Original sentence: On the other hand, the simplicity of the mechanism in the AR-7 has caused some consternation for range operators, since the bolt does not lock back at any point.Some range operators recommend placing a spent casing in front of the bolt to hold it slightly open so that the chamber is visible.The AR-7 is a light firearm and must be positively shouldered for reliable blowback operation.The rifle functions as a blowback semi-automatic.The spring then pushes the bolt forward, automatically loading another cartridge from the magazine for every pull of the trigger until the ammunition supply is exhausted.This is a time-tested, simple, and very reliable operating system for a firearm which is expected to see use in less than desirable conditions.This means the force of the fired cartridge will push the bolt backwards against a spring, ejecting the fired cartridge case.This means there is no easy way to demonstrate the weapon is in a safe, unloaded state without manually holding the bolt back
Edited sentence: 22 rifles, the AR-7 bolt cannot be locked open.Blowback is a time-tested, simple, and very reliable operating system for a firearm which is expected to see use in less than desirable conditions.In common with many blowback.The AR-7 functions as a blowback semi-automatic.The AR-7 is a light firearm with heavy bolt and twin recoil springs and must be firmly held for reliable blowback operation.The inertia of the bolt, twin recoil springs, firing hammer and its spring, relative to the weight of the bullet, delays opening of the bolt until the bullet has left the barrel.The recoil springs then push the bolt forward, automatically loading another cartridge from the magazine for every pull of the trigger until the ammunition supply is exhausted.The residual gas pressure pushs the fired cartridge case backwards against the resistance of the springs, opening the bolt, recocking the hammer and ejecting the case.The yellow plastic flag for CMP range use is recommended or a spent cartridge case can be used.To demonstrate the weapon is in a safe unloaded state, firing range operators recommend using an open bolt indicator to prop the bolt open so that the chamber is visible