Which term corresponds to the M240B locking system?

Which term corresponds to the M240B locking system?

• A. Lowering bolt
• B. Gas blast, auto only
• C. 1100M
• D. Blocks the sear

Answer: (A)

The locking system is described as a lowering bolt. In the M240B, as the bolt carrier moves forward and engages, the bolt is positioned so that it lowers into the locking recesses, securing the breech for the high-pressure portion of the firing cycle. This movement—the bolt “lowering” into place—provides the mechanical lock that keeps the bolt closed while the round is fired. The other options aren’t about the locking arrangement: one references the gas system’s behavior, another is a distance, and the last describes a function related to the sear rather than how the bolt locks.

The locking system is described as a lowering bolt. In the M240B, as the bolt carrier moves forward and engages, the bolt is positioned so that it lowers into the locking recesses, securing the breech for the high-pressure portion of the firing cycle. This movement—the bolt “lowering” into place—provides the mechanical lock that keeps the bolt closed while the round is fired. The other options aren’t about the locking arrangement: one references the gas system’s behavior, another is a distance, and the last describes a function related to the sear rather than how the bolt locks.