During the 1930s, SIG Neuhausen made a series of really beautiful submachine guns. They were the MK series, offered in either 500mm / 19.7 inch barrels for military use or 300mm / 11.8 inch for police use. The first pattern was the MK-O, which had a rate-reducing system built into the action (which looks initially much like a delayed blowback system but isn’t). These proved too expensive, and a simplified plain high rate of fire model was introduced, the MK-S.
This example is a very rare factory semiautomatic model purchased and imported by Sam Cummings. The vast majority of the MK guns were fully automatic, but semiauto was a factory option, as police use was one of the intended markets.
Man, Swiss being Swiss… If the ”delayed bb action” actually is a ROF reducing system, why in god would you bother to add it to a semi-auto only? Just guessing, make me believe that it would be financially ”stupid” to change up the tooling and change the operating system to plain ”blowback” But hey, trying to understand some of the choices the Swiss made regarding their firearms is a whole other discussion.
Wow, not many of those ever made. I had no idea it was such a rarity. “Swiss quality … Swiss prices” is the take-away.
Most viewers are probably aware that having the very French-style magazine folding forward (also Hungarian 39.M and 43.M) not only makes for more compact carriage or portage, but also removes the ammo from the bolt raceway…an important safety feature with blowback SMGs.
The hoary-old Thomas B. Nelson tome on SMGs also thought the two-piece bolt mechanism was a blowback retarding system… But then noted that the MKMO military use fired only full-auto. So I’d wager Ian just might be spot on about it being a rate reducer. The same source thought the rpm was 900! Mighty fast. The military variant would have truly been a “maschinenkarabiner” at 1025mm/40-1/4-in. length and fully 4.7kg/11.5 pounds loaded weight!
The MKPO would shave things to 820mm/32.7-in. length and 4.37kg/10.3-lbs. weight. Contrast the lovely wood stock and lavish use of high-quality machining and metal finish on this graceful gun with the hideousness of the also-Swiss REXIM F.V. Mk.4, with its MAS-36 style spike bayonet and side-folding Sten-lookalike skeleton stock. Although the unlovely and unloved REXIM gun did fire from a closed bolt. It could also be had with enough variations of barrel length, with Thompson style compensator and cooling fins or without, with barrel. jacket or without, to satisfy the most jaded video game Call of Duty player.
These SIG Neuhausen maschinenkarabiner would really have lived up to the “carbine” moniker in the 9x25mm Mauser cartridge, no?
I love how the locking screws on the trigger guard also have scalloped cuts that seem to allow a third locking screw for the locking screws to be added !
As Ian showed in the video, the point of the crescent cutout in the locking screw is to allow the locked screw to be turned simply by aligning the locking screw to that position. Otherwise you’d have to back the locking screw out all the way.
Definitely has M50 Reising vibes.