So im hoping to put together some powder coated subsonic 300 blackout cast boolit loads for an AR, and am interested in something like the NOE 247gr hollowpoint mold. Im fairly new to casting so im still learning, but I do know that subsonic bullets tend to have a hard time expanding unless specially designed to do so. I was wondering a few things:
a) what lead hardness will allow a 30 cal 247gr hollowpoint to expand properly in a person or animal, assuming that its even possible? (these are hunting and defense rounds)
b) Will said hardness cause the boolit to get chewed to hell in an AR action?
c) Is hollowpoint the best bet for this task? worried that round/spitzer bullet will pass right through (TwangNBang did a video shooting ballistics gel with the spitzer tip NOE 247gr, and it went clean through 2 gel blocks without the slightest hint of tumble or expansion), and worried that any flat nose wont cycle reliably on the feed lips.
d) am i expecting too much out of these cast boolits and resort to machined expansion rounds like the Lehighs or Maker REX's?
Thanks for the tips!