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Good video showing some real numbers using small pistol, magnum small pistol, and small rifle primers in a pistol.

Thanks for posting. Interesting. How about using small pistol primers for small rifle? Would think it should work.

Bearcatrp wrote:Thanks for posting. Interesting. How about using small pistol primers for small rifle? Would think it should work.

Given that rifles run at higher chamber pressures than pistols, I'm guessing that would be a bad idea.
Couple the increased pressures with thinner/softer primer cups on SPPs, and you run a risk of piercing primers, if not completely blowing them out.

That said, I'm sure there are numerous people on this board who are more knowledgeable than me on this issue.

ex-LT wrote:Given that rifles run at higher chamber pressures than pistols, I'm guessing that would be a bad idea.
Couple the increased pressures with thinner/softer primer cups on SPPs, and you run a risk of piercing primers, if not completely blowing them out.

Pistol primers in a rifle cartridge is a recipe for disaster.

Only use pistol primers in pistol pressure loads. Some pistol rounds that are higher pressure do require a SR primer (like the .454 Casull or the 9x23 Win.

If you were making gallery type loads, ie, very low velocity, low pressure loads, it might work OK in a small primer case.

Look at some .17 HMR cases after firing. I’ve seen some cracked rims there with powder gas leakage, and that’s a low pressure rimfire case. Overall, it’s not a good idea.

Scratch wrote:Good video showing some real numbers using small pistol, magnum small pistol, and small rifle primers in a pistol.

Good video. Thank you for posting.

Thanks for posting, good to know. I was reading on another forum where a person was warning not to interchange magnum or rifle primers for pistol loads in the upper range.

That video just showed not much difference in pressure. So why not small pistol primers replacing small rifle primers? I wouldn't do it unless I have no other option though.

A small pistol primer is made to handle relatively low pressures- under 33,000 PSI.

The primer cup is not as thick. This is also due to pistol mainsprings not being nearly as heavy as rifle ones.

So, while the priming compound might be similarly brissant and not change the pressure of the load, the ability of the primer cup to hold that pressure is much less. (I would not trust that video's information... IF I was going to substitute primers, I'd be starting really low and pressure testing them with my old Ohler PBL- but I'm not sure where all the parts are...)

From personal experience with the 9x23, using pistol primers resulted in flame cutting of the breech face and occasional pierced primers as well as blowing them out of the case. The operating pressure for 9x23 major loads is about the same as a .223. (its predecessor, the "super Cooper" was a .223/5.56 case cut back to 23.5mm and fired in .38 Super chambers- it was an attempt to develop a 9 mm "major" round for IPSC competition back at the start of the "arms race" in IPSC.)

I asked CCI if their small pistol magnum primers were really just their regular small rifle primers, something that I had heard...they responded no they are not, and they said not to use SPM as SR primers.

How about for subsonic only loads for 300 blackout? Pressure should be about the same as a pistol.

Pressure may or may not be pistol level. A heavy bullet going around magnum revolver velocity with a much longer, heavier bullet, and a smaller case capacity...

I would not do it personally.

Bearcatrp wrote:How about for subsonic only loads for 300 blackout? Pressure should be about the same as a pistol.

I load both 300BO and 30 carbine. I don't really see why I couldn't use SPM primers in those cartridges. For true rifle rounds sure I get it. But these rounds both use magnum pistol powder and in my case I am loading supersonic rounds with similar weight bullets to handgun.

Google tells me 30 Carbine pressure limit is 38,500 psi (44 magnum is 36,000) - 300 Blackout is at 55,000 psi.
That's a lot of psi bearing down on a small pistol primer.

Loading down from maximum in maybe a bolt action platform is a different ballgame altogether than someone perhaps running at the upper limit in a semi-auto.
In the case of the Blackout the potential for slam fires has to be considered too.

All loaders "pays their money and takes their chance", it's up to the person pulling the handle.
Do what you want, manufacturers make both small pistol and small rifle primers for a reason.