POI/Group sizes with different muzzle devices. Range test and pic.

Stevo

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Here's a pic from the range yesterday. I tested all 4 different brakes/comps/flash suppressors I own (NEA Hybrid, Heavy and Phoenix and Czech military) along with nothing on the muzzle. All the groups were 5 shot by the same shooter (me), from the same rest, the same ammo and at the same distance (25m). Both rifles had 4 MOA dot RDS and, as you can see, the aiming point was a piece of tape. Hook and albertacoyotecaller were there and can confirm the results.

The pictured groups are representative and mirror previous results and follow-up groups shot yesterday.

Observations:
My 858 T-2 shot tighter groups regardless of muzzle device than my CSA Carbine. It had small variations in POI with different devices and the group size varied by a small amount. The NEA Heavy brake consistently turned in the tightest groups on the 858.

My CSA Carbine will not shoot as tight groups as my 858. The only obvious difference while shooting is the significantly heavier trigger pull on the CSA. Maybe barrel harmonics or length is the reason? I don't have the technical knowledge to figure that out. The CSA also exhibited larger POI shifts than the 858. For some reason, the CSA does not like the NEA Heavy brake, at all. The exact opposite of the 858s results.

Conclusions:
The 858 shot practically equally well with any muzzle device and didn't suffer and significant POI or group size shifts. It did shoot best with the NEA Heavy brake.

The CSA experienced larger POI and group size shifts than the 858. The NEA Heavy brake did not produce satisfactory results on my carbine. NEA's Hybrid and Phoenix worked best out of the tested muzzle devices.

As always, your mileage may vary. From now on I think the Heavy will stay on my 858 and the Hybrid on my CSA.




IMG_1630aMedium.jpg
 
Nice results and interestng info.
Good to see I'm not the only hill-billy using green painters tape for targets!;)
 
awesome thanks for the results, i am looking forward to getting my newly acquired csa to the range with the dlask akm brake i put on it, fit and finish are excellent and it makes the gun look so badass! just hope it performs as well as it looks. I know the akm brakes were overcompensating on the longer barrelled cz's and pushing the barrel down, im just hoping with an 11.5 inch barrel it works better
 
I just got the NEA heavy brake. I can't screw it all the way down flush before it clicks and it has a little play - it wobbles maybe 1/2 a milimeter or thereabouts and feels loose. Is that normal and safe to shoot with?
 
I just got the NEA heavy brake. I can't screw it all the way down flush before it clicks and it has a little play - it wobbles maybe 1/2 a milimeter or thereabouts and feels loose. Is that normal and safe to shoot with?

Someone at my range showed me a little trick to tighten up the muzzle brake on my CSA carbine by putting teflon plumbing tape on the threads of the barrel first. This eliminates all of the play. I was also told that the little bit of play on the muzzle break would change the POI of my shots because the gas it venting a little different every time which makes sense to me.
 
If you do some rapid, I'll bet the teflon tape could melt/smoke...but if you just take your time and let it cool, it would likely help group size by eliminating vibrations between the device and the barrel threads.
 
If you do some rapid, I'll bet the teflon tape could melt/smoke...but if you just take your time and let it cool, it would likely help group size by eliminating vibrations between the device and the barrel threads.

I thought the same thing but it actually holds up very well. Like you said though, I'm not doing rapid fire and going through 500+ rounds during my range visits. A couple hundred though, NO PROBLEM!;)
 
I have the Czech brake for my 858-2, and had the same problem with it wobbling around a bit. The first time I used it, the groups were all over the place, so I took it off, and everything was back to normal. I tried shimming it up with some paper just to see if I could get a couple groups off to see if that was the problem, but it didn't last. I figured it needed about a 15-20 thou shim to make it just snug down, but I think I'll go grab some of that teflon tape now. Thanks for the suggestion guys.
 
I just got the NEA heavy brake. I can't screw it all the way down flush before it clicks and it has a little play - it wobbles maybe 1/2 a milimeter or thereabouts and feels loose. Is that normal and safe to shoot with?


It is safe to use as is. Mine was like that and I have thousands of rounds down range with it.

It bugged me enough finally that I needed to fix it(OCD not function). Get a fine flat metal file and file the end of the brake that butts up against the front sight tower. Remove very small amounts at a time and test fit often. You will be able to get it so the plunger locks into the break when it is tight against the sight tower.

No more wiggle and a great, tight fit.

Shawn
 
It is safe to use as is. Mine was like that and I have thousands of rounds down range with it.

It bugged me enough finally that I needed to fix it(OCD not function). Get a fine flat metal file and file the end of the brake that butts up against the front sight tower. Remove very small amounts at a time and test fit often. You will be able to get it so the plunger locks into the break when it is tight against the sight tower.

No more wiggle and a great, tight fit.

Shawn

I think this might be for me. Thanks everyone for the comments and ideas.
 
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