I changed up the design of the foregrip, so that it is held in by 2 bolts instead of just 1. I honestly didn't think that 1 bolt would be that strong, and the recoil would probably cause it to crack. With it clamped down in 2 places, the stress is more evenly distributed. Also I hollowed out the middle part a bit to save plastic. I'd recommend printing this with PETG, ABS, Polycarbonate, or Nylon-X (my personal favorite).
Obviously when slicing, rotate the foregrip 90 degrees so the flat side is on the build plate... And preferably print with a brim and an enclosure (depending on the filament type) to prevent warping.
(2) M3x30mm screws
(2) M3 nuts