So I just picked up a pump mag with a rainman pump kit. It works well if you pump it using the pump handle, very short and smooth stroke but if you try to pump it using the hitman mod it binds up.
All I can tell is there is just too much play between the center guide rod and the pump handle.....
I have no experience with these so I may be missing something, any advice is appreciated.
Of course, a pic for good measure