I've posted photos before of my friend's StG45, and tonight I persuaded him to let me shoot it (not much persuasion required, I just asked to take it to the range 
). I wasn't really shooting for accuracy, but managed to put five rounds offhand into about a 4-inch group at 50 yards (with Prvi Partisan 8x33mm). Not great, but the rifle will definitely do better if you let it.
The two things that really struck me were first, how well the rifle shouldered and second, how really pleasant it was to shoot. Bringing it up into a shooting stance seemed to plunk the sight right in line with my eye, and the cheek weld was great. The recoil was very light, and very long. Instead of the sharp impact of an AK (for example), the StG produced this slow and soft push. Followup shots were super easy, because your hardly lost the sight picture at all when firing. If they were actually commercially available, they would be the ultimate new-shooter rifle.
After we got back from the range, I started pestering my friend with questions about how the thing worked, and the result was that we stripped it down and took a bunch of pictures. The more I learned about this weapon, the more and more impressed I was.
First of all, the bloody thing only has eight parts, excluding the trigger mechanism! Disassembly is done by pushing out a pin at the rear of the receiver, which allows the stock to slide off. Actually, it allows the mainspring to launch the stock across your living room, but that's another matter.
Once the stock is off, the mainspring, bolt/bolt carrier assembly, and dust cover come out, along with the bolt handle (which is held in place rather like a Daewoo or 1919; you pull it out to allow the bolt carrier out of the receiver).
The long tail on the bolt carrier acts as the guide for the mainspring.
The gun operates with a roller-locking action, so the front end is extremely simple. The barrel is pressed into the front trunnion and pinned (like an AK barrel is), and the trunnion is welded to the receiver shell.
There are no gas ports, pistons, tubes, or anything else up front. The handguard is just a tube to keep the shooter's hand away from the heat of the barrel. Instead, the lockup is accomplished by having the two rollers on the bolt press against locking shoulders in the front trunnion and against inclined surfaces on the firing pin body:
The force from firing holds those rollers in place long enough for the pressure to drop to safe levels, and then allows the bolt and bolt carrier to cycle backwards.
There are lots of little details in the design that are really neat. The bolt is held onto the bolt carrier in such a way that it cannot come off when in the rifle, but need only be gently rotated 180 degrees to be removed for cleaning. The only tool needed for disassembly is a cartridge (or punch, screwdriver, pen, bayonet tip, etc) to pop out the single pin. The dust cover can be rotated to completely close up the receiver, and the bolt handle will rotate it back open automatically if you fire the rifle with it closed. The controls are all very ergonomically placed, and the mag release is huge compared to other guns (literally the size of a dime).
The receiver, handguard, dust cover, stock extension, sight tower, and trigger are all made from stamped sheet metal, and combined with the very simple operating system, this would be an extremely cheap rifle to manufacture. In addition, the operating system only requires four parts (the bolt face, rollers, front trunnion, and barrel) to be made of high-strength steel; everything else can be made with whatever grade of metal is available.
All in all a fascinating design, and a very surprisingly effective weapon given its manufacturing cost and appearance.
). I wasn't really shooting for accuracy, but managed to put five rounds offhand into about a 4-inch group at 50 yards (with Prvi Partisan 8x33mm). Not great, but the rifle will definitely do better if you let it. The two things that really struck me were first, how well the rifle shouldered and second, how really pleasant it was to shoot. Bringing it up into a shooting stance seemed to plunk the sight right in line with my eye, and the cheek weld was great. The recoil was very light, and very long. Instead of the sharp impact of an AK (for example), the StG produced this slow and soft push. Followup shots were super easy, because your hardly lost the sight picture at all when firing. If they were actually commercially available, they would be the ultimate new-shooter rifle.
After we got back from the range, I started pestering my friend with questions about how the thing worked, and the result was that we stripped it down and took a bunch of pictures. The more I learned about this weapon, the more and more impressed I was.
First of all, the bloody thing only has eight parts, excluding the trigger mechanism! Disassembly is done by pushing out a pin at the rear of the receiver, which allows the stock to slide off. Actually, it allows the mainspring to launch the stock across your living room, but that's another matter.
Once the stock is off, the mainspring, bolt/bolt carrier assembly, and dust cover come out, along with the bolt handle (which is held in place rather like a Daewoo or 1919; you pull it out to allow the bolt carrier out of the receiver).
The long tail on the bolt carrier acts as the guide for the mainspring.
The gun operates with a roller-locking action, so the front end is extremely simple. The barrel is pressed into the front trunnion and pinned (like an AK barrel is), and the trunnion is welded to the receiver shell.
There are no gas ports, pistons, tubes, or anything else up front. The handguard is just a tube to keep the shooter's hand away from the heat of the barrel. Instead, the lockup is accomplished by having the two rollers on the bolt press against locking shoulders in the front trunnion and against inclined surfaces on the firing pin body:
The force from firing holds those rollers in place long enough for the pressure to drop to safe levels, and then allows the bolt and bolt carrier to cycle backwards.
There are lots of little details in the design that are really neat. The bolt is held onto the bolt carrier in such a way that it cannot come off when in the rifle, but need only be gently rotated 180 degrees to be removed for cleaning. The only tool needed for disassembly is a cartridge (or punch, screwdriver, pen, bayonet tip, etc) to pop out the single pin. The dust cover can be rotated to completely close up the receiver, and the bolt handle will rotate it back open automatically if you fire the rifle with it closed. The controls are all very ergonomically placed, and the mag release is huge compared to other guns (literally the size of a dime).
The receiver, handguard, dust cover, stock extension, sight tower, and trigger are all made from stamped sheet metal, and combined with the very simple operating system, this would be an extremely cheap rifle to manufacture. In addition, the operating system only requires four parts (the bolt face, rollers, front trunnion, and barrel) to be made of high-strength steel; everything else can be made with whatever grade of metal is available.
All in all a fascinating design, and a very surprisingly effective weapon given its manufacturing cost and appearance.
