Quick Primer question

[dickn52]

Using an SMK 69gn for a .223 reload. 25.1 gn Varget. I have one box of 100 mag primers CCI 450's. I usually use the CCI 400 standard primers. What precautions should I use if I go with the Magnum primer? Do I back off the powder load? Suggestions requested.

 

[ARIZONA_F_CLASS]

Always back the powder off when trying any new combination, or bad things can happen!!!!!!

 

[bloc]

According to LoadData, you're ~ 1 gr beneath max with that bullet. I'd drop 1 grain further, load 3 rounds, and see what happens (you could probably tell after the first round).

I once did an experiment with my .270 Win. Chronoed velocities of identical bullets and powder charges and brass, but in half my loads I used mag primers, in the other half standard. I saw no difference in velocity. I saw no physical evidence of high pressure in one over the other (difference in primers, sticky bolt opening, extractor marks, etc.) either.

Your milage might differ.

DISCLAIMER: I kept all loads under max by 1 grain. But that's what I do, irrespective of propellant, bullet, brass or primer.

 

[dickn52]

Thanks everyone. Great advice as usual.