On/off gas block


With straight pull manual bolt action AR’s becoming a “thing” lately it would seem pretty convenient to have a gas block configured something like the M1A’s 90 degree valve. Trying to close up an adjustable block is too much of a PITA; they don’t always close all the way and getting it back to the sweet spot is waste of time and ammo. The icing on the cake (for me at least) would be top and bottom Pic rails like the GunTec.

Anybody else think this is good idea? Is there one out there already?