Updated pics. Again, no appologies for my ability as a shooter. Running a magnified optic and bipod and trying for the best possible accuracy is very new to me as I’m generally content if I can hit a 6" steel at whatever range I’m engaging from and do so as quickly as I can. I certainly didn’t take the time I should to try for groups in this test. I think you’ll be able to tell the potential of each ammo type, and pick out the shooter errors. Each group was 10 shots. With all but the Barnaul, I’d call anything outside the 10-ring a flier, and with the Black Hills I’d call anything outside a 1" circle a flier (shooter error).
Since people keep asking…
I fired 30 shots of XM193 to get the scope on paper (scope is turned sideways, took me a couple of tries to figure out how to adjust for that), and then 10 shots of Black Hills to get zeroed. After that I shot the suppressed groups, BH & W first, then reload (I only had two 20-round mags with me) & shoot XM & Prvi, then reload and shoot B. I then let the gun cool enough to remove the suppressor, and fired 10 rounds of XM to heat the barrel back up, then followed the same shoot/load schedule above. Without a temp sensor I guesstimate that the barrel was kept as close to a constant temp as I could.
After all of this, my conclusion is that the muzzle brake mount definitely makes for less of a POI shift than the A2.
This was my first time shooting the gun with the brake mounted but without the can. The brake is LOUD, especially so with the XM193, even with my Sordins on. If I was going to be shooting just milspec ammo with only the brake on I would double-up on plugs & muffs. It was borderline painful to shoot (and probably affected the unsuppressed XM groups because of it to some extent). Because of this, I found an interesting conundrum; if you want to shoot the gun both suppressed and unsuppressed and see the least amount of POI shift, you need the brake, but shooting unsuppressed with the brake can be borderline intolerable, making the A2 a much better choice.
For me, I only ever intend to shoot this particular rifle suppressed. That’s in fact the whole purpose for this particular rifle. In which case it really doesn’t matter which mount I use, except to say that the brake allegedly both better protects the baffles and provides better sound suppression than the A2 mount. The other school of thought would be that even in my previous test the shift was acceptable for the range at which an 11.5" barrel AR would be effective, so the A2 is certainly serviceable if the user needs to have both suppressed and unsuppressed capability. For me, I’ll keep using the brake on this gun since it stays suppressed, and I’ve mounted the A2 on my other 6933 just in case I ever want to put the can on it. I’d like to try the 3-prong mount I see on ADCO’s site now, but not bad enough to pay for one.
It does bear mentioning that the A2 mount that I received with my can sells for $75, and the brake mount sells for $185. I am unsure if this savings was reflected in the price I paid for the can or not, but it’s somewhat of a moot point now as Ops at least sent me out a free muzzle break mount after seeing the first post in this thread.
Thanks again to Ops for all the help, and hopefully the new results are more in line with what they would expect to see.
The ammo used
The gun (with suppressor and without)
Suppressed groups
Unsupressed groups
