Velocities measured today with LabRadar chronograph using the P320 full size (4.7" barrel) and Carry (3.9" barrel) models. The averages are for 10 shots each. Ten shots is a small sample, but I was primarily interested in comparing the Speer Gold Dot Jacketed Hollow Point load with the Federal HST. I added in the Speer Law Man TMJ load because it was available.

Something to be aware of about Speer 357 SIG Gold Dots is that the loads and bullets have varied some over time. The load I fired was item 54234 that I purchased in the last couple of years, and which is the less common load that I believe was the original hotter version. More commonly encountered is the “limited penetration” version that I believe was developed at the request of the Federal Air Marshal Service. In my previous testing with SIG P226 and P229 pistols, the LP load ran 40-50 feet per second slower. The HST may be loaded to the lower velocities of the limited penetration Gold Dot, but that’s just speculation.

Full Size P320:
Speer 125 grain Gold Dot, item 54234 - 1463 fps
Federal 125 grain Tactical HST - 1418 fps
Speer 125 grain Law Man TMJ - 1401 fps

P320 “Carry” (3.9 inch barrel which is the same as the “Compact” model)
Speer 125 grain Gold Dot, item 54234 - 1393 fps*
Federal 125 grain Tactical HST - 1353 fps

* The Gold Dot string with the Carry pistol included one shot’s velocity of 1346 fps that opened the extreme spread to 83 fps, or much larger than the other four strings. If that one shot was discarded, the extreme spread would have been 47 fps, with an average of 1399 fps.

I thought I might want to switch to the HST load based on some YouTube reviews, but as a result of today’s test, I’ll stick with the Gold Dot and its somewhat higher velocities. At 1463 fps from the full size P320, that easily meets the often-inflated claims of 1450 fps from the 357 Magnum 125 grain loads.

And although I don’t anticipate shooting through barriers like windshield glass, I also like that the Gold Dot is a bonded bullet. The HST reportedly holds together well, but because of how the jacket grips the core through its mechanical design.

FWIW, the Speer was the load of choice for Texas Department of Public Safety (highway patrol, Rangers) before they switched from 357SIG to 9mm.

I've only ever carried a P226R in .357SIG and have always loaded it with the 125gr Gold Dots. Good stuff.