Originally Posted by ElJefe13
That is a major weakness to me. When I'm shooting FS, I really like to fire with a bipod.
Prepping the pump handle to add a picatinny rail is very cheap and easy. Simply add some epoxy into the hollow wells of the pump arm where the bolts will be, drill the holes through the pump arm and epoxy using the casting line (obvious center of the rounded body), then nut and bolt the picatinny rail to the pump arm. A Ruger 10/22 picatinny rail has a similar curve on the bottom compared to the pump, and bolted up without much gap at all.
The epoxy will give the nut a flat surface to press against; and will distribute the clamping force over a large area, keeping the bolt from potentially pulling out.