452/455 DIRTY BROWN BORE AND BARREL

[Madcap]

What is that brown crud that's so difficult to clean inside the bores? The exterior barrels have it also but is easier to eventually clean.

[bamajoey]

It is nothing to worry about. Pull several patches through, then go shoot it. It's residue left from the bluing process.

[Madcap]

It is nothing to worry about. Pull several patches through, then go shoot it. It's residue left from the bluing process.

Never experienced anything like that stuff before. I put several brushes and patches through a NIB 452 Trainer and it's still there.

[Wiley Coyote]

LOL, reminds me of a Colt .45 ACP Gov't Model I bought off a guy a few years back. He'd buried it in preparation for Y2K and left it. It was packed in Cosmoline that had long since dried and I spent two weeks getting all of that off. About all I didn't try was boiling it in Acetone!

[Madcap]

I sent a question about it to CZ-USA the reply  appears to support what various other rifle owners mentioned:

"....The barrels are coated in a preservative grease prior to leaving the factory and are also blued(which is a type of rust) which can lead to that discoloration on the barrel surface from those two things.

A few patches should remove enough from the barrel to safely fire as long as they come out dry, but some residue will remain in pores for a while, which is normal and should not cause any safety, functional, or accuracy issues.

If you have any further questions or concerns please let us know and we will do our best to assist you.

Thank you,

Randal Stroud
Technical Support/Gunsmith Rifle Supervisor
CZ-USA
1-800-955-4486 x4706