Curious visit to Cabelas today

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Ron IL

Dec 29, 2016
Southern Illinois
I have read a lot of threads about using small rifle primers in place of small pistol primers. I found a box with 42 small rifle primers in it and loaded them up in a 38 case for my GP100. I loaded them with the same bullets and cases as some I had loaded. I used Bullseye powder. I took my chrono and shot the 42 and 42 of my regular loads with small pistol primers. The rifle primers averaged about 12 fps more than the pistol primer loads. I think the difference would be different using other powders. I think some powders respond more or less to the primer change depending on burn rate. So when primers start showing up I will buy either one I can get. I think when primers show up I will retest this and will test it with Unique too. I use it a lot.
Nov 5, 2007
Dallas, TX
Ron IL:
Thanks for that. I too have used small rifle primers, but in 357, not 38. I'll have to try them in 38's.

I did make it to the range today. The large pistol magnum primers worked quite well in the 45 Colt. No signs of over pressure, such as a flattened primer either. I loaded them with Unique and went about 5% below my standard load, which is on the light side of what's in the printed manuals. I shot two different loads, side by side. Both Unique, both 250 grain poly coated bullets. I don't have a chronograph, however, the felt recoil was very similar. As far as accuracy, the magnum primers actually grouped better.

It was an interesting experiment. While I will use standard large pistol primers in the future, I'm glad to know I can use the magnum primers in a pinch.


Nov 2, 2014
Yrisarri, NM- high in the Manzanos
Kevin said:
No signs of over pressure, such as a flattened primer either.

To my knowledge, primer flattening is not a reliable pressure sign in handguns. I don't doubt that your loads are safe, but evaluating their safety based on primer flattening could easily result in loads that are unsafe in some guns (particularly the case with the .45 LC cartridge).


Aug 22, 2007
Lewiston, MI USA
I think all reloading manuals now probably show lower power loads for most every load compared to 20 or more yrs ago.

I have a couple older Sierra/Hodgdon manuals and it is interesting to compare--their apples to apples.
Use Sierra 800 BULLETSMITHS(800-2238799) for any questions about any loads-Sierra or not. I bet they have every loading reference available, current model.

They will often say "wait let me check here"