9mm and magnum primers

[doug strong]

I just finished loading 500 rounds of 9mm with cast boolits. As I put things away I found I that I had used magnum primers. What would the effect be? am I screwed?

[zxcvbob]

In general, the pressure will be higher (maybe quite a bit higher), and the velocity will be slightly higher. If you were not loading too close to a max load to start with, you're probably OK. When I first started reloading 9mm, I only used Federal small rifle primers -- but I developed the loads that way and worked up from minimums.

[doug strong]

Can anyone tell me the rough idea about each primer's characteristics? I know that small is small and large is large but what is the difference between rifle vs pistol and regular vs magnum.

[SciFiJim]

Small rifle and small pistol are the same size. Small rifle have a thicker cup to withstand higher pressure.
Large rifle are slightly taller than large pistol. The rifle primers also have a thicker cup to withstand higher pressure.

The rifle primers have more power than pistol primers.

That's the quick and dirty on primers. You could writer doctoral dissertations on why there is not a one size fits all primer.

A good comparison of brisance (power) is here.
http://www.castingstuff.com/primer_testing_reference.htm

[Shiloh]

In general, the pressure will be higher (maybe quite a bit higher), and the velocity will be slightly higher. If you were not loading too close to a max load to start with, you're probably OK. When I first started reloading 9mm, I only used Federal small rifle primers -- but I developed the loads that way and worked up from minimums.

I have some small pistol magnum primers, so I tried them in .38 Special.
I didn't have the chronograph, so I have no figures of comparison. No felt difference between the two. Everything else was the same.

As stated this is .38 Special, NOT 9mm. 9's and .40's are high pressure rounds.
.38 Special isn't near as high.

SHiloh

[JScott]

I accidentally bought some Remington 5.5's (magnum) instead of 1.5's for use in a 9mm. I didn't chronograph them so can't tell for sure but didn't notice a dramatic difference in performance. I was not shooting top end loads. I did notice that the cups were seemed harder as the firing pin strikes were significantly lighter. They all went off though. Like any component change, reduce your charge and work up if you use them.