American Handgunner May/June 1977

Here barrel is full forward, fired case in air just above muzzle, andfresh round in position for feeding into chamber on rearward stroke.its spring, scooping a fresh round from themagazine. The LM-4 works the same way,but manually.Mechanically, the LM-4 is quite simple.The barrel-cum-slide rides in tracks onthe frame and has an integral rearward extensionlaying alongside the fixed standingbreech. A sturdy extractor is fitted to thebreech, which houses a short, reciprocatingstriker powered by a torsionspring. The trigger is pivoted to the frameand connected to its lower limb is a barlaying in the left side of the frame. Therear of this bar contacts a roller on theside of the striker. A lug on the triggeraligns with a notch in the barrel when thebarrel is in battery. The magazine ridesmore or less vertically inside the grip.When the trigger is pulled the barmoves rearward, pushing back the strikerto compress its spring At the properpoint, the bar cams off the striker which isdriven forward to fire the cartridge. Also,as the trigger rotates rearward, it rotates asegment of the locking pin in front of anabutment on the barrel; at the instant offiring, the mechanism is fully locked, butunlocks when the trigger is released.Moving the barrel forward leaves thefired case held against the breech by theextractor. A lug on the barrel extensioncontacts the head of the top cartridge inthe magazine, pushing it forward aboutone inch; a second lug there strikes thehead of the fired case just before the barrelreaches the end of its forward stroke,and hurls the case clear.As the barrel is moved.back, a ramp beneaththe chamber scoops up the nextcartridge, and as barrel movement continues,the cartridge is chambered andpushed under the extractor claw. Whenthe barrel halts against the standingbreech, the gun is again ready to fire.Unless the barrel is fully in battery thegun cannot be fired; the lug on the triggerprevents pulling the trigger until the notch(Continued on page 70)Massive extractor hook in rightside of standing breech engagescase rim securely. Here cartridgeis shown almost fully chambered.