Any difference in LR Mag primers from CCI, WW ,or Federal? Which primer would you use in a Weatherby 340 mag?

I've found Fed. to be a little softer & WW a bit harder (softer primers flow/flatten a bit more). I've used them all & it really comes down to which works best in your load. I would try a box of each, load your favorite load & sub the primers. The accurate one wins!

I think the Federal mag primer was developed extra hot with the Weatherby magnum in mind when this was released. It was a hotte primer at the time. Use what ever brand you like and work the loads from there. Remember if you change primer it will change pressure, so you will have to back off on the charge and work your way back up.

Hcliff

I have several of the Weatherby's including 300, 30-378, 338-378 which I reload. As mentioned, the Federal 215 primers were developed with the larger Weatherby cases in mind. I think Norma (loads Whtby factory ammo) uses those primer.

I use 215's exclusively for all my Weatherby's, however, I prefer the Federal 215 Match Grade Primer, they may be a little more consistent than standard 215's. Most reloading information I see uses the Fed. 215's, however, some sources (reloading manuals) use other primers for the Weatherby's.