Gunsmithing Barrel touching stock with .120" clearance

[flyfisherman246]

My personal HTG stock with a bighorn tl3 and bartlein rem varm .308 win was showing signs of contact on the barrel and stock. Hitting so hard it wore through the cerakote. It had what I thought was plenty of clearance. So I opened it up to probably .050" which is what is recommended by Mcmillan. Fresh coat of spray paint on the inside, take it out to shoot it, take it apart, still making contact. The rifle was stringing vertically in the beginning, after opening it up it started shooting better. So I opened it up again to now what I would guess to be somewhere around .120" clearance. Take it out and shoot it, disassembly, still showing marks of contact on the freshly painted barrel channel at the end. Thought there is no way and something is going on here. Glass and pillar bedding are perfectly stress free and nothing is loose or shifting. I went ahead and redid the bedding just incase there was something going on. Take it out and shoot it, shoots really well, but still showing signs of contact.

My buddies rifle which is basically the same as mine except 22" .260 remington. I took it apart to check to see if his was making contact with about the .050" clearance and sure enough, it has been hitting so hard it wore through the cerakote as well. (Pictures below) Just squeezing the stock against the barrel at the tip of the stock does not take much pressure at all. If I take some manners carbon fiber stocks, it is much much stiffer and harder to make contact with the barrel.

All this being said the whole "slide a dollar bill under the barrel" doesn't seam to be making since. Spoke with mcmillan and they don't seam to have an explanation for it either. I know the saying if the rifle shoots, don't mess with it. I agree with that, but that still doesn't make it right and could contribute to flyers.

Any Ideas? Any advise? Once again, the bedding is completely stress free and the pillars are in there tight.

 

[GH41]

Are you shooting off of bags or tripod?

 

[celltech]

Does it have a brake with up facing ports...pushing the barrel back down? What is the recoil impulse like? Is the front of the gun kicking up and then slamming back down? Maybe use your cell phone to take a high frame rate video and watch what it's doing...

 

[flyfisherman246]

Shooting for the most part prone, bipod, and rear bag. Shooting with a Rex silentium mg7 suppressor.

 

[Snuby642]

I used to have the same problem with a rem 700 sp.

It had a houge stock.

But I fixed it.

 

[Thud]

Open the stock some more.

 

[...]

your rifle shoots....leave it alone.

 

[seanh]

If the gun is sitting on the bipod and bag is if you're getting ready to shoot, can you push on the barrel with your thumb over the spot of contact and make it touch the stock with relative ease? Or, does it take a lot of effort to make contact?

I've seen quite a few stocks, including that melon, where the forearm under the weight of the rifle (or recoil) have a bit of flex.

 

[Greg Langelius *]

As a test (and not a solution) remove the action, and place washers on the action screws between stock and action. This will elevate the barreled action slightly and may be enough to resolve the vertical stringing and confirm the cause.

If this works, remove and rebed the action, using those washers as stand-off spacers while the resin cures. Remove the washers once cured. This might be better achieved with the help of a professional gunsmith, depending on your own skills and needs.

I'm NOT a gunsmith; but I do perform some home gunsmithing (on my own rifles, only). I've done the above fix twice on my own rifles when rebarelling/replacing a stock.

Greg

 

[flyfisherman246]

I think I kinda figured out the problem but still kinda weird. I’ve been playing with the amount of force it takes to squeeze the barrel and stock together on these htg’s as well as many Manners stocks. The carbon fiber stocks are way way stiffer. That being said, I don’t think the barrel is actually touching under recoil. If you slap the bottom of the stock near the end, it doesn’t take much to make contact. So I’m thinking bouncing around in the truck and putting it down on bipods hard is probably what’s causing it to show signs of contact. Just thought this was an interesting find.

 

[Mauser06]

Never understood the ole "squeeze the barrel and stock" test. Yes...some of that is stock flex. A lot of that is the barrel. If you have a poorly bedded recoil lug, you will likely see more flex in the barrel. Think about what's going on. The recoil lug is basically a fulcrum. Barrel length, barrel thickness and stuff hanging on the end all play role in how much barrel movement you'll get.




If could just be from banging around. But, I'd test it.


Coat the barrel in transfer color. Lipstick will work I'd coat the barrel with a light layer. Carefully put the gun back together and handle it gently....fire a couple shots.

Take it apart. If you have lipstick on the stock, it got there when you fired it.



The weight of the suppressor hanging on the end of the barrel will magnify the barrel flex.

 

[Snuby642]

It could move in the stock if not tight or bedded or the stock is flexing.

Same with an ar handgaurd flexing or the barrel moving in the reciver.

Show us a picture of you flexing a barrel please.

The weight of a suppressor or even a muzzle brake changes harmonics.

It doesn't sag like a noodle..