Feed Ramp Issue

[Powderfinger61]

I was doing a customers pistol and while polishing the feed ramp this line appeared.
Anyone seen this before? It does go completely to the other side.
This barrel is from a Norinco NP22

 

[Aniest]

Yes... had a Norc 1911 9mm some time ago: had it until I shot the barrel out after countless rounds. I had polished the ramp as well. I believe the barrel is not a single forging, but a "tube" within the "block" and what you are seeing is the line where the hot "block" was put onto the cold "tube" and allowed to "shrink fit" onto it. It never caused a problem.

Sorry for the loose quotes, but the terms are likely not correct.

 

[trevj]

The barrel is inserted into a block of something else. That is a seam.

You honestly have never seen a lined barrel before?

 

[bearhunter]

This is quite normal for many semi auto firearms.

There was a Browning Hi Power on this site with pics of one of these barrels separating. Usually they are either sweated or silver soldered into place.

I can see why it's done that way. A casting or extruded bar can be cut to width, drilled appropriately and attached to a barrel stub without having to remove a lot of expensive material or include other high cost machining.