I'm going to start loading 270Win and I have many Lg Mag rifle primers that I use for the 300WM.In all the manuals I have the 300wm calls for a Lg rifle primer but I keep 1gr from max load to allow for pressure when using the mag primer.Do anyone use mag primers when loading 270Win?If so how far from max load do you stay? 1gr,2gr??If you are wondering I will be loading 130,150gr Bullets with H4831SC.Thanks
270 Win & Mag Primers
- Thread starter jwk
- Start date
When we loaded for my .270, the load I used (for a P/Hale) was 54 grs IMR 4350 pushing a 130 Sierra BT and a mag primer. I never saw any indication of high pressures - all I saw were subMOA groups - until another friend loaded the same thing for me, mistaking H4350 for the IMR 4350. That load knocked out primers, kicked like a mule and stuck cases in the chamber. Point being, there are arguments that a magnum primer can change pressure curves dangerously, but we've never seen that to be the case in any modern bolt rifle and conventional big game calibers.
