The "X" guns use button rifling just like Savage does. I see no issues with cast bullets.
As far as the "remington" Marlins, I guess it would depend on who your local shop gets the gun from. Some Wholesalers may have old stock and you could get a Conn. Marlin. All 4 of my "X" guns were made in Conn., so I can't speak personally to any Remington QC issues.
As far as the "remington" Marlins, I guess it would depend on who your local shop gets the gun from. Some Wholesalers may have old stock and you could get a Conn. Marlin. All 4 of my "X" guns were made in Conn., so I can't speak personally to any Remington QC issues.