out-of-battery

Adjective

not-comparable

(weaponry) In firearms and artillery, having a condition in which a live round is at least partially in the firing chamber and capable of being fired, but is not properly secured by the usual mechanism of that particular weapon.

Japanese Meaning

武器、特に火器や大砲において、発射室内に生弾が部分的に存在し、発射可能な状態にあるが、通常の固定機構によって正しく固定されていない状態を指す。

What is this buttons?

During the safety check, the armorer noticed the rifle was out-of-battery, a dangerous condition where a live round was partly in the chamber and not properly secured.

Google Translation / DeepL Translation

安全点検中、整備兵はライフルが薬室に完全に収まっておらず、生弾が部分的に薬室に入って適切に固定されていないという危険な状態であることに気付いた。

Details

Sense（1）