Given the success of the double-ender in other industries we decided to take a stab at it. Works for both AR-15 and AR-10-size barrel extensions.
View attachment 193073
https://truenortharms.com/products/torkey-tool?variant=12228034330732
At first I was like how do you clamp that in the vise?? I've never thought to use it vertical before.
You could probably make the flat spot 6.5" so it will fit in a normal vise horizontally.