Adjustable gas block or tube

[pug]

I think you are going to have to get something made either way. I shortened an adjustable carbine gas tube down for my first pistol by cutting and regrinding the bell on the end. I also have some custom blocks just no bull ones. A bull block will fit under a ff tube but may not be enough room to get an adjustment screw in there. The JP looks like it may fit if the rail is removed but no way to tell without actually measuring one.