Magnum or standard primers?

[gorillamotors]

Do you reload 6ARC with standard or magnum primers?

[Old Bob]

I've been using CCI 450's (Magnum) & CCI No.41's (Military) for AR reloads. For bolt gun reloads I've been using CCI 400 (Standard) & Federal GM205M's. I have some Federal AR Match primers but haven't tried them yet.

Most AR shooters use magnum primers 'cause the cups are made of harder material. It's to prevent the odd chance of a slam fire...

[kevad68]

For my bolt gun I started off using CCI400's and Federal GM205M's as well, but just moved to CCI450's to try to get into higher velocity ranges. Haven't really had enough time to test out the data out yet, so jury's still out for me whether it's worth it or not.

[StoneHendge]

For my bolt gun I started off using CCI400's and Federal GM205M's as well, but just moved to CCI450's to try to get into higher velocity ranges. Haven't really had enough time to test out the data out yet, so jury's still out for me whether it's worth it or not.

Magnum primers can sometimes ignite powder too fast resulting in a quicker pressure peak and subsequently less velocity. That was certainly my experience shooting several thousand rounds in converted 7.62x39 brass with large primers.

[IALoder]

After testing my LVR/105gr loads with CCI 450's, 400's, and Fed 205's, I'll be staying with standard primers for the loads. Same avg velocity, but lower es/SD's with the 205's and 400's. Accuracy difference was negligible.

[kevad68]

This is good stuff to know, saves my 450's for my BR loads!

[Bill]

Rem 7.5 all day everyday, yet to have 1 not go off, rifle shoots 0.26 moa