Change in load for CCI #34, milspec primers.

[GarandOwner]

I am thinking of getting some of CCI's #34 Milspec primers for use in my Garand. I have never loaded with Magnum primers before, anywhere I look it says not to use magnum primers unless the load calls for it. My question is how do you know what is a safe load to use magnum primers? Or is this just the reloading manuals way of covering its own butts by saying don't use magnum primers unless called for?

 

[Mark whiz]

The switch to a magnum primer is NOT as big of an issue as many make it out to be - UNLESS the load is already near maximum pressure already with a standard primer. Only the individual loader knows how close he is pushing things in the 1st place and needs to decide accordingly.

But just because one could use a magnum primer, that doesn't mean it would be of any advantage to help. A load that works well with standard primers may be over-driven and all over the place with magnums.

Specifically, for the #34s, it has been bounced around alot as to HOW "magnum" they really are. I've used them in ball powder loads in my M1A interchangeably with standard primers and even Win mag primers with no noticeable affect on accuracy or point of impact.

Generically speaking, mag primers are typically spec'd for ball type powders to insure good ignition. In addition, the #34s are supposed to be harder for use in mil-spec arms to prevent slam fires and since most mil-spec rounds use ball powders - it's a good marriage.

The absolute SAFEST way to go is to stay with the manuals recommendation - but a little info and common sense goes a long way too.

 

[FieroCDSP]

I did my work-ups with the 34's so I'm not sure how they react at max loads, but the loads I'm making for my SKS are at about mid-point between the start and max. I don't see any real indications of near-max pressures, and the accuracy seems to be good.

The big thing with the arsenal primers is preventing slam-fires, and this they do well. I haven't had a single light strike either, so that's good. As stated above, use them as a standard and approach max-loads with more than the usual caution.