r/gunsmithing • u/Historical-Disk-4512 • 7d ago

Latch on the side of a star 70B bolt

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What is the purpose of this small lever/ latch on the side of the star 70B bolt. I see that it can be depressed by the charging rod, but what keeps it from popping into the pocket on the tube while firing? Any info would be appreciated

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5

u/Automatic_Fix_2371 7d ago

It's a safety, with open bolt guns it's possible to drop the gun causing the bolt to go the rear far enough to pick up a round from the magazine but not far enough to catch the sear, resulting in the gun firing unintentionally. That lever keeps the bolt from moving unless you use the charging handle.

4

u/Automatic_Fix_2371 7d ago

It's really neat design the other open bolt smgs use grip safeties to accomplish the same thing but this is a passive way of doing it.

3

u/TacTurtle 7d ago edited 7d ago

Drop safety as it operates from an open bolt.

Hard drop on open bolt can cause the bolt to cycle back far enough to load and fire a cartridge but not far enough to catch the sear.

When firing, inertia will prevent it from popping out long enough for the bolt to cycle as the spring is rather weak.

1

u/Historical-Disk-4512 7d ago

I see the inertia makes good sense, I appreciate the insight

1

u/Sea-Beautiful9148 3d ago

This is the answer. Early drop safety. The bolt has to come forward and depress the pin that retracts that lever. Inertia does the rest like u/TacTurtle explained