Substituting magnum primers?

[Lester Polfus]

So hypothetically speaking, if a guy were to have bought a shit ton of CCI Magnum Large Pistol Primers, instead of regular LPP's, would it be possible to still work up mid-range 10mm practice loads with them without incident?

Asking for a friend...

[txdpd]

Your friend shouldn't have any problems as long as he starts low and watches for pressure signs, and doesn't try to put large primers into a small primer case.

[nate89]

Seconded. I have a friend who has shot plenty (ie. over 10k) of 9mm with both small rifle and small pistol magnum primers. Like any other reloading, work up from below maximum and use common sense. I don't know about cup thickness between magnum and standard, but you would also want to verify reliability in igniting the primers, whatever you plan on using, especially if modifications to the mainspring or striker spring have been done for example.

[JFK]

Should not be an issue if you work up and use good method.

I don't have personal experience with this but there are plenty USPSA shooters that shoot 9mm Major and use magnum or rifle primers.

[Lester Polfus]

My friend is glad to hear that, although it might have been the tipping point to go out and buy that .44 Magnam I've, I mean, he has been thinking about getting.

Thanks.

[olstyn]

I've occasionally read of issues with magnum primers not sealing the back of the case as well as normal primers when used for non-magnum loads due to being harder and thus not expanding unless fired at higher (rifle/magnum) pressures. This is reputed to cause accelerated breach face wear via flame cutting. I've never personally had cause to buy magnum primers, so I can't speak to it from personal experience; I'm just passing on what I've read on other forums. Given that max pressure in 10mm isn't much different from 9mm or .40 S&W, I expect any issues that could be caused would be similar.

As far as 9 major shooters using magnum primers goes, that's a whole different ball game. 9mm at 170PF+ is significantly higher pressure than SAAMI max, and thus would be similar to shooting the magnum primers in a magnum load.

[busdriver]

I've read similar breach face erosion stories. My 9 major load is probably 45k ish psi, and I use rifle primers. No issues at that pressure.

[Hambo]

Here is what CCI says about magnum primers http://www.cci-ammunition.com/produc...ers.aspx?id=29

Mainly it's about ignition/powder selection.

[mtnbkr]

When I first started loading back in 1998, I bought mag primers and used them for 357mag AND 38special. No issues I could detect...

I have a bunch of SPM primers, but nothing that requires them, so when I run out of SP primers, I'll just use the SPM ones. That's years down the road though.

Chris

[Peally]

Just load em and shoot.