Primers and large Charges

[c east]

Shooting 109 grs of 870 in a Lapua mag.....I'm useing CCI BR Primers...Do I need to go with MAG primers?
Thanks

[BountyHunter]

Find out what your gun says! Look at the ES, is it under 10-14. If not, try some 215s or other mag primers and see what the results are.

Every gun is a beast unto its own and you will not know until you try.

BH

[Darryl Cassel]

Ceast

With the ball powder yes, I would go with the Federal 215 primer especially since your over 100 grs of powder.

Some people feel you don't need a mag primer till you get to 100 grs of powder or above.
I use a mag primer from 75grs and above in some rifles.


DC
Later
DC

[ricciardelli]

I would say the Federal 215 primer would be what you should use...

[Mark_in_utah]

This topic is of interest to me, because I'm working up some loads in my .338 RUM, and the velocity I'd expect just isn't there with WC872. I've put 103 grains of WC872 behind a 225 grain Hornady bullet, lit it off with a CCI 250 primer and I only get 2651 fps! This is in a Remington 26" factory barrel with a vais brake. The 103 grains is getting close to a compressed load. I have to shake it down pretty good to get it to the bottom of the neck.

Using 95 grains of WC852(s) with the same setup I get 3165 fps. No pressure signs with either load. What gives? Any ideas?

Mark in Utah

[Mysticplayer]

You are just running a powder with a pressure/burn rate more suitable to your rifle. Ths 872 was simply too slow for your bullet weight and bore length. If you were to switch to 300grMK, you would find the 872 to be a better powder.

That is why we test loads. You never what will be the magic combo. Going to do the same with my Mystic. Been using H4831SC which should be a great powder. However, vel and accuracy are not what it should be. Going to try H4350 to see if I can improve the performance.

Jerry