F T/R Competition Heavy Barrel Bedding

[jsthntn247]

I've got a 30" heavy varmint modified #9 contour Bartlein on the way for an F/TR gun build. The barrel weighs about 7.5lbs and will be going on a trued 700 action. The contour on the barrel is straight for 5" then tapers down to .935. Do you guys recommend beding part are all of the first 5" of the barrel channel on a heavy barrel like this? I normally don't bed in front of the lug but the heaviest barrel I have is a Rem Varmint contour.

 

[XTR]

I bet you get a variety of answers. I have mine bedded for about an inch in front of the lug, lots of folks free float everything. I think it doesn't make a whole lot of difference.

 

[Down South]

Most smiths don't bed in front of the lug even with straight 1.25 30 inch barrels but i have seen guns shoot really well with a section of the barrel bedded. A friend of mine beds about 2 inches of barrel in his personal guns and they shoot very well so i guess theres more than one way to skin a cat so to speak. As for the guns i had built, they were not bedded past the lug and I used heavy varmit contour barrels.

 

[Ibelieve1776]

I am about to install a 28" bull and was wondering the same thing. I have been conversing with Nathan Foster whom manufactures Match Grade Bedding Compound he says when he beds heavy barrels he will go as much as 3" in front of the lug. He also has great YouTube videos on his bedding process.

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[cmh2007]

My smith does about 2 inches worth in front of the lug

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[Ridgerunner665]

It totally and completely depends on the barrel...some like bedding under the chamber, and some don't.

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[Frank Green]

For the most part I will say it doesn't matter. My rule of thumb is that anything up to the #9 HV and 28" or less in length no need to. If over 28" finish length or you start running a 1.250" straight blank then I would say yes. I also think the type of action being used can have a impact on this as well. Some actions have a longer thread tenon and give more surface area when you bed the action.

I'll have to look at my F-class open gun. It's built on a Barnard Model P action. The barrel is a .284win. and 1.250" straight x 32" finish length. The gun is a hammer and Moon put it altogether for me. Bedding everything. I'll look to see how he did it as I left it all up to him.

Later, Frank
Bartlein Barrels

 

[cdparker]

I have the same rig as Frank's. Mine is a hammer also--Thanks Frank! Now to the original thinking about bedding. The plan is to bed the front of the action so that there is equal support behind and in front of the front action screw. As an example-The Remington 700 and the Winchester M-70 action have the front screw set back from the recoil lug. Those type of actions are NOT usually bedded ahead of the recoil lug. The 98 Mauser and 1903 Springfield have the front action screw through the front lug. In order for those actions to be bedded correctly, they should be bedded so that there is equal support both in front of the front screw and behind it. That necessitates bedding under the shank of the barrel for a short distance. Given that, the rear action screw is bedded using a pillar. I personally use one in the front also. That way, the action sits in the stock in a stress free condition. The Barnard has a bedding block that the action sits on. Remember that the pillars do not touch the screws on their sides. Like Frank says the length of the thread tenon and the strength of the action are important in supporting a heavy barrel. Another thing to consider is that anything that touches your barrel will disturb the vibration node of the barrel as the bullet proceeds to the exit. Therefore, bedding under a portion of the barrel will move the vibration node of your barrel. This is similar to the science of a tuner at the muzzle. Creighton Audette wrote of this some years ago. There is an example of his work in The NRA Highpower clinic book Vol. 1 Originally done at Camp Perry in 1980. I believe it is still available from the NRA. That being said, If your gun is a hammer as it is--Do not change it.
Favor Center-Craig

 

[Blackbrush]

I've looked closely at the work coming from LRI, SAC, GAP and Gradous. Most them seem to be bedded for 2 or so inches.

 

[Frank Green]

I have the same rig as Frank's. Mine is a hammer also--Thanks Frank! Now to the original thinking about bedding. The plan is to bed the front of the action so that there is equal support behind and in front of the front action screw. As an example-The Remington 700 and the Winchester M-70 action have the front screw set back from the recoil lug. Those type of actions are NOT usually bedded ahead of the recoil lug. The 98 Mauser and 1903 Springfield have the front action screw through the front lug. In order for those actions to be bedded correctly, they should be bedded so that there is equal support both in front of the front screw and behind it. That necessitates bedding under the shank of the barrel for a short distance. Given that, the rear action screw is bedded using a pillar. I personally use one in the front also. That way, the action sits in the stock in a stress free condition. The Barnard has a bedding block that the action sits on. Remember that the pillars do not touch the screws on their sides. Like Frank says the length of the thread tenon and the strength of the action are important in supporting a heavy barrel. Another thing to consider is that anything that touches your barrel will disturb the vibration node of the barrel as the bullet proceeds to the exit. Therefore, bedding under a portion of the barrel will move the vibration node of your barrel. This is similar to the science of a tuner at the muzzle. Creighton Audette wrote of this some years ago. There is an example of his work in The NRA Highpower clinic book Vol. 1 Originally done at Camp Perry in 1980. I believe it is still available from the NRA. That being said, If your gun is a hammer as it is--Do not change it.
Favor Center-Craig

Hey Craig! Moon at Crescent Customs and former worker at GAP put my F-Class gun together for me. It's in a McMillan Tooley MBR stock. Moon didn't use the Barnard bedding block that came with the action. I know some guys use them and some don't. I left it up to Moon if he wanted to use it or not. Also Moon full floated my barrel up to the receiver. We talked about the bedding over the phone and I left my trust in him as to how he wanted to do it. Below is a pic.

