I am getting closer to reloading some Lee 457-340-F COWW cast bullets at 1400fps or less for use in a Henry lever gun. As with all things these days, availability of components is challenging (read that PIA).
The weapon is a Henry H010B, levergun 22", 1:20 twist.
For large primers I have: CCI #34, Winchester LR Magnum, and Winchester LP/M.
For powders more or less suitable for 45-70: IMR4227, Varget and Unique.
I am loading these with/for a friend who is currently shooting Precision One 45-70 Trapdoor 350gr ammo at 1350fps. He wants to stay mild. On the powder choices, IMR4227 seems to be intended for heavier boolits at higher velocities and I've read downloading IMR4227 is a big BoZo no-no. So that leaves me Varget and Unique. Since powders are so hard to come by these days I am reluctant to fill those huge cases with 46+gr of Varget when 12-14gr of Unique will give me 1100-1200fps. Still undecided but leaning towards Unique (cost is not the deciding factor, but rather availability and near term replenishment).
So now for primer options. I question the use of the harder cupped CCI #34 in the Henry, having no idea how strong the firing pin strike is. So now to choose between the Win LP/M or Magnum LR. Since we are going with relatively light bullets and low power loads I'm thinking the Win Large Pistol/Mag primers would do well with Unique's (few grains in a big case) and not enough pressure to worry about pierced primers or would I do better with the Magnum rifle primers?
Thoughts and recommendations for the components I HAVE on hand.