The Remington barrel is a liitle odd
Not odd in the least, its quite common to find mixes between receiver and barrels.
During the war, (and after storage) damaged barrels would be replaced with barrels pulled off of damaged rifles, parts is parts.

The couple years post WWI found millions of the M1917 rifles improperly stored, turning into piles of rust (after rebuild no less) so they had to dismantle a good percentage of the rifles to re rebuild them and more mixing happened then (and more parts went to the trash can).

Dan