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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