Originally Posted by
StraitR
A large, county level, local LE agency invited all manufacturers to a gel test for potentially changing their current duty load for 16" patrol carbines and 10.5" SWAT SBR's. Reps for Winchester, Speer, and Hornady were in attendance. All cartridges performed as expected in the 16" patrol guns, for better or worse.
There was also a local AR builder there, retired from the same agency, and he had convinced some of his old SWAT pals to test a 7" build he had. This was done after the formal testing. To his credit, it ran well, but each and every projectile used to run the same FBI protocol test failed in bare gel. Each yawed, and exited the fresh from a cooler, and calibrated, block. I can't remember which did which, as testing through a 7" barrel wasn't relevant (just interesting) to my purpose there, but some projectiles yawed completely and exited the rear of the block, the result of which is over-penetration. Others yawed to a degree and exited one side or another. Only a couple were tested through what was left of the auto-glass, none of which made it close to 14".
Keep in mind, this was one day, with one 7" gun, and one FBI trained individual facilitating the test, but it is consistent with the average outcome of projectiles not reaching the bottom of their velocity performance window. I've made it a point, and habit, of avoiding open and public discussion of specific performance results I've seen in testing, as it could be misconstrued. I'm only sharing this because ALL 5.56/.223 cartridges failed the same test from a 7" barrel, which seems relevant to the discussion here.