Cz jumpy barrel
 

My cz 527 in 7.62x39 has a loose spot in the barrel when i push a patch through it does a slight jump of about an inch just in front of the chamber. Looking down the barrel it looks fine i cant see any bulge. I noticed the rear sight boss was at his exact location. Its a part of the barrel that is not machined down as small as whats on either side of it. I have a winchester alaskan that has this same type of integral sight boss and also hammer forged barrel and i cant feel anything going past it.just sayin

Barrels
 

When I’ve lead slugged barrels I can at times feel the front sight from the dovetail machining process, but I’ve not noticed the rear one before. You can often feel the beginning and ending of some factory issued barrel fluting as well.
The fact that you can feel it during cleaning is likely significant, has accuracy been an issue?

Take a look with a borescope, and see what you can see. Maybe you’re coming out of a carbon build up in the bore?

Then run an air gauge on the barrel that’ll cypher out more.

But
At the end of the day, how does it shoot?

If the accuracy is fine, it’s just one of those things..... you really can’t do much about it (short of re barreling) and who says you’ll get any better results with anything new........

Yes it shoots ok, i dont use a scope on it and im not real concerned about it. I dont mave my borecam handy but im pretty sure its not carbon. Its odd though, and i wonder if other 527 have this problem because of barrel stresses and the dianeter lump at the rear site or maybe its some other cause just happen to be at the rear sight by coincidence.