Reloading .357 Mag
The famous .357 Magnum, the original magnum pistol
cartridge, was introduced in 1935 by Smith & Wesson as the world's most
powerful handgun cartridge. For over 20 years it was simply known as "the
Magnum," as there was no other. Newer magnum cartridges eventually
surpassed it in power, but not in popularity or usefulness. The .357 remains
the best selling of all magnum handgun cartridges and among the top 10 best
selling handgun cartridges.Any .357 Magnum revolver can also shoot all .38 Special
ammunition. .38 Special +P loads make particularly good practice ammunition and
with 125 grain bullets shoot sufficiently flat for small game hunting.
.357 Magnum factory ballistics tables call for a muzzle
velocity of 1450 fps for the 125 grain JHP with 583 ft. lbs. of muzzle energy.
For the 140 grain JHP the MV is 1360 fps and the ME is 575 ft. lbs. For the 158
grain JHP the MV is 1235 fps and the ME is 535 ft. lbs. These figures are all
for a 4" revolver barrel.
I have been reloading the .357 Magnum since the middle
1960's. I have found Winchester W231 and Hodgdon HS-6 powders excellent for low
and medium velocity loads and H-110, W296 and Hercules 2400 powders excellent
for maximum loads with bullets weighing from 125-158 grains.
The various 125-129 grain bullets are the top choices for
personal defense against "bad guys", but have not provided top
accuracy in my .357 handguns. I have found the 140-146 grain bullets to be a
good all-around choice for use in the field and very accurate. The heavy
158-180 grain bullets are the ticket for many big game hunting applications and
for defense in the field (against large predators).
The Handgun Reloading section of the Speer Reloading
Manual Number 14 shows that 16.5 grains of 2400 powder will drive
their 125 grain bullets to a MV of 1335 fps, and 17.5 grains of 2400 will drive
the same bullets to a MV of 1409 fps.
The 140 grain bullet can be driven to a MV of 1005 fps by
8.8 grains of HS6 powder, or 1142 fps by 9.8 grains of HS-6. I have found these
to be useful practice and small game loads.
On the other hand, 16.2 grains of H110 powder will drive the
140 grain bullet to a MV of 1323 fps, and a maximum load of 17.2 grains of H110
will drive the same bullet to a MV of 1352 fps. These are good full power
For heavy loads, the Speer Reloading Manual shows
that 13.9 grains of H110 will drive their 158 grain bullets to a MV of 1151
fps, and 15.5 grains of H110 will drive those bullets to a MV of 1217 fps.
These Speer velocities were measured in a 6" S&W revolver barrel using
Speer cases and CCI primers.