Remington, Winchester and Savage have chambered the 6.5x55 off and on. Pretty much any rifle could be rebarreled with a 6.5x55 barrel. Great cartridge, kills out of proportion to its paper ballistics.
I reload for6Mm and have never had a problem finding brass for it . everything else is the same components as the 243 Win takes as far as bullets and powder goes .
Not sure I understand what the 6mm Remington has to do with 6.5x55, though...