Well, I borrowed a camera with video, I tried, just not good enough to run an impact with each hand and not have one blow off the screw, sorry. Next time I'll use hex head screws, harder to screw up.
FWIW, I ran all I had, used the 'ol onethousandone, onethousandtwo count routine.....
Material: 2 pine 2x4's clamped to the bench
Screws: #9x3" long, no pilot hole, started by hand, appx 1/4" (6mm) in
Results:
Bosch ps40, 10 seconds
Bosch ps41, 5-6 seconds
Milwaukee M12, 8 seconds
Old DeWalt ni-cad, 12 volt, 4 seconds
Just for shrits & grins, Bosch ps21, 7 seconds.
Maybe I can get a compentent assistant, try the video thing again.
Pathetic as it my be, I did upload my attempt.
Ed
[flash=200,200]http://s143.photobucket.com/albums/r150/Ed_L64/?action=view¤t=P1020301.mp4[/flash]