Later, Frank
Bartlein Barrels

 

[Greg Langelius *]

My thinking, and this is theoretical, is that asking a tenon, and its corresponding area of the action, to support a long heavy contour is very near (or past) the limits of what's reasonable.

I also think that during firing, the barrel is doing things (like expanding and contracting under the influence of the pressure curve) that can disturb both itself and the action if they are both in contact with a rigid bedding surface.

I believe that the action should be bedded with a rigid compound, and at least the chamber portion of the barrel (which extends a bit behind the recoil lug in most cases) should also be bedded, but with a flexible compound (like RTV silicone, etc.) that can resist causing the barrel to rebound during its pressure curve-related motions.

I also suspect that establishing an upward preload force at the end of the barrel channel, also using a flexible compound, may have benefits as long as the upward preload force exceeds any other upward forces (due to harmonics) that may occur during the bullet's transit. This could possibly have an added benefit of building some upward component into the bore axis that serves a role similar to scope base slope.

Load development is based on matching bore transit time to barrel harmonics. I believe that there could be some benefit to making an attempt to tame the magnitude of those harmonics-related muzzle gyrations.

I also suspect that some of the newer thermal conducting silicone products could be used as an intermediate layer between a slim barrel and a highly thermal conductive barrel shell, improving heat transfer (cooling cycle time) and barrel stiffness, while reducing the overall barrel mass involved.

Again, this is all theoretical.

Greg

 

[BKS]

Hey Craig! Moon at Crescent Customs and former worker at GAP put my F-Class gun together for me. It's in a McMillan Tooley MBR stock. Moon didn't use the Barnard bedding block that came with the action. I know some guys use them and some don't. I left it up to Moon if he wanted to use it or not. Also Moon full floated my barrel up to the receiver. We talked about the bedding over the phone and I left my trust in him as to how he wanted to do it. Below is a pic.

Later, Frank
Bartlein Barrels

Moon put a barrel pad under the chamber area of my 300 RUM. It has a 30 inch, 1.25 straight Bartlein. It is on a 700, so maybe it depends on the action?

 

[leadbullet]

My FTR 308 has 4 inches of the barrel bedded, it shoots bug holes, a little stress relief to the receiver never hurts especially with long and heavy barrels on lightweight actions like the rem 700.

 

[Forgetful Coyote]

I was looking at 6mmbr.com Guns of The Week, and saw a Stevens that a guy built with, I want to say a 1.250" straight cylinder ad barrel block. I know a lot of people in benchrest use them, but are barrel blocks common in F-Open?

Thanks.

 

[cdparker]

Frank--Here is my gun. The stock is a Master Class. I got it unfinished with the bedding block and cheek riser installed by Alex. The butt hardware is shotgun Hardware. One more match and I get my HM card.
Provided I Favor Center ;^)

 

[Frank Green]

I was looking at 6mmbr.com Guns of The Week, and saw a Stevens that a guy built with, I want to say a 1.250" straight cylinder ad barrel block. I know a lot of people in benchrest use them, but are barrel blocks common in F-Open?

Thanks.

No. IMO barrel blocks on a F-Class rifle is not common. That's the first one I've heard of.

Later, Frank
Bartlein Barrels

 

[Frank Green]

Frank--Here is my gun. The stock is a Master Class. I got it unfinished with the bedding block and cheek riser installed by Alex. The butt hardware is shotgun Hardware. One more match and I get my HM card.
Provided I Favor Center ;^)

Alex at Master Class Stocks does great work! He restocked one of my other rifles last year for me! Great looking set up and it sounds like it's shooting great for ya! Congrats when you get the HM card!

Later, Frank
Bartlein Barrels

 

[Killshot44]

I have a 31", 1.25 straight tube on a Rem700 receiver.
I've shot barrels with 2" forward of the lug bedded and those with nothing beyond the receiver and found the unbedded barrels shot smaller at 600+ yds.
This is an F-Open gun in a Shehane ST-1000 stock.

YMMV

I've only seen two competitors using barrel-blocked guns in Open and they both shot well.

 

[cdparker]

I just thought of a point in favor of not using any bedding in front of the action. I have two Barnards. I like my stock so much that with the Aluminum bedding block in my stock, I can mix and match actions on the same stock. I actually have five different barrels that I can use in my actions. Three are in six point five and two are seven millimeter. All of the combinations shoot very well. I do have a separate scope for each action.
Works for me.
Craig

 

[Blackbrush]

I have a number of switchbarrels and as a result, I avoid a pad under the barrel

 

[Donald]

Both ways can work but Ive seen no bedding under the barrel work the best over a larger number of rifles, a small barrel block on a biggish barrel works even better.