Some methods use impact to retract the locking bolt, most of which are destructive.
个别方法利用冲击力来使锁闸缩回，但大多数都会令材料解体。
The locking bolt is provided with an outer thread mating with the expansion pipe at the peripheral surface and has a groove at one end.
一锁定螺栓，其周面上具有与膨胀管相匹配的外螺纹，并在其一端设有凹槽。
The BRG-15 had conventional, gas operated action with rotating bolt, locking into the barrel extension.
该担心现有- 15接受传统，燃气经营与旋转螺栓行动，延长锁入桶。
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