DD

Thanks for the update... yes, the .256 Win Mag is basically a .357 Mag case necked down to .25 cal with a 25 degree shoulder, good for ~2400fps with a 60gr bullet.

The .256 Max is essentially the same, but based on the longer .357 Maximum case.

Sportco in Australia bought up many thousands of ex-military .310 Cadet Martinis (mainly BSA, some Greener) and were then 'reconditioned' by surface grinding off all the serial numbers, unit and proof marks from the already thin walled actions, and rebarrelling them to .22RF, .22 Hornet, .25/20 and .32/20 in the early post WWII years when ex-military .303's were illegal for private citizens to own in some states.

They also fitted a rudimentary 'cross bolt' safety behind the trigger... not needed IMO, but perhaps required in order to sell to the public even in the 1950's.

http://www.sportco.org.au/intro.htm
http://www.sportco.org.au/models.htm

The breechblock below is from an ex-Sportco converted .22RF... note the off centre hole for the replacement Sportco rimfire pin. Someone has since converted it back to CF by dropping in a standard .310 firing pin.

Overseas Francotte Martinis and the BSA thickwall Martinis like the 1215 may well have central RF firing pins, but the Sportco converted ones I have seen here in Australia were all off centre... I'd say this is where the confusion arises, as quite a few converted Sportco Martinis have ended up in the USA