ArizonaShooting.ORG

Damn .. just finished loading up 50 rounds of .40 using some 180gr berry's bullets I had around.

I used Longshot powder and Min for Berry's is 6.3 and max is 7.5. I used 6.5 grains but being still a little wonky from being sick for a week I inadvertently used CCI 550's instead of the 500's. So .. Magnum primers

I am 99% sure they are still safe to use in my M&P and my Sig229 but before I take the final step and crimp them ... I thought I would check with some of the knowledgeable folk here.
Thanks in advance for any input
Alex

I have experimented with Mag primers and have seen little difference. That being said, in .40 using max bullet weight I would not do it with a max load. You seem well below max. I would touch one off and take a look at the brass. No pressure signs go ahead. You can also shoot a couple over a chrono if you know what the chrono is for the load with a regular primer.

The other option if you have access to a chrono is to load 10 identical rounds with a regular primer and shoot that over the chrono then test the mag primer load.

The most obvious is to pull them all.

Dan...

You're safe, but as remow said, shoot one and take a peek at the brass for pressure signs, then continue on.

thanks guys!!!!!!

No worries, I know many folks who load .40 for competition uses and use small rifle primers. They do this because they can just buy lots of SR primers and use them for .223 also. I have used SR primers for .40 before but since I also load for many other pistol rounds that use SP primers, I still buy and use them. As others have said, as long as you are not loading at the max level the slight increase you may get from the SPM primer will still be within acceptable limits.

Thank you Intel!

I have loaded magnum primers when I didn't have regular no problems for me

As long as they're not already at max you should be ok.
Like stated above. Shoot one and check just to be sure for any obvious signs of stretching, cratering, piercing, flat primers, smeared headstamp etc.