The next step is not deforming or shaving them during seating or crimping. They wont tolerate as much battering as harder slugs, but the alloy should bump up under pressure.
Dont give up on the TiteGroup. Try it with the softer slugs. I'll bet it works fine...Should you get a hint of leading, shake them in a bag of liquid Alox. Its cheap.
What dies are you using?
Most guns in 45 Colt I shoot these days have 454-455 throats and Ive had good luck with RCBS Cowboy dies with expanders made for cast bullets. I dont know what diameter it is, it just works well. The seaters also come with both FN and RN stems.
A good bell on the case mouth helps. The same goes for coated bullets and shaving off the plating.
Good luck to you.
