muzzle brake v's accuracy


Well-Known Member
Jun 6, 2007
Gday to all

Was at the range the other day and was working on a load for my 338 lp and could not get better than 1 moa groups at 100 metres. Its a custom made rifle so the accuracy should atleast be .5 moa and better. So i decided to take the brake off to see what the result would be and my first 3 shot group was .25 moa.
Is this a fault of the gunsmith that made the rifle or is that what happens with muzzle brakes?

I've seen brakes mess up a rifles accuracy and the reasons were this.

1. Poor brake design, example shrewd varmit brake with holes only on the top 180 degrees, produced same results your' describing.

2. Not enough clearance on the baffle holes, or unconcentric clearance.
I have seen the clearance holes "close up" over use. The gas cutting on a baffle actually can create a bur on the leading edge of the baffle, this bur then is pushed or displaced into the clearance hole. Causing a constriction, and unconsentric hole at the baffles leading edge. (if this was your problem typically the rifle shoots great but over time and use the accuracy deteriates.)
Concentricity can also be the problem if the brake was installed unconcentric with the bore, due to a poor set-up on instal.

Good brakes should have no effect on accuracy other than to allow you to shoot better.
There is another thing....think of your brake as a tuner...just not adjustible. You are effectivly hanging a weight out past the effective end of the bbl....just like a tuner. My 1000 yard comp guns needed two differant with the break, and one without. I shot the same gun in both lite gun and heavy gun (HG rules do not let you use a brake) class. I found that I could get my gun to shoot better if I tweaked the load for the gun w/o the brake. On the other would not shoot quite as good if I shot the unbraked loads with the brake installed.

Try a few more differant loads. If you are getting no better that 1 MOA, try WAY different loads.

More likely than not Cowboy is right, because going from no better that 1 moa down to 1/4 moa (I assume you did 1/4 moa more than once??????) is quit a change. But, on the other hand ,I have seen 1 click on a tuner make a world of differance on target.

Just my .02....based on my comp guess is that a hunting gun could do the same thing.
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