Variants
Although the M1 is the mostly frequently encountered version, there is also the M1A1 paratrooper Carbine with folding stock, the select-fire M2 Carbine and the M3 carbine which was an M2 carbine with the M2 infrared night sight or “sniperscope.” The M3 did not have iron sights. The sole manufacturer of the M1A1 paratrooper Carbine was Inland.
The last M1 model produced had several improvements over previous models, including: adjustable rear sight instead of the earlier “L” flip sight, Type 3 barrel band incorporating a bayonet lug and a round bolt versus the earlier flat bolt.
Early models had push-button safeties but on the later versions, a lever replaced the button. The change was made because of reports soldiers were accidentally hitting the push-button mag release when taking off the safety in preparation to fire — not a good thing. I have both types on personal carbines and have no real preference for either type. With the push button, push to the left for “fire” and to the right for “safe.” With the lever, rotate it to the rear for “fire” and straight down for “safe.”
The rear of the stock has a slot cut into it for attaching a sling. The sling is held in place with an oiler; a cylindrical tube, and the screw-on cap has a small dipstick to apply lube.
By contemporary standards, the sights are hard to pick up quickly. But the small aperture on the rear sight offers a very fine sight picture and is capable of good accuracy. The rear sight is adjustable for windage via a knob on the right side. Elevation gradations are set nominally for 100, 200, 250 and 300 yards. The front sight is not adjustable and consists of a 0.086″-wide blade. Both sights are protected by wings.
The most commonly encountered magazine supplied with the carbine is a 15-rounder that does not lock the bolt to the rear when the last shot is fired. I have seen some M1s with an M2 mag catch for use with 30-round “banana clip” magazines. If so equipped, the bolt will lock back after the last shot is fired with the 30-round mag.
A button on the charging handle manually accomplishes locking the bolt to the rear for administrative purposes. When the charging handle is pulled to the rear, push the button and it will lock into a corresponding slot on the receiver. To release, simply pull back on the charging handle and let it go home under spring pressure.