Just bought a bullpup shotgun. G Force GYF-1. Does anyone have one, or have a bullpup shotgun similar to it?
I'm having this problem with the gas piston, it moves back and forth when manually racking the shotgun. Is it suppose to do that?
Have you broken it in yet? The website FAQ for GF says to use shells with 1400fps or higher velocity until it's broken in. Thereafter, use 1350fps or higher. That's not related, but I'm curious if you've shot it to test functionality, or have only noticed the piston moving while operating it at home.
The piston is free to slide along the barrel if the spring & action bar are retracted. I see no reason to worry if it's moving when you manually cycle it since that's the same as when it cycles when fired.
i would be more concerned if you pull back the charging handle and the piston doesn't move, It might be time to clean the barrel (externally), the piston and the piston housing (gas coupling).
I've read that debris from slug rounds can collect inside the gas coupling and jam the piston causing it to stop cycling at all. One owner said he had to use a torch to melt the lead trapping the piston in the coupling.
Hope that's helpful. I don't own the same gun. Only 12 ga bullpup I've had is the Keltec KSG-14 pump action.