The .38 Special and .357 Magnum share the same bullet diameter, making them uniquely versatile for the cast bullet shooter. One set of molds and sizing dies covers both cartridges. Whether you shoot revolvers, lever-action rifles, or competition cowboy action, cast bullets are the most economical and practical choice for these classic American cartridges.
The .357 Magnum was designed as a lengthened, high-pressure version of the .38 Special. Both use .357"–.358" diameter bullets. A .358" cast bullet sized properly works in .38 Special target loads at 700 fps and .357 Magnum hunting loads at 1,400 fps — though your alloy hardness needs to match the velocity.
| Weight | Profile | Best Use |
|---|---|---|
| 125 grain | Semi-Jacketed, RNFP | .357 Magnum defense/hunting |
| 140 grain | Semi-Wadcutter | Versatile, good for both cartridges |
| 148 grain | Double-End Wadcutter | .38 Special target/bullseye |
| 158 grain | SWC, Round Nose, FP | Most popular all-around weight |
| 180 grain | Flat Point, Keith SWC | .357 Magnum hunting, heavy loads |
This is where .38/.357 casting gets interesting. The wide velocity range means alloy hardness is critical:
The 158 grain Keith SWC is considered by many to be the definitive cast bullet for .357 Magnum. Designed by Elmer Keith, it features a wide flat nose, a sharp shoulder, and a large grease groove. It's accurate, effective, and feeds reliably in most revolvers.
Cowboy action shooters are among the highest-volume cast bullet users. Matches require hundreds of rounds, and the sport's rules favor lead bullets. The .38 Special is the dominant cartridge in cowboy action due to mild recoil and low cost. Flat-nosed bullets are required by most match rules for safe target interaction. A cowboy action competitor shooting 200 rounds per match and attending weekly events needs 10,000+ bullets per year — making casting almost mandatory for serious competitors.
The M2R Automatic Casting Machine handles .38/.357 and dozens of other calibers. Perfect for cowboy action shooters, competitors, and small manufacturers.
View the M2R MachineYes — that's one of the great advantages of this pair. A 158 grain cast bullet sized to .358" works in both. Use lighter powder charges for .38 Special loads and heavier charges for .357 Magnum loads with the same bullet.
Most modern revolvers shoot best with .358" bullets. Older guns and some lever-action rifles may prefer .357". Slug your barrel to determine the groove diameter and size .001" over that.
Leading in .357 Magnum at full power loads almost always means the alloy is too soft or the bullet is undersized. Try a harder alloy (Lyman #2 or heat-treated wheel weights) and verify your sizing diameter. Proper lubrication with a hard lube is also essential at magnum velocities.