Multi-pump hunting

[airgunner53]

So I have this old broken crosman legacy 1000 which is just a updated 2100 pumper. I took out the pump tube and piston assembly today, got to tinkering with it and figured out how to put a factory size 1377 valve into it. Had to drill a relocated exhaust port hole and the hole for the front grip screw and still need to drill the front tiny 4-40 breech screw and thread it. My next task is how to shorten the factory piston to fit now that the slightly longer 1377 valve is in the gun. Would it be easier to figure out how long it has to be to bottom out against the front of the valve and drill a new pivot pin hole in the pump lever and cut off the excess so it will go back into the end of the piston without binding? I'm looking for suggestions. Will moving the pivot hole make the gun harder or easier to pump? I can't wrap my math around that. I'm including pics, in one I tried to lay the piston beside the pump tube so you can see how much it needs to be shortened for it to fit. The other pic shows where and or how I may shorten the lever.View attachment 551832View attachment 551833
Thx
Ray

Might be less pumping effort due to reduced stroke.

 

[airgunner53]

So I have this old broken crosman legacy 1000 which is just a updated 2100 pumper. I took out the pump tube and piston assembly today, got to tinkering with it and figured out how to put a factory size 1377 valve into it. Had to drill a relocated exhaust port hole and the hole for the front grip screw and still need to drill the front tiny 4-40 breech screw and thread it. My next task is how to shorten the factory piston to fit now that the slightly longer 1377 valve is in the gun. Would it be easier to figure out how long it has to be to bottom out against the front of the valve and drill a new pivot pin hole in the pump lever and cut off the excess so it will go back into the end of the piston without binding? I'm looking for suggestions. Will moving the pivot hole make the gun harder or easier to pump? I can't wrap my math around that. I'm including pics, in one I tried to lay the piston beside the pump tube so you can see how much it needs to be shortened for it to fit. The other pic shows where and or how I may shorten the lever.View attachment 551832View attachment 551833
Thx
Ray

You ever get this build going. You may need to cut the piston and make it adjustable. Also, the old brass valves need their cone shaved down by about .030 because the cone will hit the cup before it's fully compressed reducing the pressure. I did this on my laithe but can be done by hand if needed. That would make a nice compact pumper hunting rig.