I would think truncated cone would feed better having smoother edges. That will be my next purchase after I'm through with these.
They may feed well, but I have been battling the same thing. I load all my 180gr TCFP FMJ or plated bullets to 1.130". I have 1000 Friendswood 180gr TCFP cast bullets on my bench as I type this. I have tried everything from 1.165" down to 1.100". I have settled on 1.105" which passes plunk test, mag test and cycle test. I dropped my start charge by 15% with W231 which worked well, but not what I was wanting. My next order will be SWC. My main reason for TCFP was for IDPA practice. I use Berry's RSFP for comp, but wanted to reduce cost of practice. My goal was to load using WST since I load WST for comp. Once I use up these I may just go back to plated.