... the holes milled in the barrel extension... ...to show the vertical travel of the locking piece... ...make for an excellent visualization... ...thanks for posting...
Bolt, bolt accelerator, and a locking piece. Pretty simple. The bolt is quite massive, so a bolt carrier isn't an option - that piece has to be even more massive than the bolt. Neat design by John Browning.
At 0:17 the mechanism stops with the bolt, barrel extension etc. not fully in their forward position. About 1/2" from fully forward. Thus the extractor arm does not latch onto a fresh round to pull out of the belt. I assume this is either "operator error" or a badly operating display mechanism, but the result is actually fortuitous, as we can see -- as the locking block is almost fully raised by its cam in the floor of the receiver -- how closely the locking block pin is following the cam surface of the unlocking finger. There is not a lot of free play between cammed up and cammed down. If the display model had not jammed or stopped in this position, the movement of these parts through this phase of operation is too rapid to see. The firing pin or striker sear is visible sticking up at the very back of the bolt, and I note that the trigger bar is designed so its angled cam surface can't ever contact the sear unless the bolt and barrel extension and all are very nearly into their forward position. In other words, it is not a possibility to set the timing so advanced that the round could be fired out of battery. Right at 0:17 we can see the locking block virtually all the way up already, yet the sear is still almost 1/2 inch behind the cam surface of the trigger bar. When these guns "blow up" and bulge the side plates, it is usually due to the barrel not being screwed in all the way, and the head of the cartridge therefore being inadequately supported. I apologize if I'm not using all the 100% official terms for these parts. Aberdeen was a long time ago for me.
I hope to get an answer.. What is the benefit of the lock or the small latch inside the extension of the barrel? Why is it called a lock on which part it closes? Please answer.. Thank you
There is a vertically-sliding locking block in the barrel extension that positively locks the bolt into the extension (and against the breech of the barrel) during firing. In exactly the same way that the locking block of a Marlin or Winchester .30-30 lever-action rifle locks the bolt into the receiver of those rifles.
@@Fuzzybeanerizer Thank you, my friend. What is meant by the screw? I have a lot of information about the weapon, so I started to delve deeper into the question. Everything I know except the work of the shutter, I did not get to know it.
Most annoying the about the m2, is the fact that the bolt gets stuck to the rear. Could be the grease they use but I am still trying to figure that out.. Breech lock is supposably responsible but doesn't seem like it...
