Sunday, June 09, 2024

Meplat Comparison and Terminal Ballistics

Assuming proper shot placement, the terminal effectiveness of non-expanding bullets on game or in defensive applications is determined by (a) penetration and (b) the bullet's meplat, or nose. The best effect on living things is obtained by a wide, flat surface. This causes the maximum amount of damage and also allows the bullet to penetrate in a straight line rather than tumbling or glancing off bone. Here are a few bullets suitable for loading in .38 Special or .357 Magnum:

Left to right:

  • Lyman 358429 SWC from Matt's Bullets. From his alloy it weighs in at 178 grains, is lubed with Carnauba Red, and is sized to .359". This is the bullet designed by Elmer Keith for use in his hot .38 Special loads that lead to the development of the .38/44 and the .357 Magnum.
  • Lee TL358-158, nominally 158 grains and .358", cast by me from 16:1 lead:tin alloy. It's tumble lubed with Lee Liquid Alox. I load these unsized, then run the rounds through a Lee Carbide Factory Crimp Die, so even if they are a bit large, the outside of the case is swaged down to SAAMI spec.
  • Speer 158 grain swaged SWC. Lube is some dry lube.
  • Lyman 35891 148 grain wadcutter from Matt's Bullets. It's also sized to .359" and lubed with Carnauba Red.
Of the SWCs, the Lyman and Lee have wider meplats with sharp edges, while the Speer's meplat is both smaller and the edges are more rounded. The wadcutter has a short button nose but it's the full diameter shoulder that does the cutting.

On top of a suitable powder charge any of these bullets will offer plenty of penetration. However, the Speer would be my last choice for shooting anything larger than a groundhog due to the nose shape. I'd expect any of the others to perform well on game, with the edge in long range accuracy going to the Keith bullet.

C.E. "Ed" Harris has written about the use of "full charge wadcutters," for hunting and defense, although he favors a 146 grain double end wadcutter cast from a Saeco #348 mold on top of 3.5 grains of Bullseye, giving 850 - 870 FPS from a 4" .38 Special revolver.

He's also written about the penetration of the Keith bullet fired from a S&W .38/44 Heavy Duty during a test at the FBI's range at Quantico, in which it penetrated through two calibrated ordinance gelatin and then bounced off a thick plywood backer board. It was something like 30"+ of penetration. (This was in a forum post but I don't recall where.)

If used for defense against people, hollow points are probably a better choice at least from a 4" or longer barrel. Both the Lyman 358429 and Speer swaged bullet are available in such versions. The FBI Load, AKA .38 Special +P 158 grain lead SWC hollow point has been proven in defensive shootings for decades.

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