I am new to the reloading game, I reloaded my first 10 rounds, 1-5 winchester brass, 41gr. H4895 under 165sst's, primers are No.9 1/2M. Those were the only primers bass pro had. My question is, is 41gr. of H4895 to much for the magnum primer. 41gr. is the min. on my Hodgdon print out for the 165sst.

thanx, 6-10 Hornady Match brass (same componets
as use in winchester).

I haven't looked at the books, but I would say no. The rule of thumb is to reduce by one grain if going from a standard primer to a magnum. If you are at the bottom of the load chart for that particular powder, I don't see how there is any way on this earth you are going to be over max pressure for the .308.

And by the way, welcome to AR. A lot of good information here, and a lot of good folks wanting to help. I sincerly hope you enjoy your time.

j-b,

Welcome!

Magnum primers have a hotter, longer & more intense flash to ignite larger volumes of powder. They'll work fine in a load that has been developed around their use.

My Rule-of-Thumb is that as I approach >60 grs. of powder in standard cases or in Magnum cartidges (that almost always use more than 60 grs. of powder) then I use a Magnum primer.

On the other hand; in .222 & .223 Remingtons I use CCI450M's for all my loads as I develop them; similar to what you have just done, so they're now the Default Point and there will normally not be any issues.

However; when changing components; bullets, powder, case & primers in already established loads, I'd suggest backing off @ 5% (providing there is a reasonable 5% to back away from); after all you do not want to get too little powder in a load either.

Have fun with your new 308 Win. ammo.

Thanx for the info, I'm 10 reloads in, and I think this will be just as much fun as putting them down range. Seems to be a good community here at AR. Thanx again.

Powders, barrels, and brass vary so much that you never know what you are going to get as far as pressure goes. You will have to shoot them and see. I have found that the differences in standard vs mag primers may or may no tbe significant unless you are trying to ignite large doses of slow powders.