Originally Posted by clhman
I recently obtained a custom JP Enterprises AR-15. It has a 24" 1-8 twist. I am working up a load that my buddy uses in his JP. It is a 50gr Nosler BT loaded with 26gr of Win 748. I live in Alaska and will always be in shooting in weather under 50 degrees. My question is should I use CCI 400s or 450s? I have heard mixed reviews. Some people say use standards in bolt guns and magnums in ARs. Any thoughts would be greatly appreciated.
I really think it makes little difference in such a small case, even with 748, I have no problems with using standard primers in my 222. I did test to see if there was any difference. It worked out to be 20fps on average faster with the magnum primers. Velocity was consistent with either, so ignition is not a problem, and I regularly shoot in similar temps to you during the winter months.