Help- Accuracy & muzzle brake on 300 ultra

[slowbow]

I had a muzzle brake put on my 300 ultramag and now I couldn't hit a barn with it if I was shooting from the inside! I took it back to the gunsmith and showed him my before and after groups on paper (went from 1.25" @ 100 yds to 4+"). He checked the bullet clearance, said there shouldn't be any problem, and sent me back to the range.

I'm not very familiar with gunsmithing, etc (I primarily bowhunt), but I can shoot a rifle well ( a lot better than 4" @ 100 yds.), and I need advise on what to do about this rifle.

Any suggestions would be greatly appreciated.

Slowbow

 

[RLH]

i've never seen a muzzlebrake that altered accuaracy a lot. i would imagine it would change the zero, no matter what you do, but not that much. shouldn't be more than just resighting it in. the spread you mention seems quite extreme. are there any signs of the bullet touching the brake? like evidence of copper or anything in just one place? if he didn't get it on real straight, that might be it. other than that, i can't see where it should have a real adverse affect. they are real noisy. is the elevated sound causing a little flinch maybe? i'd go back to the range and try it again and be real careful to shoot as good as you can. if it's still bad, maybe have him take it off and try it again. don't touch the sights until you try several things. so you have a baseline to work with. is it a screw-on one where the end of the barrel is threaded or is it sweated on? it'd be hard to do, but maybe the last bit of the barrel was damaged somehow in the installation process. good luck.

 

[Boman]

I'm thinking the same as RLH. Did the smith recrown the barrel for you? Can you screw off the brake? If so take it off and shoot it and see what your group is like.. other than that the brake shouldn't affect it at all. Good luck

 

[hicountry]

these are all good ideas.i would say take it offand shoot it without for a while(if its a threaded screw on).also check the brake for copper.Brakes are alsoo way loud so it may have given ya a little flinch.also heard that certain things like that and throw of the barrel vibrations(also barrel bands).he may have damaged the muzzle.hope it gets better.
hicountry.