Tatume, PM received - thanks for the info.

Now I'm confused - Tatume's info and 450 Ackley's last response indicate that my AR2205 loads (AR2205 is a little bit slower than 2400) were ballpark and should have at least gone bang every time, albeit running a bit on the "rich" side with soot and grease. So I don't need magnum primers or fillers but do I need to crimp the projectile in place? I haven't been doing this.

I've used cast in 308 and 375H&H and have never crimped those (and without issues).

(I re-read my original post last night and discovered an error "...I use this powder for cat bullets in my 375H&H." I meant "cast" but I guess "cat" is probably okay too.)