Mine are at 1.195 right to the top of the crimp grove. Not using a 1911 though.
Are you having problems with seating the round with the barrel out using it like a gauge? If not is the action not closing all the way when you release the slide?
I would try a couple of things, with the dummy round. Pull the barrel and seat the round at 1.2 all the way in....see where it is hanging up. I don't know the if there is a term for this or not but barely size like 1/2 the way of a case...bell it completely put a pinbuster in and seat, put in barrel and seat all the way...pull round and measure...just make sure there are no marks on the front of the bullet that could indicate it got stuck and partially pulled out of the case when you were extracting, which would mess up your measurement. You might make a dummy to 1.15 and see if it will chamber. Don't know if I would go this short or not with this heavy bullet, but it is a 1911. Also, have you been successful with any other lead rnfp bullets regardless of weight in this 1911?
I'm baffled if the LFC didn't help in the troubleshooting, usually they will iron things out.
Good luck, I really like this bullet for pins.