I recently picked up RIA 1911 in 10mm so I started casting and reloading 10mm. Now I reload other calibers and I use my FCD on all my pistol rounds. Never had any problems doing this and I never had FCD size down my projectiles. I started loading Lee 401-175-TC PCed sized to 401 with my new Lee 40 cal die set. I always seat and crimp as separate stages on my press. After I seat my .401 bullet and at this point neck tension alone is holding the projectile tight enough where I cant manually move it. I do end up with slight bulging where bullet was just seated, not uncommon when seating larger cast projectiles. Normally I run it through FCD to iron out the sides but i never had FCD size me projectiles but now it seems to be sizing them down to around .397 from .401.
Since I'm new to 10mm I thought maybe some brass was thicker but I tried both Armscor and Sig brass and they both did the same thing. I've see that with 300AAC but its mainly because i cut down 5.56 brass so some might be too thick.
Before I realized what was going on I loaded and shot about 30 test rounds (WSF-6gr, #9-12gr). Here is the kicker though. At .397 these rounds were fairly accurate from what I could see as i shot these unsupported and I had no leading anywhere. This surprised me very much. I was expecting to see leading somewhere in the barrel with an undersized projectile like that.
No I didnt slug my barrel. I tried it once or twice and i never got any consistent results so I load to max chamber/troat fit which usually gives me good results. If it doesnt I get that barrels throat reamed. Size up and try again.
I did run into few posts of people complaining that their carbide ring was too small and few even removed it. Dont think I'm there yet.
Anyone else with carbide ring in Lee FCD that was too small? Should I contact Amazon or Lee? Is it even an issue if my gun functions and shoots accurately? I dont want to spend a lot of time and money trying to fix whats not broken.