I made a "practice fixture" for Karl and me to work with the Avery back riveter. Did one row of 3-3.5 rivets on one inboard rib, Karl working the cylindrical bucking bar, me on the gun. Only two rivets at the bottom were pushed out by the backriveter and had to be re-done.
We then practiced with the mushroom set and bucking bar. Re-did the last two rivets, Karl on the gun, me on the bucking bar.
I think the mushroom set (pivoting!) and bucking bar does the better job. Kind of awkward to get the double offset back riveter straight-on to the rivet shank.
