Rifle casting and reloading is a whole different ball game than pistol calibers. The alloys are different and usually you need to use a gas check. I cast and reload for 223/556 (LMT-AR), 308 (30/30 and 30-06) and I have a .270 mold waiting to be tried out. Take a look at the cast boolits website
) as they have great info for first time rifle casters and .223 casting/reloading. Good luck.
best wishes- oldandslow