Forbes Rifle bedding

44marty · Posted: Mon Jan 09, 2012 10:36 am Post subject: Forbes Rifle bedding

I am reading the article in the Jan. American Rifleman on the Forbes rifle. It has a carbon fiber reinforced Kevlar stock. The part that has me thinking:
"Melvin Forbes believes full contact between the barreled action and stock dampens vibrations, enabling bullets of differing weights to impact closely, as well as enhancing accuracy. As such, the Model 24B is glass bedded from the tang area to the tip of the fore-end. Transposing targets during testing confirmed his belief."

Hmmmm. I have always been a firm believer in free-floated barrels for accuracy.

Any thoughts / comments??

Ominivision1 · Posted: Mon Jan 09, 2012 11:05 am Post subject: Re: Forbes Rifle bedding

I also read that article and I always thought a free floated barrel gave the best accuracy. Barrel harmonics is a hotly contested item in my neck of the woods. One of the guys at the club is a professor at ISU and according to his views the best way to get rid of harmonics is to dampen them.

Makes sense when you figure for a 3000fps bullet to exit the barrel takes approximation 0.0010 seconds and the speed of sound is 14,900 fps in a stainless barrel. It makes sense because the sound waves can travel 4 times up and back in the barrel before the bullet exits.

He took his older M700 30/06 and muddied up (bondo) the cavities in the stock and set the barrel down onto the oozing bondo. 3 days later he bought that rifle to the range at that gun went from 2.50" groups to 1.60" groups at 100 yards. He used the same loads before and after his test and even thou I seen it, it was just one test with 30 rounds each before and after. Weather conditions were the same for both tests.

I'm still on the fence about this.

chambered221 · Posted: Mon Jan 09, 2012 12:59 pm Post subject: Re: Forbes Rifle bedding

I've come to the conclusion both methods work !!!

Benchrest shooters have experimented with full bedding of the barrel and found it to work. However the consistently low aggs are shot with free floated barrels.

Custom hunting rifles build by Ultra Light Arms and others use the full bedding method to control vibrations of the light weight barrels they use in their builds.

Donut Slayer · Posted: Mon Jan 09, 2012 1:06 pm Post subject: Re: Forbes Rifle bedding

rimfire shooters, the 10-22 variety, will bed the barrel and free float the action. Just bass-ackerds of common beliefs.

Suzanne · Posted: Mon Jan 09, 2012 3:20 pm Post subject: Re: Forbes Rifle bedding

Maybe it's the caliber and it's effect on barrels of varying densities. 22 rimfire with a heavy enough barrel might not effect barrel harmonics all that much, but you'd think they would bed the action too, so that whatever vibrations from the action would be null.

Maybe if you bed the entire works it's easier to tune a cartridge to the barrel. Whereas a free floated barrel is bouncing around more and you have to tune the cartridge to the (possibly more frequent) harmonics of the barrel. The less harmonics you get, the less you have to do, to fine tune a cartridge.

I'm with Chambered, I think both methods work but I think they work at random. One way might be good for one rifle and if it's not then try the other way. You're balancing barrel harmonics with the cartridge and one way might be a closer fit than the other, therefore less need to fine tune a round. I do believe one has to be tuned to the other for optimum groups but I think if you start with the bedding and find out which way works best, then fine tune the cartridge. Only thing is bedding is tough to remove.

Suz

slimjim · Posted: Mon Jan 09, 2012 7:17 pm Post subject: Re: Forbes Rifle bedding

I've done both. I fully bedded a 10/22 and it made a significant improvement. I once tried it on a Rem 700 action with a composite stock because nothing else worked but showed no improvement (that was it, rifle was gone). I think a key factor is stock changes to environmental conditions. I wouldn't try this with a wooden stock unless using some stiff/thick carbon fiber to stabilize the stock to barrel interface. When a stock changes due to environmental changes, if it touches the barrel, its POI will change. I had a rifle that shot 1/2 MOA, just a different POI every time I went out.

inthedark · Posted: Mon Jan 09, 2012 10:23 pm Post subject: Re: Forbes Rifle bedding

My old Winchester 70 Post 64, 22-250 had a small slip of cardboard (like from a cigarette pack) that was inserted at the foreend of the stock and the barrel to create upward stress on the barrel. I took it out and the gun shot like crap. I put it back in and she shot fine.

chambered221 · Posted: Mon Jan 09, 2012 11:20 pm Post subject: Re: Forbes Rifle bedding

I believe in letting the harmonics of a quality barrel ring !!!

It's those not so good barrels that benefit the most with full bedding.

PaulS · Posted: Tue Jan 10, 2012 12:21 am Post subject: Re: Forbes Rifle bedding

If you have a carbon fiber reinforced Kevlar stock you can be pretty sure that changes in humidity and temperature don't cause any warpage in the stock so I can see that full length bedding will work well in that situation.
If, on the other hand, you have a wood stock you will likely have problems as the gun gets warm or the temps and humidity changes.
If you rest your gun on something when firing it there is always the chance that the weight on the fore-end will bend it slightly if it is in contact with the barrel.
I have always free-floated the barrels on all my rifles but then the stocks are all made of wood.

Ominivision1 · Posted: Tue Jan 10, 2012 4:18 am Post subject: Re: Forbes Rifle bedding

Here is another take on stabilizing the barrel. www.ruger-mini-14-fire.../index.php

SingleShotLover · Posted: Tue Jan 10, 2012 7:25 am Post subject: Re: Forbes Rifle bedding

chambered221 wrote:

I've come to the conclusion both methods work !!!

I guess I'm of the same opinion. I have had barrels that shot best with a slight amount of fore-end pressure and those that shot brilliantly with free-floated barrels (but well-bedded receivers). I have not had a rifle shoot well with a fully bedded barrel, but that's not to say such a critter doesn't exist.

Years ago I helped a friend glass-bed his entire action and barrel because he didn't want to risk getting moisture and debris between his barrel channel and the barrel. The results were groups that looked more like patterns and were in no way repeatable. We "hogged" out the bedding material in the forearm leaving only the receiver and about an inch of the barrel bedded and the rifle settled down to a bit over MOA. That is not to say that another rifle won't perform better if fully bedded; after all, each rifle is a law unto itself. I just haven't seen one yet.

fnuser · Posted: Wed Jan 11, 2012 8:52 am Post subject: Re: Forbes Rifle bedding

I still shoot one of my first stock projects it was a several guns purchased as parts from a couple of different sources the main component being an intermediate length F.W.Heym 98 barreled action in .30-"06. I thought I needed a full stock so I put it in a full length black walnut from Wenig's an glassbedded it by filling the entire thing with acraglass and wrapping it from muzzle to tang with tightly stretched inner-tubes. It shoots .25" with a 4x leup m-8 at 100 yrds. When removing the action from stock it is neccesary to pry the forearm off about 10" back from muzzle. It pops like Lego's in and out. While all of this is a happy accident it does provide a case for full contact.