for a pump best to have at a slide frame then its easy mod so you can have slam-fire, though it is possible to mod a hinge frame to do the same though it needs a bit more machining.
heres a couple of pumps ive done, both with slam fire mod, the 1st is a 1off custom halfblocked orracle wih slide frame, the 2nd a standard 2000 cocker with the hinge frame mod
http://s16.photobucket.com/albums/b9/renie666/?action=view¤t=IMG_1033.jpg
http://s16.photobucket.com/albums/b9/renie666/?action=view¤t=IMG_1035.jpg
http://s16.photobucket.com/albums/b9/renie666/?action=view¤t=pump1-1.jpg
heres a couple of pumps ive done, both with slam fire mod, the 1st is a 1off custom halfblocked orracle wih slide frame, the 2nd a standard 2000 cocker with the hinge frame mod
http://s16.photobucket.com/albums/b9/renie666/?action=view¤t=IMG_1033.jpg
http://s16.photobucket.com/albums/b9/renie666/?action=view¤t=IMG_1035.jpg
http://s16.photobucket.com/albums/b9/renie666/?action=view¤t=pump1-1.jpg