Sound like shoulder set-back.
Re-set your dies.
Let the expander ball do all of the case mouth expanding, don't bell.
Don't use any crimp, none, zero. (This is where I think the shoulder set-back.)
Crimp only if you are having a problem with too little neck tension. I would prefer to polish the expander ball (makes it a little smaller and smoother) over crimping, but that's just me.
A gauge would be nice, I guess. I don't have one and most likely never will. My 'gauge' is the chamber of what I'm feeding.
Small base sizing dies.... Got a set some place in the stack of stuff I don't use. SAAMI spec sizing dies, the standard ones, seem to have been working just fine for me for the last 40 odd years. Oh yea, I did use those SB dies when I built a target bolt action in true .223 chambering, but the regular base sized brass worked just as well. Maybe your chamber is ultra tight and you need them.
Your charge is not in question (at this time), you are not getting a good chambering.