Grease groove in WWII .303 bullets important or not ?

[Bruce_in_Oz]

Thanks, BombDoc.

Only saw a Vickers barrel swap in a workshop, once; long ago and far away.

I spent a lot of time both firing and fixing the good-old M-60, which also had / has a "Stellite" insert. The REALLY flogged out ones that were used to make "Blank Firing" barrels, usually had quite good-looking throats / leades, (Stellite), but were often virtual smooth-bores beyond that; NOT to be used for overhead live fire. Talk about getting your money's worth out of a barrel!

Never saw a liner come loose. There is a small gap between the stellite bit and the nominally hard-chromed remainder of the bore. I figured that this was to allow for a difference in the expansion characteristics of the two materials.

When we had to "de-mil" M-60 barrels, the liner was a challenge; the gas-axe just bounced off and the "drop-saw" with the nastiest abrasive wheel was not terrible effective. One trick was to cut around the circumference, down to the liner, and then attempt to shatter it by bashing it with a BIG hammer. Eventually, it was decided that if the locking collar was destroyed and the barrel forward of the stellite cut into short pieces, it could be considered "innocuous" enough to go in the "controlled scrap" bin. If that stuff ever went near a smelter, the stellite could have been a cause of annoyance to the operator.