Barrel Harmonics Question RE: Accuracy & Accessories.

[twyacht]

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.

[Rastus]

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.

[twyacht]

Sorry about the link, this one is identical.

http://www.varmintal.com/atune.htm

[1911 Junkie]

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.

[twyacht]

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.

[Sponsor]

[tombogan03884]

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 .

[Hazcat]

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?!

[tombogan03884]

Maybe "experienced" would be more appropriate  

[1911 Junkie]

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.

[1Buckshot]

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.