AR15 Performance 16″ Barrel w/ mid-length gas
Lewis Machine & Tool Enhanced Bolt
Model1 Sales enhanced firing pin : See below for chrono results and other information…
I performed a cursory function test for three different commercial loadings using the Casio ZR-100 camera and the Shooting Chrony Alpha chronometer. All video clips were filmed at 1,000 frames per second.
Prvi Partizan 123 gr. Soft Point Round Nose – 2440 fps, 2442 fps, 2497 fps, 2451 fps, 2469 fps. (Note: This ammunition is MALIGNED by the internet community and I purchased it almost entirely out of panic in January of 2013. I was fully expecting failure to feed every time, however, it actually functioned very nicely; I experienced zero failures. My sample size was very limited (fifteen rounds), however, so I reserve the right to change my mind in the future – but this stuff does not appear to be as bad as ARFCOM led me to believe.)
Wolf 154 gr. Soft Point – 2124 fps, 2122 fps, 2150 fps, 2122 fps, 2148 fps. (Note: I had VERY high hopes for this ammunition, but I experienced a high rate of failure to fire with this ammunition. It could be that I simply have a bad batch, an old batch or maybe a Timney 4# trigger module just doesn’t have the lagniappe to pop comblock berdan primers, but the enhanced firing pin was leaving nice, deep dimples and the ammunition failed to go bang at a rate of about 25%. As you can see, some instances of short-stroking. Pretty disappointing. It will be very difficult for me to ever put much faith in these cartridges)
EDIT: July 9, 2013 – I now run this upper with a JP Fire Control System trigger using the duty spring kit. With the Timney 4# trigger, berdan primed ammunition would ignite about 70% of the time, which was unacceptable for hunting or home defense. With the JP trigger, I have had one misfire in 120 rounds; I’m willing to assume that was a bad primer.
Hornady 123 gr. SST – 2265 fps, 2250 fps, 2267 fps, 2271 fps, 2259 fps. (Note: This ammunition was clearly the most functional. I will purchase more when I see it. If you have a 7.62×39 AR15, so should you.)