Why is the RT pro front grip threaded at the bottom?

[Aegis]

Can't think of a reason for the grip tohave what looks like a 1/4-20 threaded hole in the bottom. it is not a gas through.

[ß?µ£ §mµ®ƒ]

hmm my RTpro that i just got came with an Xvalve LX and a odd front grip (has grip pattern ) that can be screwed in and out cause its a gas through no clue what your grip is (perhaps the older grip with the 3 finger grooves in the front) it might be to hold something such as a screw in barrel plug?

[TheTramp]

It's because the foregrip used to be a gas through when they were put on the old RTs. The top no longer has a threaded hole to allow you to run a line to your valve but AGD probably had a lot of the bottoms already threaded so they just kept using them.