[Surplus_Sam]

Upon cleaning K31, the barrel has a discolored spot. It is blacker than the barrel bluing and has some rust colored marking under the bluing. It is not pitted and there is no surface rust. Could something have been spilled on the barrel? A few pics attached. Thank you.

 

[Leon]

Does your K31 have a walnut stock? The location of the discolored area leads me to suspect it is from contact with some sort of shim material. The K31 barrel free floats but contacts the stock channel at the front, where it gets some upward pressure. Conceivably, the stock was warped and a shim was inserted to provide the missing contact. (I have a K31 with a walnut stock, which seems to be warped and/or shrunk, and it required redoing the bedding to get it to shoot the way we expect a K31 to shoot.)

 

[Surplus_Sam]

It is a beech stock. I did not see any type of shim. Is it only the K11 and 1911 that have the metal sleeve attached to the barrel?

 

[Leon]

I don't know if the M1889 and M1896 also have the barrel sleeve. The only thing I can go on is the location of the discoloration on your barrel and possibility of contact with acidic paper or card stock. Possibly a previous owner tried to enhance accuracy by placing some sort of shim material under the barrel. I bought an M1911 that had some strips of beer can aluminum jammed inside its barrel sleeve. Evidently its previous owner did not understand, or believe in, the concept of a fully free floating barrel.

 

[Surplus_Sam]

Do you think that spot could lead to rust?

 

[tacfoley2]

It is a beech stock. I did not see any type of shim. Is it only the K11 and 1911 that have the metal sleeve attached to the barrel?

So it seems.

tac

 

[Leon]

Do you think that spot could lead to rust?

It already has; bluing is a form of rust, and the area in question has undergone further chemical change. If there is no pitting or scaling of the metal, then more than likely the condition is stabile. Coat the barrel with a suitable protectant and leave it at that.

 

[Surplus_Sam]

A light coat of rig on the entire barrel?

 

[Leon]

A light coat of rig on the entire barrel?

While RIG is superb for long-term storage, I can't vouch for its effectiveness when subjected to high temperature. The K31 barrel does get quite hot when fired; it is not a particularly heavy barrel. The RIG may soften and drip. For my rifles I use a product called Tufoil Guncoat.

 

[Ronbo6]

Another possibility for long-term preservation would be to put a coat of wax on the barrel.

Most Automotive waxes should hold up reasonably well on that barrel. If the wax can withstand being out in the sun and rain on the outside of a car for weeks or months, being on metal protected by the stock should be pretty easy for it.

I have also used Johnson's Paste Wax (the stuff in the yellow can) on metal parts with good results.

 

[diopter]

Upon cleaning K31, the barrel has a discolored spot. It is blacker than the barrel bluing and has some rust colored marking under the bluing. It is not pitted and there is no surface rust. Could something have been spilled on the barrel? A few pics attached. Thank you. View attachment 757690 View attachment 757691 View attachment 757692

Maybe shellac. Try barrel soaking with alcohol.