The guy at CZ said he's seen this before on older 75b's. Mine is dated '96, though for its age it doesn't have a high round count (1,200 rds., I'm the original owner). During recoil, that part of the barrel is hitting the inside of the slide just in front of where the rails end. I can't see any wear on the slide though, it looks slightly polished perhaps. I guess the barrel is softer steel. I've replaced my springs once and am currently running a 15lb. Wolff recoil and 17lb. hammer spring.
I'm sure I could chamfer it myself, but they offered, so should I ever pass it on or sell it I think it's better to show the work was done by CZ and not on my tabletop. Function has not been affected. It cycles properly and groups very well. I was relieved that they didn't think it was a big deal.
I don't shoot it that often 'cause my CCW's usually get all the range time, but it was my first handgun so I guess I have a little bit of a sentimental attachment.
