This is my New Rig I working on, it's far from completed. but you will see my idea.

Started with a MAC1 Tuned Disco
A Disco double tube kit.
Adjustable trigger grip from a 2240
Added a RVA
Scope is a ZOS 10-40X60 copy of Falcon T-50 <--- sorry.
Weaver style barrel rings. for installation of Front Grip and accessories.
Need New scope mounts and a read stock. I wanted to make a custom Skeleton rear stock But it's would be lots of work to get it to work with my
R.V.A. so maybe I will order a cheap bug buster or something similar.

This will be adjusted to 780fps for WFFT