Lee Loader

I understand that the dimensions of SR and SP are the same but SR has a thicker cup than SP primers. So if SR is subbed for SP, there may be ignition issues - but maybe not depending on your handgun.

I have subbed REM 6 1/2 SR for SP mag primers. The Rem 6 1/2 SR primers have thinner cups than Rem 7 1/2 SR primers and on the box it says that Rem 6 1/2 SR primers are not indicated for 223 and other higher pressure small rifles.

Bayou

I need to do some caliper measuring. To my eye they look pretty close. But I have not done any really close exam. Right now I don't think you can get any small rifle primers, so the point is probably moot anyway. There do seem to be large rifle primers at least on some sites.

killian6pk wrote:I need to do some caliper measuring. To my eye they look pretty close. But I have not done any really close exam. Right now I don't think you can get any small rifle primers, so the point is probably moot anyway. There do seem to be large rifle primers at least on some sites.

SAAMI says they are the same in the small size, different in the large. Rifle have a harder cup to deal with rifle pressures and if your pistol strikes light you could have problems. There are other potential reasons for misfires when using SR primers in pistol cases but they all can be summed up under light strikes. When you move to the large primers there is a difference in the pocket depth. If you uniform your primer pockets you need a separate reamer for the pistol cases. There are pro and con arguments to uniforming primer pockets, but I come down on the side of uniform.

Stay well, be safe, make smoke

Mag primers were all I used to use. I do have to say, all loads were
worked up & fired over a chronograph, with all other signs of bad
pressure carefully observed. (Yup, just like any other load)
I'm my mind, just some extra ignition insurance, never had a problem.
Winchester WLP for standard or mag loads, I've used thousands of them
In 45auto & they remain my favorite.
Nowdays, I'll take whatever I can get.