Muzzle brake is opening up groups

[johnino]

I have a Rem Sendero 7mm Mag shooting 1/3 MOA. I decided to send it off and have a brake fitted. Since I got it back I've been shooting terribly. I took it off the other day and I was shooting great again. Put it back on and groups opened up to 4MOA. I'll try and load a pick of the spread and what the brake looks like. I wonder if it's been made to slim. Would that create this problem?

Target below POA was the lower star

 

[Ernie]

When you add anything to your muzzle, it changes your harmonics. You will need to do load development with your muzzle brake on.
If a competent gunsmith put on the brake, he will have opened it up enough to where your bullets are not hitting it.

 

[bigngreen]

Maybe it the picture but it looks like the muzzle is protruding way into the first baffle, that may not be good but its may just be the way the pic is.

 

[johnino]

Yes you're right. That never crossed my mind.

 

[johnino]

I didn't realise load development needed to be done again. I looked through magnification and projectiles don't appear to be touching. I'm not feeling any significant reduction in recoil either.
I've since learned the guys a backyard gunsmith probably self taught. Perhaps I just take the hit and move on. Get a real gunsmith to make one.

When you add anything to your muzzle, it changes your harmonics. You will need to do load development with your muzzle brake on.
If a competent gunsmith put on the brake, he will have opened it up enough to where your bullets are not hitting it.

 

[bigngreen]

Sometimes you have to tune up your load but you should not blow your group up, I've never seen one that far into the first baffle, you should definitely be noticing some recoil reduction, do you have calipers that you can measure the size of the through hole?

 

[johnino]

Yeah I'll measure them when I get home tonight and put it up here. Thanks for all your help so far. It's been doing my head in.

 

[FearNoWind]

Notice in this video (when he removes the brake from the muzzle) how far back the muzzle is from the first baffle.
In your place, I'd do what I could to get it fitted correctly.





https://www.google.com/search?q=muz...Ftiger1.info%2FEN%2FMuzzle-brake.html;640;480

 

[Trever]

Wonder if he made a mistake and had to shorten the brake and start over?

 

[IdahoCTD]

The threaded section of the brake is really short. It doesn't really appear to be threaded too long either so either the brake came with a really short threaded section or he screwed up timing it several times.

 

[BergerBoy]

Good God!! 4 MOA??!! I had a Grizzly Brake open up my groups on my Steyr from .5 to 1 MOA and I never got it to close up so I pulled it. But I have never heard of anything opening a group up to 4 MOA from 1/3. The brake looks great but I would have another Smith look at it.

 

[mountainman56]

There should be a noticeable difference in recoil with a good brake. Threads should not be visible in the first baffle. Perhaps he neglected to re-crown the barrel after cutting threads?? Can you upload a picture with the brake off?

 

[DocB]

There should be a noticeable difference in recoil with a good brake. Threads should not be visible in the first baffle. Perhaps he neglected to re-crown the barrel after cutting threads?? Can you upload a picture with the brake off?

+1 Roger all that. The crown appears to be gone and the barrel extending into the first baffle is going to negate the recoil reduction. He did do a nice job turning the brake to match the barrel though. Perhaps a smith could turn a threaded spacer / jam nut to position the brake correctly and to assist in timing the brake. Then work up your load again when it's all done. Just an idea. Good luck.

DocB

 

[FEENIX]

Threads should not be visible in the first baffle.

Agree!