JP Rifles/Delta P Design Tactical Compensator Review
It occurs to me that my review of Warren's brake, which I posted on his group buy thread, might fit in here, too:
Test bed: SAI Super Match, Douglas SS barrel, USGI Synthetic stock opened up for rear lug.
Visually, the brake is a work of art. Finish is perfect, overall look is very intimidating. GI6 Installation was easy. Splines were snug in the barrel grooves but not tight enough to require a rubber mallet. No rotation of the brake is possible because of the snug spline fit but since the splines are round rather than elongated as on typical brakes or FS's, up-down and/or side to side movement is still possible. On my sample, the castle nut could only be inserted from one side. The back section of the brake where the muzzle inserts (i.e., forward of the window the castle nut fits into) has a shallow collar with a central depression. The collar is slightly larger in diameter than the muzzle on the Douglas barrel so some play is possible, raising some concerns that alignment could shift with use since the round splines can't contribute to overall alignment. Tests with an SAI alignment gauge show that with the brake pushed to the right on my barrel, the gauge comes pretty close to the front hole in the brake (but YMWV). The tip of the castle nut set screw is broader than the standard set screw so alignment of any given castle nut notch becomes more critical. I found the easiest method was to take the set screw out, turn the rifle over, and look through the hole to align the notch, then put the screw back in.
At the range, a bipod and rear bag were used from a bench with a 6-24X scope @ 100 yds. First, there was no indication of misalignment whatever. Second, there was a pronounced shift in POI from the zero used with the NM FS installed by SAI (4" down and 3" right). Third, there was practically no recoil, certainly less than an AR, which is saying something. Fourth, and this was quite a surprise, it was relatively quiet! The USCG brake tends to be very loud, and this seemed even quieter than the NM FS that preceded it. Finally, accuracy seemed to improve. While the fouling shots with PPU 145 gr FMJ didn't look all that great (about 3" for ten rounds), Radway Green delivered a bit over 2" for seven rounds, and Federal Gold Medal Match 168 gr consistently made ragged holes with multiple rounds (e.g. 4 rounds clustered in 1/4" with the fifth about an inch away which was no doubt my fault). That ammo was factory seconds due to accuracy, so I expect Federal first quality will be capable of much better results than this shooter can deliver. Perhaps most surprising was Sellier & Bellot 147 gr FMJ, which put 5 rounds in a 1" square.
The Super Match didn't start to deliver its potential until SAI fixed the wandering op rod guide and then I put it in the USGI Synthetic. But today's results are the best it's ever delivered and I think at least part of that is due to 82nd ABN's brake! This is definitely a keeper!
Thank you Warren! GI2