FM 23-45 Basic Field Manual
15
When the breech lock clears the breech lock cam, it is forced down by the front
projections of the lock frame acting on the breech lock pin. This unlocks the bolt from
the barrel extension, permitting the bolt to continue to the rear. AS the barrel
extension comes to the rear, the barrel plunger spring is compressed, and the rear of
the barrel extension strikes the accelerator and turns it backward.
F
IGURE 9.—Relation of parts in forward position.
■30. B
ACKWARD ACTION OF ACCELERATOR (figs. 9 and 10).— AS the accelerator turns
backward its tips strike the bottom projections on the bolt and accelerate it to the rear.
F
IGURE 10.—Barrel, bolt, lock frame, and barrel extension in firing position.
The claws of the accelerator engage the shoulder of the T-lug and lock the barrel
extension to the lock frame. The barrel plunger spring is thus held compressed. The
accelerator stop prevents the accelerator from turning backward too far.
■31. B
ACKWARD MOVEMENT OF BOLT (figs. 9 and 11).—As the bolt moves backward the
driving spring is compressed. The bolt brings with it a cartridge from the belt, held by
the extractor, and an empty case from the chamber, held in the T-slot. The extractor
cam plunger rides along the top
F
IGURE 11.—Extracting and loading mechanism.
