Muzzle brake causes MULTIPLE FEET off POI shift on sub moa rifle.

[Eludnu]

The details. High end AR-47, Warne single mount base mounting Vortex VHS 4307. Sub MOA at 100 yards. (At the end of the story) First shot at 50 yards, next county over. Dial in way right, way up. shoot. Not on paper. Multiple rounds later, scope was at max right, max up, and shooting over 1 foot low and at least 2 feet left.

The spotter in the group suggested the only possibility was the full forward venting muzzle brake. Removed, and reset scope to zero. 5 shots later, 3 rounds, one jagged hole at 100 yards.

I am still flabbergasted. Had a can been on the end, it could not have resulted in anything less than multiple baffle strikes and a side exit. How in the world can a muzzle brake be THAT BAD on POI?
Needless to say, now looking for a new muzzle brake.

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[Riot]

The details. High end AR-47, Warne single mount base mounting Vortex VHS 4307. Sub MOA at 100 yards. (At the end of the story) First shot at 50 yards, next county over. Dial in way right, way up. shoot. Not on paper. Multiple rounds later, scope was at max right, max up, and shooting over 1 foot low and at least 2 feet left.

The spotter in the group suggested the only possibility was the full forward venting muzzle brake. Removed, and reset scope to zero. 5 shots later, 3 rounds, one jagged hole at 100 yards.

I am still flabbergasted. Had a can been on the end, it could not have resulted in anything less than multiple baffle strikes and a side exit. How in the world can a muzzle brake be THAT BAD on POI?
Needless to say, now looking for a new muzzle brake.

Might not even by the muzzle break, itself...the threads might not have been cut straight. If the new muzzle break is still causing issues, leave it off...accessories (hand guards, bayonets, etc.) touching the barrel do funky things to bullets sometimes.

 

[Mark W.]

It can also be the same effect real hot loads have on a revolver with a very short barrel. If the powder is still burning as the bullet leaves the muzzle it is possible for the unrestrained pressure to "tip" the bullet a tiny bit as you can imagine this screws accuracy.

Your forward blasting break maybe doing something similar. Also check to see if there are any wear marks around the bore of the break. It may not even have to touch just allow an uneven pressure to escape causing the bullet to be "tipped"

 

[mjbskwim]

man that far off it seems it would be striking the brake.
When you did hit paper with the brake on,what did the holes look like?

 

[Velzey]

Boy that's an odd one! I to think the threads may not be square to the bore. What's the inside diameter of the break? It sounds like you may have contact!

 

[Riot]

Boy that's an odd one! I to think the threads may not be square to the bore. What's the inside diameter of the break? It sounds like you may have contact!

Contact with the muzzle break would be very apparent and I've only ever heard of a threading being cut wrong on custom cut jobs...I'm thinking, though, that for the bullet to be thrown off in a specific direction that either the threading isn't square, the break ports are just not evenly cut or the muzzle break is just lopsided.

Obviously the smartest way to go about this is to simply replace the break and to see if it still is throwing the bullets off...

However, you can also bring the target in a little closer than 100 yards and mess with the current break.

Unthread the muzzle break just a little bit (maybe like a quarter turn) then shoot at your target...repeat a few times (turning it a 1/4 turn each time)...if it throws the round off in a different direction, it's your muzzle break...if it holds- it's your thread.

*Caveat*

If for any reason you think that the bullets have -or will- make contact with the break, don't do the above...

 

[jbett98]

You could leave the brake on and rotate the firearm 45* to see what happens.

 

[Velzey]

I've seen misalignment on several factory barrels...Savage, Smith and Wesson, and a Remington. So it happens. It could be the smallest little nick.. Rotate is a good idea! Have you talked to RRA about it?

 

[solv3nt]

You could leave the brake on and rotate the firearm 45* to see what happens.

Gangster style is 90 degrees.

 

[Bon Sauvage]

I suggest that you start by closely looking at your brake. If the bullets are striking it I believe that you should see gilding metal contact on some part of the brake.

 

[Eludnu]

man that far off it seems it would be striking the brake.
When you did hit paper with the brake on,what did the holes look like?

Nice and round.
The spotter, took the brake home so I too am curious to take a closer look at it's exit.

 

[Eludnu]

Boy that's an odd one! I to think the threads may not be square to the bore. What's the inside diameter of the break? It sounds like you may have contact!

My buddy took the brake home as it was one his co-worker was interested in trading. (A fair trade might include a toothbrush with no bristles, or a wheelbarrow with one handle.)

I will get it back and run a very close inspection, including mic

 

[DizzyJ]

I too am curious as to whether or not it (the bullet) was hitting the brake.

 

[mjbskwim]

I'm guessing here,but if the hole in the target was perfect,then it is the way the ports are cut.
If it's hitting the brake,then that little 55gr pill would tumble
I guess we will find out soon

 

[Eludnu]

Correction to my previous comment. After two shots of not hitting paper with significant adjustment to the scope, I moved to dirt so we could witness impact more accurately. So, I have no idea if the holes on paper would have been clean, as I never hit paper with the brake on. Once we realized the scope was at max elevation and windage, we pulled the brake. A quick look did not show obvious strikes.

The clean holes thorough the paper where with the brake off. Sorry for the mistaken info.

 

[v0lcom13sn0w]

try a different brake? i use the surefire procomp with EXCELLENT results.

 

[mjbskwim]

Correction to my previous comment. After two shots of not hitting paper with significant adjustment to the scope, I moved to dirt so we could witness impact more accurately. So, I have no idea if the holes on paper would have been clean, as I never hit paper with the brake on. Once we realized the scope was at max elevation and windage, we pulled the brake. A quick look did not show obvious strikes.

The clean holes thorough the paper where with the brake off. Sorry for the mistaken info.

I just don't see how you expect us to help with government type info.
Oye vey
Yeah I would believe the FH would definitely show a hit or not
Never heard of the gas flow changing the POI like that though.
Is this a new product for the manufacturer? I'm sure they would like to know your results,too

 

[Eludnu]

I just don't see how you expect us to help with government type info.
Oye vey
Yeah I would believe the FH would definitely show a hit or not
Never heard of the gas flow changing the POI like that though.
Is this a new product for the manufacturer? I'm sure they would like to know your results,too

"Government type info" LOL. At least I offered an apology.
Some people. Shoot them with a new bullet, and they still complain.

I do not know yet what exactly caused the POI shift. Many of you have offered sound input into what the culprit could be, that I had not considered prior. Until I can narrow it down a bit more, I want to be careful about throwing the bus into reverse and driving over the brake manufacturer. No matter the outcome, it was one of those moments where all who witnessed it where set back a bit.

 

[308]

The muzzle brake is not causing the POI shift. The fact that the projectile is striking the muzzle brake prior to leaving the rifle is. I've been down this road a few times especially when a crush washer is used.

 

[308]

....and while I'm at it Once the bbl heats up you will be chasing your POI all over the target.