Primer experiment

[Alamstutz]

Primer experiment

Recently I had an opportunity to buy 1000 cci magnum small pistol primers. I had some concern about using them so I conducted an experiment. I loaded 20 identical .40 S&W cartridges and put CCI magnum primers in 10 and regular CCI small pistol primers in the other 10. I fired all 20 thru my chrono and the results were: the average of the ten cartridges with magnum primers was 859 ft per second. The average of the ten standard primers was 854 ft per second. I was surprised with these figures and my conclusion is that, in this application, there is virtually no difference in performance between CCI magnum small pistol primers and CCI standard small pistol primers.

I am wondering what any of you might make of this information.

[superdude]

What gunpowder? What bullet weight? What OAL?

I'm not surprised by the results, but it might depend on what gunpowder is used. Some gunpowders might respond differently than others.

[Hi-Power Jack]

I use them interchangeably.

They are probably (IMHO) the least important compenent in reloading -

necessary, of course, but changing powders or bullets or bullet weight/type

or powder charge is much more important.

Of course, if you're talking re: top of the line powder charges, it's possible

that primers could be of some concern - but, probably not too much. IMHO.

[Steve RA]

About the same result I had trying Tula LPPs in Federal LPP cases with 4.2 Clays and a 200gr LSWC against Federal small primer cases with same load and Tula KVB-223 SRPs. I only did 5 of each where you did ten and neither result would impress a statistician with the small base size. I'm pretty well convinced in my own mind that the differences are negligible.

[jstagn]

I used Winchester large pistol primers (for standard and magnum loads, according to the box) the Winchester ran about 30fps faster than federal, with 4.1 gr Clays (45acp). You could hear and feel the differences. Solution, use .1 less.

[Toolguy]

In my revolver loads, the difference averages about 15 FPS faster with Fed. sp Mag. than Fed. sp Regular. Most loadings have a greater FPS variation with all the same load so I use them interchangeably. These are for light and mid range target loads. I use Mag. Primers for Mag. loads.

[Dr Mitch]

I only use small rifle primers in my pistol loads, FWIW. The reason is so I only have to stock one type of primer.

Never saw a measurable difference on the chrono between SPP and SRP, but I also didn't expect too.

Edited July 26, 2014 by Dr Mitch

[Alamstutz]

What gunpowder? What bullet weight? What OAL?

I'm not surprised by the results, but it might depend on what gunpowder is used. Some gunpowders might respond differently than others.

Powder was PB 4.2 gr. 180 gr xtreme RNFP bullet. OAL 1.31. All the same for both batches of ten