Carbine barrel dates

Do all carbine barrels have the date stamped on them? I can't seem to find any on my NPM or my Winchester.

Quick answer is no. Some did not date,others dated and some of the dated ones had trouble with their stamps and was partial dated or might have no date at all.

No, not every barrel is marked for date. Who made the barrel for your NPM?

On the NPM, it is a I B M barrel.

I.B.M. dated their barrels through 1943.