Just a few suggestions that may help...
First, it sounds like you need to tighten up that crimp a bit. I've loaded tens of thousands of .45's with both jacketed and lead bullets and always used a firm taper crimp. Feeding reliability was always high on my priority list, but accuracy was never diminished.
Second, you could remove a few thousands from your expander plug to slightly reduce the inside case diameter, resulting in a tighter friction fit between case and bullet. Along with the proper crimp, it can make a enough difference to be worthwhile.
Third, check the feed ramp on the Citadel. It's not uncommon for those less expensive 1911's to need a little polishing in that area. A rough feed ramp can and will affect feeding, and may contribute to bullet setback.