I would be interesting to see if just a primer change makes the difference Chap.

Maybe I should hold off modifying the breechplug until I do that. I was using the standard CCI 209s (not the magnums). I've been doing a little web browsing and apparently CCIs are on the low end of all the 209s with respect to flame temperature and gas volume. I did have a pretty good sabot fit and really leaned on the ram rod.