We recently tested some newer supersonic loadings in 6.8 mm and .300 BLK.
6.8 mm Federal 90 gr Gold Dot JSP at 2604 f/s
BG: Pen=12.3", RD=0.62", RL=0.26", RW=83.6gr
AG: Pen=13.0", RD= 0.54", RL=0.22", RW=75.0gr
Shot into BG above one through AG
6.8 mm SSA 85 gr TSX OTM at 3024 f/s
BG: Pen=18.5", RD=0.56", RL=0.41", RW=85.3gr
AG: Pen=17.0", RD= 0.58", RL=0.39", RW=65.4gr
Shot into BG depicted; AG wound profile not shown, but nearly identical
6.8 mm SSA 100 gr Accubond PT at 2680 f/s
BG: Pen=16.0", RD=0.48", RL=0.47", RW=83.5gr
AG: Pen=18.5", RD= 0.48", RL=0.41", RW=78.1gr
Shot into BG above one through AG
.300 BLK Rem 110 gr TTSX at 2250 f/s
BG: Pen=20+", RD=0.54", RL=0.50", RW=107.6gr
AG: Pen=17.0", RD= 0.58", RL=0.22", RW=65.4gr
Shot into BG above one through AG
.300 BLK Rem 125 gr SMK OTM at 2236 f/s
BG: Pen=20+", projectile not recovered
bilobed yaw cycle with curvature and no hyper-expansion/fragmentation, very much like the 5.45x39mm M74/5N7 FMJ
.300 BLK Rem UMC 115 gr FMJ/CTFB at 2242 f/s
BG: Pen=20+", RD=0.30", RL=1.14", RW=112.6gr
very long, broad single cycle yaw cycle with curvature and no hyper-expansion/fragmentation
Interestingly, the .300 BLK Rem UMC 115 gr FMJ/CTFB offers the longest single yaw cycle that we have ever seen.
Both 6.8 mm and .300 BLK are excellent cartridge choices for individuals and organizations requiring a caliber larger than .223, that functions reliably in an AR15. At this time, the major .300 BLK loadings all penetrate deeper than the 12-18" ideal range for LE use; in contrast there are multiple 6.8 mm loads which currently meet this criteria, along with offering acceptable intermediate barrier capability.
Top row: .300 BLK Rem 110 gr TTSX; below the dime are the 6.8mm SSA 85 gr TSX, Federal 90 gr GD JSP, and SSA 100 gr Accubond PT. Right column in BG, left column through automobile windshields.
While the .300 BLK TTSX is a superb loading for military and hunting purposes, penetration is a bit deeper than ideal for LE use. An LE optimized .300 BLK loading engineered with proper feed profile, 12-18" penetration depth, that is blind to barriers will be a great addition.
.300 BLK Rem 110 gr TTSX vs. .300 BLK Rem UMC 115 gr FMJ/CTFB in BG