Wednesday, February 08, 2023

Bees: Now 40% Angrier

I've written before about seeing underwhelming performance from 5.7x28mm rounds. 

I have here next to my desk a green-tip SS198LF round that was dug out of a gel block. It had gone into bare gel, yawed through 180°, and come to rest about nine inches in; as deep as a fully expanded .380 JHP. Underwhelming.

There's a clear gel block out in the garage (or maybe it's the one sitting in the passenger seat of my car) that has an SS195LF projectile sitting in it about eight inches deep. It went through four layers of denim, flipped once end-for-end, and wound up literally right next to a Prvi Partizan .32 S&W Long 98gr lead round nose projectile, itself not a noted fight-stopper.

The problem these rounds have is that they are 27gr bullets, light-for-caliber, which is great when you're trying to squeeze every last FPS out of a P90 PDW barrel, but not so hot at lower pistol velocities. That 180° flip bleeds off a lot of velocity from the light alloy-core bullets.

For a long time, that was pretty much all the 5.7 ammo you could get, too, which really limited the chambering's usefulness as a defensive round.

Now though, the SS197SR load, with its 40gr Hornady V-Max projectile, is plentiful. I've clocked those at an average velocity of 1691fps out of an FN Five-SeveN, and that's one on the right of the photo. It went through four layers of denim, expanded, and was caught in the denim on the far side of a 16" clear gel* block. That's adequate penetration in anyone's book.

Heck, the simple lead-core 40gr American Eagle TMJ averaged nearly 1600fps from the FN pistol, and that projectile in the middle made it over fourteen inches into the gel, easily dug out from the far side with a pocket knife.

The new Gold Dot projectile has shown similar performance to the 40gr Hornady V-Max from what I've seen.

These are all big improvements over the earlier underpenetrating ultralights.

L to R: FN 27gr SS198LF JHP, American Eagle 40gr TMJ, FN SS197SR 40gr V-Max

*DISCLAIMER: Clear gel is not a substitute for properly calibrated ordnance gelatin. The differences in their characteristics tend to (broadly speaking) cause expanding rounds to under-expand and over penetrate. Similarly the yawing 27gr bullets might have eked out another inch or two of penetration in 10% ordnance gel...which would still have been underwhelming. There's no "correction factor" you can type in to make them correlate, and trying to read tea leaves from the cavity in Clear Gel borders on meaningless. But I don't know of any rounds that do terribly in clear gel that have sterling reputations in the real world, and the very best loadings tend to turn in fairly similar performances, while marginal loads become really marginal.