Doesn't really add up Mr. A.

Had this been done as a bore rifle from the factory it would likely have started as standard tubes first, rifled, then profiled. It would have been struck so as to have thicker muzzles than a bird barrel.

It would then have been regulated with whatever the customer wanted as a slug load.

Any number of competent gunsmiths then as now can cut rifle a bird barrel. The wisdom of that is debatable. Winchester would certainly do that on the orders of the head honcho, the question is 'did they?'.

The serial number is 'possibly' correct for the 1930's, but as we know nothing is always with M21's.

It's an outside possibility that what you've been told is true, but it's a longshot in my humble opinion.


"The price of good shotgunnery is constant practice" - Fred Kimble