Eliminating or dampening barrel harmonics

[John_M]

About 30 years ago I had a Remington 700BDL "Varmint" in .243 Win. caliber. The gun shot very well (<1" moa). Then, one day I read an article in one of the gun magazines suggesting shooters bed about 1.5" of the barrel starting about 1.5" from the end of the forearm. The purpose of this short bedding is to eliminate or dampen barrel harmonics for better accuracy and more consistet Point Of Impact. I did this short bedding "improvement" and my 100 yd., 5 shot groups became one ragged hole shooting 42.5 grs. IMR4350 with CCI400 primers and the Hornady 87 gr. SP bullet.

My current Savage Model 10 in .223 Rem. is also a shooter and I have almost, but not yet achieved the desired 100 yd., 5 shot group into one ragged hole. The rifle has H-S Precision stock with the barrel having lots of free-float between it and the stock.

My question is this: Do any reputable gunsmiths or manufacturers, today, do this short barrel bedding procedure for better accuracy? I conducted searches at various shooting sites and could find no info.

I would like some opinions from others who might have tried some procedure like this.

Best wishes and good luck. ;)

[wbm]

Remington and Winchester used to have a raised "pressure point" on the forearm tip of their wooden stock rifles. Don't know if they still do that or not. I had a 303 Enfield and a 1903A3 that shot much better with about 10-15 lbs of upward pressure applied at the forearm tip. Free floated barrels are what most if not all manufacturers advertise in their rifles. Best way to find out if it helps your rifle is to try it. You can take a temporary shim and try it out.

[kslefty]

I agree, try it with something temporary first. Ruger uses a pressure point on their light weight barrels, can't say for sure on their heavy barrels. Another option would be one of the rubber dampening rings that slide over the barrel, some people claim they work.

[Shoot-N-Nut]

The biggest thing with pressure points is that it doesnt help every rifle. Over the years most have found that more barrels respond better to being floated then bedded. So using something temporary like foam tape will tell you if its going to help or not.

[davemuzz]

I don't know how you could possibly "eliminate" or "dampen" barrel harmonics. Maybe it's me, but I think those are a poor choice of words. From everything that I've read, plus my personal experience with bedding and floating forends, I would say it's bedding a stock and floating a forend in order to obtain "consistent repeatable" harmonics from a barrel. Then you can develop your reload to find out which one (or ones) work the best with that barrel harmonic.

MHO

Dave

[Blue Avenger]

easier then cutting 1/2" off to re-tune a barrel. Just some time and it can be undone.

[John_M]

Thank you all for the helpful responses. :smile-new:

I might try various thicknesses of foam tape in different locations along the forearm to determine the effect on accuracy. It will be an enjoyable experiment.

Good luck and best wishes to all.

[wbm]

I don't know how you could possibly "eliminate" or "dampen" barrel harmonics. Maybe it's me, but I think those are a poor choice of words. From everything that I've read, plus my personal experience with bedding and floating forends, I would say it's bedding a stock and floating a forend in order to obtain "consistent repeatable" harmonics from a barrel. Then you can develop your reload to find out which one (or ones) work the best with that barrel harmonic. MHO Dave

+1 Great post Dave!

Precision Shooting magazine had a research article a few years ago on barrel vibrations and harmonics. Research guy "wired" the barrels and hooked them up to a scope....then he "tuned" them. The increase in accuracy was amazing.

http://www.rifle-accuracy.com/harmonics.htm

[davemuzz]

Thanks WMB.....you know....even blind squirrels find an acorn... :) But, you are right about the 1-9 twist shooting the lighter bullets. I have a boat-load of the 40gr. Noslers left over after selling my Contender, and I've loaded these and shot 'em out of my Savage. They are not the one-hole at 100 yards the Savage is with the 68gr., but they are certainly accurate enough for close range crows, or any other "under" 100 yard critter you want to explode.

Dave

[scythefwd]

isnt the point of the BOSS system to tune harmonics?

[davemuzz]

isnt the point of the BOSS system to tune harmonics?

Yup. That's what the claim is. I can't vouch for it as I don't own a Browning with the boss. But, it makes sense. It's just a "big 'ol screw that torques against the barrel to change the harmonics until your bullet likes it. It's shooting factory.....and getting your harmonics to like it. Like "reloading in reverse" without the reloading part. :)

[scythefwd]

Thats how I understand it. And thats the same thought I had too about the reloading in reverse.. its a great idea though if you dont reload. There is a guy that was using a sleeved barrel that basically did the exact same thing.

[reloader]

you can also try the limbsaver deresonator slips over the end of the barrel about $10.00-$15.00, it helps with my browning 300wsm

[CJnWy]

Putting a couple of bissiness cards under the barrel helped the groups on the 7 mag when I tryed it BUT the point of impact changed depending on if I used the bipod,sling or rest. Have tryed it on a few rifles with the same results.
Sometimes I'll bed the tip of a prairie dog gun where it only gets shot in warm temperatures off the bench and bipods but the hunting rifles do better with freefloated barrels.

[kevin_stevens]

Yup. That's what the claim is. I can't vouch for it as I don't own a Browning with the boss. But, it makes sense. It's just a "big 'ol screw that torques against the barrel to change the harmonics until your bullet likes it. It's shooting factory.....and getting your harmonics to like it. Like "reloading in reverse" without the reloading part. :)

BOSS isn't an adjustable pressure point against the barrel, it's a weight at the muzzle that allows you to screw it in and out to adjust the harmonics. But yeah, for people like me who don't reload it's a way to adjust groups while sticking with a factory load.

KeS

[davemuzz]

you can also try the limbsaver deresonator slips over the end of the barrel about $10.00-$15.00, it helps with my browning 300wsm

OMG!!! These doughnuts are the butt ugliest chunks of rubber I've ever seen. I'd rather weld chunks of metal on my barrel than use one of these.

[reloader]

all i know which might be very little is it works very well on a browning a-bolt 3oowsm and a cz 550 american 308. those ugly little chunks of rubber are ugly, however they performed on 2 of my rifles, shrunk the groups by half

[CJnWy]

OMG!!! These doughnuts are the butt ugliest chunks of rubber I've ever seen. I'd rather weld chunks of metal on my barrel than use one of these.

I totaly agree but where exactly to weld the chunk of steel is what keeps me from doing just that!!
I got a kick out of my hunting buddies this year. They all shoot 7mags with the same load and all three doughnuts are in the same place on the barrel. Its alright though, it didnt hurt thier ability to miss:p

[davemuzz]

all i know which might be very little is it works very well on a browning a-bolt 3oowsm and a cz 550 american 308. those ugly little chunks of rubber are ugly, however they performed on 2 of my rifles, shrunk the groups by half

I almost hate to say this.....but.....sell those non-Savages rifles and replace 'em with.....well, you know.....an accurate rifle.

http://i12.photobucket.com/albums/a212/davemuzz/MrClx5GMV_vPV24x9qh.png

[Quickshot]

Davemuzz, Correct answer,,, You win two tickets to the next Steelers home game and a six pack of "ahrn city".