I have on order a new model CVA Accura MR-X .45 cal rifle. I also have ordered a LEE SC MOLD 450-294M IMPROVED MINIE 45 CAL mold. This boolit has a hollow base and I'm hoping will do well in the 1-22 twist Bergara bbl. I'm planning on using loose Triple Seven as a propellant. My question would be in casting these boolits, if I should go a bit harder than soft lead with the maybe faster spin and velocity soft enough for the skirt to flare to grab the rifling's. I do plan on shooting some saboted or skirted boolits but would like it if I could get away from the plastic. I've watched a bunch of video testing this gun and it has great accuracy with a variety of loads.