Can small pistol magnum primers be substituted for small rifle primers?

[Bear324]

Or vice-versa?

The width is the same but the depth is .002 different.

Do they have the approx. same flash and igniting potential?

Thanks,

Bexar

[Rocky Raab]

It's one of those "kinda sorta" things.

The cups on magnum handgun primers are thicker to withstand the much higher pressures of some rounds (mainly the 357 Magnum's 35kpsi compared to the 38 Special's 13kpsi). But that doesn't get them into rifle pressures of as much as 60kpsi.

So there are more factors to consider than flash and ignition ability - and physical size.

If you had nothing else and still had to load rifle rounds, you could use SP magnums if you stayed towards the middle of the load chart, or even at Start loads. But going the other way and using SR primers in handgun rounds will leave you with high primers, which are never good and can cause either slamfires in a semi-auto or cylinder lockups in a revolver.

[Firebird]

Actually, small rifle and small pistol primers should be the exact same size, any differences you are measuring is due to manufacturing tolerances. There are several problems with substituting between rifle and pistol primers. The first is that the strength of the primer cup varies, rifle primers being spec'ed for higher pressures than pistol primers. So using pistol primers in a rifle cartridge can lead to pierced primers due to the higher pressures. On some rifle cartridges this isn't a problem - 22 Hornet loads are often spec'ed as using pistol primers; black powder duplication loads for cartridges like a 45-70 or 32-40 could also easily use pistol primers as the pressures just aren't very high. The second problem that can rear it's head is that pistol primers don't always have the "fire" (technical term is brisiance?) of rifle primers, potentially leading to squibs and mis-fires when trying to use a pistol primer and a hard to ignite rifle powder.
Going the other way can also lead to problems, not all pistols have enough energy in the hammer/striker impact to properly ignite a rifle primer - the primer cup is stronger to hold more pressure so it's harder to crush the primer pellet inside it; again this can lead to squibs and mis-fires. The stronger "fire" of rifle primers may also raise the loads' pressure, so you have to re-develop the load from the starting powder level again.

[kodiak1]

Bear as stated it pretty much depends what you are loading and what kind of efficency are you looking at getting out of your load.
If you are loading pistol Cals and shooting them in rifles go for it.
Black powder lots of time getts better ignition from pistol primers as opposed to magnum rifle primers.

Ken.

[beanflip]

NOTE:---Test sample of 10 cases of each size of primer of different makers

Large rifle mag ---- thickness .013 to .014

Large rifle----- thickness .013 to .014

Large pistol mag----- thickness .013 to .014

large pistol ---- thickness .013 to .014

small pistol ---- thickness .013 to .014

Small rifle mag ---- thickness .013 to .014

Small rifle ---- thickness .013 to .014

The height measurement sample size of 10 each of the following primers:

Note: New unfired primers of different makers

Large rifle mag ---- height of .114

Large rifle----- height of .114

Large pistol mag----- height of .112

large pistol ---- height of .112

small pistol ---- height of .110

Small rifle mag ---- height of .110

Small rifle ---- height of .110



This is only a sample of measureing and comparing of primers and is not saying that it is ok to swap them in anyway shape or form.

[azrednek]

Rather than risk any problems, see if you might be able to find a one for one trade for rifle primers in the swapping and selling section.