Hi: I've got a CZ550 American in 7x57mm Mauser that seems to have an affinity for 162 grain bullets (would like to try the 154 Hornady SST one of these days) and H414. It also seems to like W760 powder. I heard somewhere that with W760 one needs to use mag primers. Since H414 is very close to W760, should mag primers be used with this powder as well? Or, is what I heard just full of bull-hockey? Thanks ... Tom Purdom

I've never used mag primers with either of these powders, and I use them both in a lot of different calibers. The only reason I can think of to use the mag primers would be for extremely cold hunting conditions. I tried some experiments with Re-19 using std and mag primers. Velocity jumped up a little, so did pressure signs, but on the range at -10 degrees, they did give more consistent velocities. - Dan

Tom, I have had better success with CCI 250 and Remington 9 1/2M with H414 powder in most cartridges I load for with that powder. Both accuracy wise and consistency shot to shot. Most of my shooting as well as hunting takes place in weather under 50 degrees F., and most whitetail hunts occur in 30 degree or lower temps. Your results may vary as you live in a warmer climate. I have noticed "ball type" powders hit the pressure spike with as little as .2 of a grain increase, while extruded single base powders seem to be more forgiving when increasing charge weight.

I also use CCI 250's in 30-30 Win in my single shot NEF's with Barnes X bullets and W748 powder.

I keep many primers of different types and when developing loads use them all as POI will change as will accuracy with different primers in standard and magnum.

For the most part I always come back to CCI 250's. That might change when the bricks I have with the same lot# are used up.

CCI-250's are an excellent primer for H-414. I haven't loaded that powder in my 7x57, but I use the combo in .270, and 30-06.