I went a slightly different route, picking up a surplus Swedish M/21 B.A.R. also chambered in the 6,5x55mm cartridge you describe and which so favourable impresses us both. Though the barrel was plugged when obtained, once the 1968 amnesty came around it received a new .30-06 barrel from a M1918A2 BAR, courtesy of a local Air National Guard armorer. But I always wondered how it would do in the original chambering.
About a decade back, I found a like-new Swedish BAR barrel for $75 at a gun show, and restored the old shooter to its original chambering, and to the configuration in which it most likely served some Finnish gunner during the 1939-40 *Winter War* after the Russians invaded Finland in November, 1939. The Finnish *SA in a rectangle* is one clue to that probable use; so are the bloodstain discolourations across one side of the stock and receiver. Some 65 years after it's time of service, it remains a superb instrument.
