Needing to put some "after break-in" rounds thru my new 9x19 AR pistol I figured it a good opportunity to run this test & put a fine point on it, at least from a velocity standpoint. Pressure is another thing.

The primers: CCI-500 & CCI-400, SPP & SRP respectively.

The AR pistol: Freedom Ordnance FX9-P8 with an 8" barrels.

All of my pistols are hammer fired, I don't have any striker fired. That area I can't speak to other than they are generally considered to have a lighter strike & would need a closer look before using with SRPs.

The handloads were assembled with F-C/Federal 9x19 brass (used) & Zero 125gr JHPs.

The powders: Power Pistol, LongShot, & AA#7, each charge dispensed from a RCBS Charge Master 1500 & double checked on a Lyman Ohaus M5 beam scale to (+/-) 0.05grs.

Power Pistol & LongShot charge weights were: 6.4, 6.7 & 7.0grs. & AA#7 was 8.4, 8.7 & 9.0grs.

COAL: 1.125"

These loads are full/heavy loads that I've used in many of my 3rd Gens without any issues but that guarantee's nothing for you in yours.

WARNING: some of these loads are non-standard charge weights & are (+P) or above. Use at your our risk!

The "fps" readings in the chart's graph below are the average of the (3) different incremental charge weights, for each powder, (10) rounds each, for a total of (30) rounds per graph bar.

Total tested: (180) rounds chronographed with my LabRadar at an indoor range.

As commonly stated, there's little difference in velocity between the two primers in the 9x19. Other cartridges/loads may show different results.

I did a similar, but smaller, test using my 5" 9x19 Dan Wesson 1911 PM-9 with a couple of these powders/loads with the same small difference in velocity.

Also, the SRPs ignited consistently & without issues in this 1911 which has a standard power hammer/main spring.

With this done I plan on using SRPs in all of my AR pistol loads & save my SPPs for my other pistol loads.

One note, I'm perplexed why AA#7 "under-performed" in this particular test as in the past it's done much better than P-P in my 5" 1911.

And L-S which usually chrono's a little slower than P-P, using the same loads, seemed to like the 8" bbl. & out-performed the other two. WTH?

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Waiting for the break of day

I have found the same results as you have. Even with the striker fired pistols. However, if you try them with an unlimited pistol/revolver you may get some light indent misfires as a result of the lighter springs. Not enough energy to ignite them it what I found.

Excellent report and format. By chance have you tried these loads in something like a Ruger PCC?

Regards, Rick Gibbs

While it appears that there are no significant differences in average MVs as a result of SRP vs. SPP, you might consider performing a statistical T-test on your data to quantitatively confirm that. Pretty simple to perform that test, easily handled by Microsoft Excel. See T.TEST function

Quite a few years ago, I did a fairly rigorous test to determine if there were statistically significant differences in average MV due to SRP vs. SPP using different loads in .38 Special. There weren’t any at the 0.05 level. Very crudely, that means that you can have about 95% confidence that there is no difference in average MV due to the type of primer used. It is actually much more complicated than that, but there no point in clouding the issue any further as even professional statisticians do not agree on an exact meaning of a significant confidence level. There have even been Supreme Court decisions on that topic.