Start using my brain, and go through my check list, I'll consistantly stay in 1.2" at 200 yards. Not muraculouse. And no fault of the hardware. That's just me (when I use my brain). Shooting one group thats .19" at that range doesnt prove anything unless you can do it every time. I cant!
Could probably do better with more scope, and if I shot more, but more scope isnt practical for what the gun was built for. (Quick aquisition & fire at range). And given the amount of time it takes me to hand load precision rounds... I dont care to burn through them any faster than I already do! ;)
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Could probably do better with more scope, and if I shot more, but more scope isnt practical for what the gun was built for. (Quick aquisition & fire at range). And given the amount of time it takes me to hand load precision rounds... I dont care to burn through them any faster than I already do! ;)
Plus 1 on the 12g, a slug is alot of lead, and 7 or 8 rounds of 9 pellet .30 cal buck is more, that's 72 piece of lead faster than any AR or AK, its effectiveness in certain situations could be argued though. You ever looked at a Jeff Cooper style scout rifle?
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1.2" at 200 yards is damn solid. I can shoot .75" at 100 yds on the range and put the first two out of three on a beer can at two hundred (the third shot is iffy, but damn close, hence my interest in the doughnut to compensate for the barrel heating up). I don't understand why more folks don't look at the Ruger before going to the rem 700 as a default. Just because the army chose it doesn't mean its better.Hell, compare the the Glock to the Berretta as exhibit A. :P Anyway, thanks for the info on the bag.
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Fire two shots within a minute, then wait about 10 minutes and fire the third. Some barrels are more sensitive to fouling than others. It could be this rather than heat causing your third shot problem. Could also be the ammo, or the load your using is causing excessive fouling in your particular gun. Check those things before you spend any money modifying the gun. I dont think you can go wrong with Cryo treat though. (I put A LOT of work into tuning my M77... If your using the factory scope rings you might consider going to Burris steel ones to. Helped my gun!)
I love Ruger's, have several I'm super happy with (little .44 carbine may be my favorite). But every model I've seen you had to be SUPER carefull looking over their guns before buying one. All their guns I've looked at I could pick one or more out of the bunch that'd been VERY well built. Then I'd find one or more that were JUNK. Rugers problem has been consistancy in quality ever since the mid. 80's. If you dont look SUPER close its a crap shoot. Still one of my favorite manufactures of all time though!
Rem. 700's... The factory stock guns dont impress me in the least. Aftermarket stuff is plentiful, as are special models (m24), and as nice as you care to pay for.
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While installing some water lines to some pecan trees this morning, I thought of something that might readily demonstrate M25's excellent 'diving board' analogy from one of his earlier posts regarding barrel harmonics.
Take a piece of 3/4" PVC pipe and hold it in the middle and shake it. Then drop a marble or anything that will roll down it into one end, while still shaking the pipe. There are no guarantees where the object will go when it exits the pipe.
It's a very exaggerated example, but still shows what barrel flex will do.
Stiffen the pipe, or remove as much flex as possible, and you can control where the object goes a little better.
Same thing with rifle barrel harmonics.
The rubber dampeners remove some of the excess vibration.
Accuracy kinda boils down to timing, in a way, though. You are basically timing when the bullet leaves the barrel, during the vibration cycle of the barrel. Thinner barrels flex and 'whip' more than thicker more rigid barrels, but all barrels flex to some degree. I've seen benchrest barrels that were 2" in diameter to try to remove flex, just to shoot a 6mm bullet. But a 2" barrel ain't real handy in the deer woods.
Bottom line, remove as much vibration (harmonics) and as many other variables as possible and then work up the load (or test factory ammo) to find the round that is most consistent at leaving the barrel at the same time in the cycle of movement. Also bearing in mind that the load itself will have an effect on the vibration cycle, but you have to start somewhere.
This has been posted several times........Watch at about the 00:27 mark.
http://www.youtube.com/watch?v=s5pVya7eask
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Sure makes it easy to see where cheap scopes would fail on any kind of rifle!!! Even 1/4 of that flex is mighty tough on something precisely holding little peices of glass!
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That is the only major problem I've found with the Soviet weapons, near/ Far require different calibers.
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Something mentioned early in this thread was tensioned barrels, which I have seen but not shot except for a 10/22 barrel from a custom manufacturer, and that barrel did shoot very well compared to a factory 10/22, and unbelievably light. These are barrels that use a carbon fiber sleeve, over a really thin barrel, and a gland nut at the end, when tightened, pulls the actual barrel in 2 directions, ( guess which ) and that dampens frequency and amplitude, light weight and accurate, but they were too expensive for me to try, but I wish I had a buddy with one to try out, those hunting rifles were in the 5.5 - 6 lb range with 24" - 26" length. Dan Wesson used this technique and were known for their accuracy, and now S&W is using it on a few models.
I have had some oldtimers describe a Freeland product used on position target rifles in the old days, that does make sense. 1st the fore end has some metal ferules installed, that are threaded, placed at 45 degrees to each other near the far end of the forestock, into which you have threaded brass screws that are screwed in until they just touch the freefloated barrel. You had adjustable tension on the unsupported portion of the barrel and could play with it a little, just like using business cards to shim a hunting barrel, if your light weight don't want to shoot. A lot of times that shim will tighten things up, if it does We will usually glass bed the last 1 inch of the stock, to put just a little pressure on the barrel at that point, once again changing the harmonics. Free floating usually works the best, but some rifles like a little pressure.
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Magnum Research. As fine a .22 as man will ever know!
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