Ballistic gelatin performance of selected 6.8SPC and .300BLK rounds

All information on this page provided by Doctor Gary Roberts

  Doctor Roberts recently tested some of the newer supersonic loads available in 6.8SPC and .300BLK. All shots below are from a 16" rifle at 10 feet.

XM68GD

6.8 mm Federal 90 gr Gold Dot JSP at 2604 f/s

PenetrationRecovered DiameterRecovered LengthRecovered Weight
Ballistic Gelatin12.3"0.62"0.26"83.6gr
Auto Glass13.0"
0.54"0.22"75.0gr


Shot into BG (above) and AG (below)


6.8 mm SSA 85 gr TSX OTM at 3024 f/s

PenetrationRecovered DiameterRecovered LengthRecovered Weight
Ballistic Gelatin18.5"0.56"0.41"85.3gr
Auto Glass17.0"0.58"0.39"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

PenetrationRecovered DiameterRecovered LengthRecovered Weight
Ballistic Gelatin16.0"0.48"0.47"83.5"
Auto Glass18.5"0.48"0.41"78.1"


Shot into BG (above) and AG (below)



6.8 mm Remington 115 gr FMJ at 2436fps

PenetrationRecovered DiameterRecovered LengthRecovered Weight
Ballistic Gelatin15+"0.40x0.15"1.09"96.3gr



.300 BLK Rem 110 gr TTSX at 2250 f/s

PenetrationRecovered DiameterRecovered LengthRecovered Weight
Ballistic Gelatin20+"0.54"0.50"107.6gr
Auto Glass17.0"0.58"0.22"65.4gr


Shot into BG (above) and AG (below)


.300 BLK Rem 125 gr SMK OTM at 2236 f/s

Ballistic gelatin performance: Pen=20+", projectile not recovered




.300 BLK Rem UMC 115 gr FMJ/CTFB at 2242 f/s

PenetrationRecovered DiameterRecovered LengthRecovered Weight
Ballistic Gelatin20+"0.30"1.14"112.6gr


bilobed yaw cycle with curvature and no hyper-expansion/fragmentation, very much like the 5.45x39mm M74/5N7 FMJ


Interestingly, the .300 BLK Rem UMC 115 gr FMJ/CTFB offers the longest single yaw cycle that we have ever seen.

Summary

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.