A guy a worked for had an electric impact gun fitted with a nifty drill
chuck: half inch capacity drill chuck and a 1/2" square drive. I'd
assemble trailers with the impact gun, have a suitable drill in the
chuck for the holes that didn't quite line up. Really nice to have the
gun switch to impact mode when it jammed up.

Anyone know where to get such a chuck these days? (Horrible Freight has
a sale on the impact gun)

I suppose I could make an adapter by turning a suitable taper on a 1/2"
drive socket or extension but.............