There are times when the working action of a modelgun needs checking over, correct feeding and extraction of cartridges for example.
Sometimes it's easier to do this without actually firing a cap.
As dry firing without cartridges isn't recommended for any modelgun (or real ones come to that) what I do is assemble cartridges with "dead" i.e. previously fired caps.
That way, the modelgun will feed a round, push the cartridge piston towards the dead cap and the firing pin can push the "primer" as intended.
As there's no charge in the cap, the modelgun can be hand cycled to extract and eject the cartridge without risking damaging anything.
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Cerwyn
Hobby collector of Replica model guns and Militaria.
also member of Living History Reenactment Groups.