That's the Hill design of the 1950s, which positions the cartridges in a magazine with the bullet pointed 90º from the receiver, with a *turntable* plate repositioning them as the bolt reciprocates. The Russians also have a design that predates the H&K effort, and a couple of other pistol caliber versions are around, as their ammunition's relatively short overall length makes the layout very usable in that application.
Assault Weapons Ban or not, I've got a couple of applications and possible uses for a SAW, and the layout of the Australian F89 is about as credable as anthing done with the basic FN Minimi as anywhere else. But the new Navy version in 7,62 NATO has possibilities, as do a couple of other SAWs, including the Bren-configuration or beltfed Robinson M96, the Israeli Negev and the South African S77. It sure would be nice to have one that'd feed from either side, allowing a twin-gun vehicle mount....
As to the spencer I really love mine. My collection of service rifles is from civil war era to current issue. With AWB in place my collection may be agumented with an accurate Airsoft display of the next selection vs the real thang.
I've got most of the XX Century covered, with a few odd sorts from before that, but figure any future developments will come my way if really needed. I've got a couple of Airsoft handguns around leftover from a project involving Crimson Trace laserpointer grips and holsters, and a couple of bullpups from configuration studies trying to improve the breed. There's still a lot of work to be done in that line.
-archy-/-
As to the spencer I really love mine. My collection of service rifles is from civil war era to current issue. With AWB in place my collection may be agumented with an accurate Airsoft display of the next selection vs the real thang. Stay Safe Archy !