Virginia Gun Owners Forum - VGOF

I thought I'd share an experience I had with muzzle brakes.

A little while back, I threaded a rifle barrel for a muzzle brake, intended for use with a suppressor. I indicated the barrel on my lathe, using an insert in the muzzle to ensure the threads were cut concentric to the bore. The threads were cut to the muzzle brake manufacturer's specification, the critical dimension is the thread depth, at .600" (+/- .010"). Operation complete, brake installed, customer happy.

Next time I talk with the customer I'm told he suffered a very mild baffle strike. Not good. Further information reveals that a rifle capable of 2 MOA at 300 yards is now shooting 8" patterns at 100 yards. Not good. My suspicion is unstable bullet.

I get the rifle in the shop and confirm the threads are good, shoulder is good, muzzle crown is good and muzzle is flat. The rifle, without the brake, shoots a stabilized bullet and a test group of .750" at 50 yards (I have a very small test range). Install the muzzle brake and it confirms an unstable bullet. Looking at the carbon residue in the brake it appears there is about .300" of exposed thread and I noticed about a .700" total gap between the muzzle and first baffle in the brake. What was happening is the air being pushed out of the barrel by the bullet (precursor wave) was being disturbed by the exposed threads and other irregularities in that .700" gap, causing turbulence that unstabilized the bullet.

My solution was to make a plug that threaded into the brake to take up that gap and eliminate the turbulence. After a bit of fitting I installed the brake and fired a test shot which revealed a stabilized bullet. A 50 yard group of .230" confirmed my solution.

In the future, any threads I cut for muzzle devices will be cut based off measurements from the device to ensure no irregularities exist to cause turbulent air. I hope that any practicing gunsmiths can benefit from this info.

Pretty cool.
Do you think it worth the time and cost for bedding a Rem 700 with the crappy factory stock? Stock is touching the barrel and it shoots all over the place.

Kelu, I would most likely just pick up a Boyds Custom stock, they are quite reasonable, and after installing the action in that you need to bed it, you at least have a stock that one you like, and two is very well made. Just my 2 cents. I have ordered one of their stocks and the ship time was dead on, and the stock was top notch. The project that went into that stock is a full custom air rifle, so I had a very small bit of inlay due to a non factory stabilizing band, but the fit before the band was like a glove with nothing touching to interfere with the barrel, or air tube for that matter.

Casey

I wish to say thank you. I just threaded the barrel on my VEPR .308. While the barrel threads are longer than the brake's threads are deep, this is valuable information. I will ensure the brake is as bottomed out as I can get. Also, I have to say thank you to GoGun for producing a version of their .308 brake with 14x1LH threads. Gets me a proper brake for the round without using a thread adapter.

Kelu, it depends on what type of accuracy you're looking for and how much time/money you want to invest. The Remington stock is certainly adequate for hunting as is. The barrel should be factory free floated but the stock may need a bit of reinforcement to ensure it does not warp upwards as the barrel heats up (my Mossberg ATR does this). The action needs to be glass bedded (pillar bedded will give even more rigidity). My opinion, for the cost of a Boyds custom stock, you could have your Remington stock bedded and reinforced. The Boyds stock would still need glass bedding.

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I would say under 2 moa. It's not a sniper rifle, but it should be capable of at least that.
The factory stock is that hollow flimsy plastic. I like it that's light.
You think you can reinforce it and pillar bed it? Can you throw an estimate? PM would be fine. I like to support small local companies.
Normally I would tinker myself, but lately I am pretty busy, and you're not too far from me.

don't want to steal money out of a gunsmiths pocket, but when I can get a magpull hunter stock for $250ish on my door step, I don't think I'd put $1 into 'fixing' the factory stock.

My estimate is a pillar and bed job is going to be at least 1/2 the cost of the magpull stock, and might be 2/3's the cost if you had to pay shipping both ways. And while it should certainly help, its not a 100% sure way to fix what problems the rifle might have.

The magpul might not be your cup of tea, but its an example of quality entry level 'chassis' systems that are available for not a ton of cash, and they are a simple DIY swap.

a new stock, a better trigger, and who knows you might be better of selling it as-is, and going out and buying a Tikia.

Any stock made for any rifle can be a "drop in" fit and very well might improve accuracy. To get the maximum accuracy from any rifle you need to minimize any variables. The variables that pertain to the stock are contact with the barrel, chamber/action/lug contact and action screw tension.

Barrel contact: As wood stocks absorb moisture and synthetics heat up they can warp, putting pressure on the barrel. The more expensive synthetics are rigid enough to prevent the heat warpath.

Chamber/action/lug contact: These areas need consistent contact to prevent the barreled action from slipping in the stock. The recoil lug needs a flat, rigid surface to rest against to prevent slippage.

Action Screws: Over time, wood and synthetic stocks can be compacted by tightening and retightening the action screws. This allows up and down movement of the action. Pillar bedding provides aluminum pillars for the action screws to pull against, preventing the slow compaction of the stock and allowing consistent torque on the action screws.

Even the MagPul Hunter stock can benefit from a gunsmith practising his trade. But, it depends on what the shooter wants. My Mossberg ATR is more than capable of sub MOA groups but the stock will begin to warp upwards on the 3rd shot. This doesn't matter to me as it is my hunting rifle and I only take one shot. If I were to dual purpose this rifle and use it for competition or varmints I would seriously consider bedding the action and reinforcing the forearm so that it does not warp.

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RE: Action and barrel bedding
I took a slightly different route with my CZ-452 .22 target rifle.
I Pillar bedded the action by using brass threaded nipples from the lighting dept. of Lowes.
It the process I raised it enough to fully float the barrel forward of the front post so that a playing card would fit between the barrel and stock for the full length of the barrel.
That turned a $250 rifle into a pretty good benchrest gun.

jdonovan, right as always.
Thank you for sharing your knowledge.