We’ve all heard that one before, right? “There’s no point to the .357 Magnum in a snubnosed revolver, from a barrel that short you might as well carry a .38.” Well, thanks some some exhaustive testing by Chris Baker and the LuckyGunner Labs team, turns out that’s not really true.
As part of his ongoing clear gel testing of different small arms ammunition for the LuckyGunner ammunition store and its sister blog, Chris collected 38 different kinds of .38 Special and .357 Magnum ammunition, and shot them into denim-covered gel from two different length barrels: a 4.2″ Ruger GP-100, and a 2″ Kimber K6s snubbie. The results were pretty eye-opening: Out of the 18 .38 Special rounds tested, only 4 met FBI standards for penetration with expansion in 5 out of 5 bullets, and only 3 of those four gave the generally recommended 150% expanded diameter. The .357 Magnum was a different story altogether: 14 of the 20 loads met FBI standards with 5 out of 5 expansion, and 9 of those loads gave the recommended 150% expanded diameter.
This means that the .357 Magnum snubnose gives its owner 4-4.5 times the choice of suitable defensive ammunition that the .38 only revolver gives! That’s a pretty big difference!
Why did the .357 Magnum perform so much more consistently? Simply, it has more energy available to force the bullet to expand greatly while still penetrating to the minimum FBI diameter. I cover the mechanics behind this in two previous posts: Ballistics 201: Introducing a New Way of Thinking About Terminal Effectiveness – Force, Energy, and Work, and Ballistics 201: Introducing a New Way of Thinking About Terminal Effectiveness – The Energy Budget.