.357 Sig reload numbers

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.

I had an opportunity yesterday to run some .357 Sig loads the other chronograph and here’s what I came up with.

Firearm: Glock 32, factory 4” barrel
Bullet: 125 grain Montana Gold JHP
O.A.L.: 1.135”
Brass: mixed brass trimmed to length, run thru Lee bulge buster and sized with Hornady dies.
Primer: CCI 500
OAT: 82 degrees
Elevation: 978 ASL

Longshot (Hodgdon website)
8.8 grains
1366
1368
1410
1387
1374

9.3 grains (max load listed) best grouping
1422
1406
1428
1399
1444

BE-86 (Alliant website)
7.7 grains
1283
1297
1293
1300
1307

8.2 grains (max load listed)
1341
1363
1352
1346
1344

AA9 (Lyman 49th shows 13 gr max and Speer 13th edition shows 14.6). The 13 gr lad previous shot showed good grouping so I thought I’d try Speers listing (hence the banner above)
13.5 grains
1435
1427
1409
1406
1412

14 grains
1486
1498
1483
1493
1501

I had no flattened primers on the 14 grain load but did have 1 case rupture. Recommend not going above 13.5 if you use the Speer manual.


Also, I shot some factory ammo thru the chronograph while I was out there and the Speer 125 gr Gold Dot LE ammo averaged 1280 FPS and the Federal LE 125 gr HST averaged 1350 FPS.

Hope this helps anyone loading 357 Sig. Again I’d not recommend going up to Speer 13th edition max load of 14.6 grains.

fxvr5 said:

Technically you have a split case.

The term 'ruptured' is usually used to a case blowout at/near the head.

Split and ruptured case can be cause by either bad brass or excess pressure, but split brass can occur with normal pressure due to bad brass and ruptured cases are often due to excess pressure.

Click to expand...

Yes you are correct.

Paul Toms said:

Longshot is pretty amazing, isn't it?!

Click to expand...

I was surprised at its performance. I actually love it in 9mm and .40 and plan on working with it a little more in the .357 Sig

I ordered some Underwood 125 gr GD HP yesterday. In the meantime I’m working up some 800x. If it groups good I’ll run them thru the chronograph when I get to the outdoor range.

Here’s what 9.5 and 10 grains of 800x looks like before bullet insertion.


And 13 grains of AA9