I thought you guys might like to see this, although it's a wee bit off topic. No personal arm has used the feed cycle of the Mauser MG 213...until now. If you're not yet familiar with this Nazi prototype, it worked like this:
I found out about the MG 213 and related designs about halfway through my build, when I was about done testing the gas ejection cycle in 357Magnum. Magazine feeding in 357 was impossible due to the shell width, which is why I converted to 9mm - those rounds are narrow enough to slip through the new hole right through the guts of the gun, and since the 9mm is less potent than the 357, the stresses on the somewhat weakened frame were reduced.
Anyways. Thought you'd want to see a genuine working home-built model of this design that is still lethal .
This is the first personal arm ever that has the same feed cycle as a WW2 Mauser MG 213...a hybrid with features of both a revolver and a gas-operated autoloader.
This also show why the US Pontiac M39 derivative of the Mauser had a great rep for reliability: the feed path is straight rather than bent as most autoloaders are.