Smith & Wesson Forum - View Single Post - Standard vs. Magnum Small Pistol Primers: My Experience

Landric · 05-17-2009, 05:25 AM

A little while back I picked up some Winchester Small Pistol Magnum primers since I couldn't locate and standards. I loaded up some test rounds, half with standard primers and half with magnums, same powder charges, same brass, same bullets. I didn't have any overpressure signs with any of them. Here were my results (I have purposely left out powder charge weights):

.32 S&W Long, 100 grain RNFP, Trail Boss:

Ave Std. Primer: 570fps, Std. Deviation 18.08
Ave Mag Primer: 553fps, Std. Deviation 8.13

.32 H&R Magnum, 100 grain RNFP, AA#5:

Ave Std. Primer: 749fps, Std. Deviation 32.98
Ave Mag Primer: 798fps, Std. Deviation 12.11

.38 Special, 158 grain RNL, HS-6:

Ave Std. Primer: 884fps, Std. Deviation 30.27
Ave Mag Primer: 890fps, Std. Deviation 20.86

9x19mm, 130 grain FMJ, HS-6:

Ave Std. Primer: 990fps, Std. Deviation 20.79
Ave Mag Primer: 1043fps, Std. Deviation 19.70

9x19mm, 125 grain RNL, HS-6:

Ave Std. Primer: 1116fps, Std. Deviation 17.54
Ave Mag Primer: 1122fps, Std, Deviation 13.20

The only two loads that the magnum primers made any significant difference in where the 100 grain H&R Magnum and the 130 grain FMJ 9x19mm. The magnum primers seemed to be more consistent overall, though it generally didn't represent a huge change. I tested the magnums with my standard loads and the conclusion I came to is that it is safe to use magnums in place of standards in the loads I generally use. I'd test other cartridges and charge weights before using magnums in those loadings.

I'm happy with the results and I plan to use my magnum primers for the cartridges above.