M60 Machine Gun Bolt

Angles of Entrance of Ammunition

The firing pin is carried forward by the breechblock slide key, attached to the breechblock slides, and by the force of the expanding driving spring. This action causes the firing pin to strike the primer and fire the cartridge. When the slides have rcachcd the end of their forward motion, the inertia blocks continue to move forward in their slots until they strike the forward end of the slots. This eliminates any tendency of the slides or firing pin to rebound.

During the automatic firing, the electric trigger on the Mod 4 or the scar release assembly on the Mod

5 holds the sear downward, away from the breechblock lock. This allows the breechblock to move through its cycle without being engaged and held in the cocked position.

To stop firing the Mod 4, the trigger switch is released, allowing the sear to be forced upward by pressure from the sear spring plunger and sear return spring. To stop firing the Mod 5, the manual firing lever is released, allowing the sear to be forced upward by pressure from the sear release block spring. The sear has an upward projection on its top surface which engages the recess in the breechblock lock, thus holding the breechblock in the retracted position.

When the cartridge is fired, pressure of the propel-lant gas in the gun barrel forces the machine gun to recoil in the following manner: the front recoil spring seat and the barrel move to the rear, compressing the recoil spring until the rear of the front rccoil spring seat contacts the front of the rear recoil spring seat. This contact prevents further compression of the recoil spring.

In this first phase of recoil, the recoil spring has absorbed part of the shock. The rear of the rear recoil spring seat is in contact with the front follower of the recoil housing assembly. The rear of the follower is adjacent to the front of the ring spring in the recoil housing assembly. The remaining shock of recoil is thereby transmitted to the ring spring. While the ring spring is being compressed, the recoil spring

Coil Spring
Telescopes Mastery

Telescopes Mastery

Through this ebook, you are going to learn what you will need to know all about the telescopes that can provide a fun and rewarding hobby for you and your family!

Get My Free Ebook

Post a comment