Back of bolt smashing into back of reciever

[Clay]

Is it normal for the back of the bolt to smash into the back of the receiver. My gun is almost new so it will get worse. Also the top of the bolt seems to be gouging the top of the inside receiver. Please look at pic.

[Synchronizor]

I could go into details about exactly what causes those marks if you're interested in reading an essay, but the bottom line is that it's normal wear, and you don't need to worry. These marks show up pretty quickly on new 870s, but they won't keep developing at that rate. The rear dent on the receiver stud will stop growing completely after a certain point, and the top mark in the receiver will slow down a lot. Neither will affect the gun's function.

[Clay]

I would love to hear why those marks are there. Please explain. I have another 870 doing the same thing. But my 20ga 870 does not do this. I think the 20ga is a bit different. This all being said I have a sks that does something similar...........

[Synchronizor]

I'm busting my butt at the moment trying to get a draft of my thesis in for review, but once I get some free time I'll type up an explanation.

[rockyrider66]

I had the same observation with my new 870 Wingmaster at first, however it was suggested with shooting, cleaning and lubrication, this would all go away. All I can say is it is true. I am currently enjoying non intrusive shooting with scores in the twenties or near as a new trap shooter.