Ballistic gelatin testing of select 6.5 Grendel loadings was performed this past Monday, May 8, 2006, and I've finally got my hands on the results. I've waited two years for this! CentCom tested one 6.5 Grendel load in August 2004, but, apparently, didn't feel the need to release the results for civilian or commercial use.
Alexander Arms contracted this latest round of gel tests from Speer Law Enforcement representatives in order to have these tests serve as an experimental "control" for ballistics gelatin tests performed by other entities.
Speer performed these tests according to the standard F.B.I. Protocols, as well as their standard in-house procedures. They use 6 x 6 x 16" blocks of ten percent ballistic gelatin, calibrated with a BB. It is interesting to note that Speer uses green dye instead of red to better delineate the temporary and permanent cavities; we conjecture it's for "politically correct" considerations.
Alexander Arms tested four loads: (1) 120 Norma FMJ, (2) 120 Sierra MatchKing (SMK), (3) prototype 123 SMK, and (4) 90 Speer TNT. All tests were performed using production Alexander Arms Tactical 14.5 and Tactical 16 M4-style carbines at ranges of 50 and 100 yards. Here is a summary of the results:
120 Norma FMJThe 120 Norma FMJ, above, penetrated 16.5" before veering out the side of the block and impacting the support frame. No fragmentation was evident, but the slug is believed to have tumbled at about the 7" mark, with the maximum permanent cavity at the 11" mark. Lesions of more than 6" were created on the top and bottom block surfaces. The Alexander Arms Tactical 14.5 was used in the three 120 Norma FMJ photos shown here. Range: 50 yards. Impact velocity: 2405 fps.
Another shot of the 120 Norma FMJ.
Close-up of 120 Norma FMJ.
120 Sierra MatchKingThe 120 Sierra MatchKing penetrated 3.25" before yawing and fragmenting. The Alexander Arms Tactical 16 carbine was used in the three 120 SMK photos shown here. Range: 100 yards. Impact velocity: 2383 fps. (Velocity from 24" test barrel was 2660 fps @ 49,800 psi.)
Maximum penetration of the 120 SMK was 19.5", maximum permanent cavity diameter was more than 6" with lesions running to block exterior surfaces. Depth to the maximum permanent cavity was 7.5". Bullet fragmented, with seven large pieces visible within the block. Jacket sections came to rest at 11.75" and 16.25", and the bullet core at 19.5".
Close-up of 120 SMK penetration neck before yaw.
123 Sierra MatchKing PrototypeThe prototype 123 SMK penetrated 2" before yawing and fragmenting. (The 123 SMK is not currently a Sierra catalog offering.) The Alexander Arms Tactical 14.5 carbine was used in the three 123 SMK photos shown here. Range: 50 yards. Impact velocity: 2385 fps. (Velocity from 24" test barrel was 2650 fps @ 49,500 psi.)
Maximum penetration of the 123 SMK was 16.2", maximum permanent cavity diameter was more than 6" with lesions running to block exterior surfaces. Depth to the maximum permanent cavity was 7". Bullet fragmented into multiple small fragments with jacket pieces visible at 11" and 13". Small core fragment was visible at maximum depth of 16.2"
Close-up of 123 SMK penetration neck before yaw.
90 Speer TNTThe 90 Speer TNT performed as expected for a varmint bullet.
Auto GlassEntry hole of the 120 SMK through auto glass.
Impact of 120 SMK into ballistic gelatin after passing through auto glass.
SummaryThese tests demonstrate the flexibility of the 6.5 Grendel cartridge in tactical scenarios. Each loading is a tool designed to perform a certain job. If you need penetration, use the 120 Norma FMJ. If you need a general-purpose tactical OTM with decent penetration of intermediate barriers yet with very good fragmentation, use the 120 SMK. If you want a long-range bullet that shoots like the 123 Lapua Scenar yet exhibits very early and explosive fragmentation, call for the 123 SMK.
It's interesting that the 123 SMK, a bullet that rivals the 123 Lapua Scenar with its .547 BC, also proved to be the most violently fragmenting round of those tested (well, not counting the TNT). We had been led to believe that bullets that perform extremely well at long range would perform poorly at CQB in MOUT. However, testing now shows that the 123 SMK provides wicked fragmentation at CQB ranges with twice the lead mass of 5.56 NATO, as well as shooting flatter and drifting less than 7.62 NATO out to 1000 yards. This capability in one loading truly makes the 6.5 Grendel a unique tool in the AR15/M16/M4 tactical toolbox.
I will update this report as more data comes in. It's unfortunate that the Wolf 6.5 Grendel ammunition did not arrive in time to test, so that will also have to wait until later.
John