mog75,
Trail Boss requires a lot of "bullet pull" to burn consistently, not just from a sturdy crimp but from the case itself. This is contrary to what a lot of people would guess.
Actually, that kinda sorta makes sense as even though the charges are light in weight, there's a lot of "stuff" to light. I've got 30 .45/70s loaded with 16 grains under a 350gr LC for my Ruger and I didn't crimp. If they don't shoot well, I'll bring the rest home and run them through my Lee FC die.
The .38s I shoot are crimped pretty hard, but the .243s with 100gr Sierra PHs weren't and shot pretty well.
