Friday, June 02, 2017

Speed Reading

Preparing for a writeup at Breach Bang Clear, I got in some chrono testing of Federal's latest addition to the HST line, the 130gr .38 Special +P loading intended for short-barreled revolvers (since that's about the only kind of .38 Special revolver that's even remotely mainstream anymore, let's face it, fellow wheelgun fans.)

While I was there, I also clocked two classic loads often recommended for snubby use, as well as a lesser-known .38 Special loading, the 147gr +P+ Hydra-Shok.

First up is the 158gr lead semi-wadcutter hollow point, loaded to +P pressures. This is pretty much the classic self-defense load in the .38 Special, the vaunted "FBI load". Out of a 2-inch tube, it loses some steam, though:
LO: 812.3
HI: 878.7
AV: 852.2
ES: 66.46
SD: 19.51
That adds up to 255 ft/lbs of muzzle energy, the most of the four rounds tested, if you're the sort of person who puts much stock in that kind of thing. When you start stuffing more powder in a .38 in serach of velocity, you rarely do much for consistency. This box of ammo is probably a dozen years old, from a time when Remington's QC was much better than it is now, and we still see a 66 fps spread between the fastest and slowest rounds in a ten-round string.

That's nothing compared to the results from Federal's 147gr +P+ Hydra-Shok, though...
LO: 770.4
HI: 891.5
AV: 847.3
ES: 121.1
SD: 36.38
...for an average of 234 ft/lbs of energy. The Hydra-Shoks are from my half of a case that I split with a friend back in 2003. They've been stored in a non-climate-controlled attic for the last nine years, seeing seasonal temperature swings of probably fifty degrees, but I think the culprit in the massive velocity spread is more likely to be a lot of slow-burning powder intended to maximize velocity out of service-size barrels. In a 2" gun, this can lead to wildly varying numbers as lots of the powder is still burning when the bullet leaves the muzzle.

I also had a box of Federal Gold Medal Match 148gr wadcutters that I'd apparently been saving for a rainy day since 2005, so I donated ten to science for the chronograph.
LO: 628.3
HI: 682.0
AV: 662.5
ES: 53.63
SD: 17.00
Slow-moving rounds with more consistency, but only 144 ft/lbs. A lot of very clueful people I know advocate them for self-defense loads in a snub-nosed revolver because they're soft-shooting, penetrate well, be perfectly frank...hollow-points tend not to expand well, or at all, at the sort of velocities you're likely to get out of a snub-nosed revolver.

Which brings us to the new 130gr +P Federal HST, which is a jacketed hollow point with a monstrous cavity, like the old trick of loading hollow-based wadcutters backwards in the case. How did it do, velocity-wise?
LO: 753.9
HI: 811.3
AV: 782.9
ES: 57.42
SD: 20.12
A hundred and seventy-seven foot pounds of muzzle energy doesn't strike me as a lot when you want to use some of that energy to deform a hollow point bullet. I'll also note that, despite being nominally a +P load, the 130gr projectiles were traveling noticeably slower than the heavier LSWC-HP or Hydra-Shoks, and the round was commensurately more pleasant to fire out of a 2" barrel. I'm assuming that a faster-burning powder was specified, by the fairly consistent velocities and reduced muzzle blast.

For the conclusions, including terminal ballistic testing and what not, stay tuned for a link to the Breach Bang Clear piece.

EDIT: The default bullet weight in the online calculator I use is 150 grains, and somehow I reported the 130gr HSTs as being 150gr bullets. This has been corrected in the text. My apologies. Thank you to Rich Grassi for catching the error; he let me know this morning, but correction had to wait until I got back to my laptop.