All data points are 5-round averages +/- STD fired at 80-85F and 30-35 mmHg BP.
1) Hornady .223 55 grain TAP GMX from 16" Steyr AUG (1:9): 2924 +/- 12 fps.
2) Hornady 5.56 NATO TAP GMX from 16" Steyr AUG (1:9): 3159 +/- 13 fps.
3) Hornady 5.56 NATO TAP GMX from 16" X95 (1:7): 3201 +/- 22 fps.
4) Hornady 5.56 NATO TAP SBR 75 grain from 10.5" LMT MRP (1:7): 2169 +/- 7 fps.
5) Hornady 5.56 NATO TAP T2 from 10.5" LMT MRP (1:7): 2423 +/- 19 fps.
6) Hornady .308 TAP 168 grain AMAX from 20" LWRCI REPR (1:10): 2531 +/- 28 fps.
7) Federal .308 168 grain GMM from 22" GAP HRT (1:11.25): 2669 +/- 21 fps (2693 +/- 7 suppressed with SOCOM-2)
8) Federal 300 WinMag 190 grain SMK from 24" AI AXMC (1:10): 2963 +/- 13 fps.
9) Winchester 5.56 NATO Ranger 64 grain RA556B 16" X95 (1:7): 2915 +/- 10 fps.
10) Winchester 5.56 NATO Ranger 64 grain RA556B 10.5" LMT MRP (1:7): 2506 +/- 8 fps.
11) Winchester 5.56 NATO Ranger 64 grain RA556B 10.5" LMT MRP (1:7) and SF SOCOM Mini2 Suppressor: 2544 +/- 22 fps.
12) Black Hills 5.56 NATO 77 grain SOTM 18" Noveske SPR (1:7): 2772 +/-14 fps.
13) IWI Razor Core 5.56 NATO 77 gain SOTM 18" Noveske SPR (1:7): 2772 +/-13 fps.
14) Barnes VOR-TX .300BLK 110 grain TAC-TX 9" Sig MCX (1:5): 2123 +/- 14 fps.
Note the anemic velocity from the Hornady 75 grain TAP SBR. The .300blk launches 110 grain pills at the same speed despite having a 1.5" shorter barrel. Thus, I've stopped using the TAP SBR and will be sticking with the RA556B for all of my SBR needs since it reportedly expands down to 1600-1700 fps. Also, note that the IWI Razor Core has essentially identical velocity to the much more expensive Black Hills load. My accuracy testing reveals the IWI load to approach the Black Hills load. Bottom line, IWI is some good stuff at a fraction of the price.