I did some grip swapping, pumps & autos share the mounting shape, up to a point.
There is a difference in length of pull, one or two fingers between end of receiver, and trigger guard.
The pistol grip has a kind of spacer, to take up this gap, I blue taped it, grind this off it would fit the auto.
Shoulder stock is too long for me, with the pump, I did shorten it 1 1/8 inches, it is too short with the auto.
Trigger hand hits my nose, but I can use the front sight, shoots a bit high, short range.
Different loading capacities, minis do shoot in the auto but don't cycle or jam, they work better in the pump.
Black powder signal cannon, bigger boom, 2 oz of boom juice recommended,

Someone left their targets, slightly vented, I left them fully flattened.
Drove into VOC and disgorged the mini for a mail run into Sedona, & dinner & Jose's Cafe,
Dang good muchaca omelet, this one thick with meat.
Havin' a good day, , ,