So, the other day I decided it was time to go ahead and rotate out the carry ammunition in my heater. I went to the ammo stash and grabbed the partial box of Winchester Ranger-T 127gr +P+ so I could refill the magazine and started to head for the door when I had an idea.
The M&P 357 also had a full magazine, left over from when I carried it last October, of Winchester Ranger-T 125gr ammo. I could take the chrono to the range and compare the two velocities out my own guns, because I'm all nerdy like that. Would .357SIG really be that much faster than the hot nine? Or was it just 9mm +P++, like some people (including me) kept insisting?
I got to the range, set up the chronograph in one of the pistol bays, and drew my pistol. I checked the headstamp on the top round in the mag, just to double-check: Yup, it said "+P+" right on it. Aiming through the skyscreens eight feet away, I cranked off a slow string of ten shots, then cleared the gun, set it down, and went to look at the numbers.
LO: 935
HI: 1220...
What. The. Hell?
That works out to an...
ES: 285
You could probably buy better consistency than that in a Peshawar back alley. Something was fishy...
I went back and checked the mag on the table. Sure enough, none of the other rounds in there were headstamped +P+. Some time during last winter, I had apparently put a magazine full of RA9T 147gr ammo in the gun, just by swapping the magazines and without changing the chambered round. Then, when I cleared the gun for the last Indy 1500, I reloaded by rotating the chambered round to the top of the mag, so that when I dropped the mag to check, I saw the expected 127gr +P+ round on top of the stack.
I clanged steel with the rest of the magazine and then loaded it with ten rounds of actual RA9TA +P+ from the box I'd brought.
LO: 1190
HI: 1230
AV: 1206
ES: 39.34
SD: 11.13
Okay, that was more like what I'd been expecting.
Winchester claims 1250 at the muzzle out of a four inch test barrel; 1206 at eight feet out of a real gun falls into "close enough for government work", and with a pretty impressive level of consistency, too.
Now for the .357SIG...
FWIW, I don't think the M&P 357 is that much trickier to shoot than +P-type street loads in the nine. It's louder, and chucks the brass halfway to Ohio (at least comparatively; it's no CZ-52, whose ejected brass is moving fast enough to make major) but the difference in splits isn't noticeable without a timer.
The tale of the tape for the .357SIG was:
LO: 1314
HI: 1394
AV: 1350
ES: 79.63
SD: 24.18
So, the velocity is spot on what Winchester claimed it would be, and close to 150fps faster than the nine. Is it worth it? I mean, it's harder to find, more expensive to shoot, holds two fewer BBs in the tank, and there's always that picture to bear in mind:
There was a time when I absolutely bought the death ray hype. Other than that P228 I used back in the early '90s for purse carry because I didn't trust a Glock in there, and my romance with the P7M8 back at the turn of the Millennium, I never carried a nine until I bought the M&P three years ago. I was all about .40 and 10mm and .357SIG, and then from '03 until just recently it was all .45ACP, all the time...
I dunno.
Anyway, I put the .357 back in the range bag, reloaded the M&P 9 with fresh BBs, holstered it up, and drove home.
.