Barrel Harmonics Question RE: Accuracy & Accessories.

[m25operator]

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.

[Hazcat]

He deserved that.....   

No I didn't!

[tombogan03884]

 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.

[Ping]

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.

[PegLeg45]

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.

[Sponsor]

[m25operator]

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??

[1911 Junkie]

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.

[fightingquaker13]

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

[Hazcat]

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. )

[tombogan03884]

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