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At least, I think they're interesting 
. So I have 2 different .223 uppers for my AR, one is a Rock River Varmint, 20" SS heavy barrel, rifle length gas, .223 Wylde chamber, 1:8 twist. The other is a brand new PSA, 16" nitrided A2 profile, mid length gas, 5.56 chamber, and 1:7 twist. I was curious what I'd see for real world velocity difference, so tried a couple different rounds in both guns past the chrono (Labradar). The loads were a Magtech factory load with a 62 gr. FMJ, and a hand load with a Hornady 55 gr. SPFB over 24.5 gr. of H335 and a Fed. GM205M primer. The Magtech came in pretty good, I went from 3050 FPS in the RRA to 2943 in the PSA, a loss of about 25 FPS/inch. This isn't a particularly accurate round in anything I've used it in, so I'm happy to almost be out of them, best I've ever gotten is 2+ MOA.
The hand load went from 2938 in the RRA to 2740 in the PSA, a loss of almost 50 FPS/in. I realize there are a whole lot of factors involved, but it was still a little surprising, especially considering how accurate this round is in both rifles, around 1 MOA, and I can maintain around 2 MOA with the PSA and a red dot (Sig Romeo7). And it carries well, too, once I figured out my hold with the red dot, I was making consecutive hits on a ~12 steel plate at ~350 yards. Considering I could barely see the damn plate, I'm calling that good.
Anyway, just thought I'd pass this along, these two loads did a nice job of encompassing the "rule of thumb" 25-50 FPS/inch of barrel loss or gain. Later.
Dave
. So I have 2 different .223 uppers for my AR, one is a Rock River Varmint, 20" SS heavy barrel, rifle length gas, .223 Wylde chamber, 1:8 twist. The other is a brand new PSA, 16" nitrided A2 profile, mid length gas, 5.56 chamber, and 1:7 twist. I was curious what I'd see for real world velocity difference, so tried a couple different rounds in both guns past the chrono (Labradar). The loads were a Magtech factory load with a 62 gr. FMJ, and a hand load with a Hornady 55 gr. SPFB over 24.5 gr. of H335 and a Fed. GM205M primer. The Magtech came in pretty good, I went from 3050 FPS in the RRA to 2943 in the PSA, a loss of about 25 FPS/inch. This isn't a particularly accurate round in anything I've used it in, so I'm happy to almost be out of them, best I've ever gotten is 2+ MOA.The hand load went from 2938 in the RRA to 2740 in the PSA, a loss of almost 50 FPS/in. I realize there are a whole lot of factors involved, but it was still a little surprising, especially considering how accurate this round is in both rifles, around 1 MOA, and I can maintain around 2 MOA with the PSA and a red dot (Sig Romeo7). And it carries well, too, once I figured out my hold with the red dot, I was making consecutive hits on a ~12 steel plate at ~350 yards. Considering I could barely see the damn plate, I'm calling that good
.Anyway, just thought I'd pass this along, these two loads did a nice job of encompassing the "rule of thumb" 25-50 FPS/inch of barrel loss or gain. Later.
Dave
