I have a comment on the broken bolt.
The problem is caused by a bad recoil spring and or poor lubrication. The carbine will fire out of battery. If you look at the front bottom of receiver there will be a white line on receiver and a line on the back of bolt where the bolt is hitting the receiver. What happens when weapon is fired is the slide hits receiver and recoil spring does not have enough power to get the bolt back in battery and it recoils with no hesitation, cracks a bolt or jerks the ear completely off. I have had both happen. " But I am very careful to clean and oil my Carbine" I hear that all the time. Carbine runs on Grease not oil. Good rule of thumb is if it rotates oil it, if it slides Grease it. For those of you that thinks I am wrong? Take your favorite carbine out to the range load it up, pull the slide back about one half inch and fire it. Anyone wants to tell me how wrong I am email me at garys615@aol.com