2-piper; I think you may be misinformed. The picture of Bo-Whoop no. 2 on the cover of "Mr. Buck, An Autobiography" shows a double trigger gun with a pistol grip....Bo-Whoop no. 1 was a straight grip gun which Nash preferred, but had no problem with the different stock style. Both Bo-Whoops were double trigger guns. Nash shot double guns, is pictured with a Merkel O/U .410, and shot pump guns in his long career; my point being, a shooter like Nash could use any style of shotgun and perform well with it. The original question concerned altering a Winchester 21 from single trigger to double trigger to hunt with at Beaver Dam....I would just be grateful for the opportunity to hunt in Nash Buckingham's footsteps with any duck gun I had.