Received my CMMG .22 conversion kit and two 25 rd magazines today from Black Dog Machine. Ordered Tuesday Probably heading out tomorrow to dump a couple hundred rounds through one of the ARs. Best part is that I get to shoot the hell out of my AR and it will only cost me about $5 in ammo Question ... I have a 'dedicated' upper I'm going to use with this (had a spare barrel from another upper I built, put the barrel in a spare stripped upper, etc...) so I don't need a gas system on this upper. Does it make sense to plug/block the gas port? I was thinking about some JBWeld in the gas tube hole in the front sight base. That way there is no permanent change to the barrel. I can switch out the front site base and turn it back into a standard 5.56 upper if I wanted, but for now it removes unnecessary components and keeps all the .22lr carbon fouling out of the chamber.