OK, I lapped the Mark II and just finished shooing it for the first time since it was re-born. I used the same protocol for shooting that I used for the rifle, except that this has open sights. (10 shot groups at 25 yards measured CTC; clean barrel between different ammo brands and then foul the barrel with 20 shots before shooting for groups)
I was considerably more impressed with this barrel than the Browning Composite on the Buckmark Rifle....it shot better before lapping and I was a little more hesitant to ruin what I had. I did not use any 220 grit on this barrel becasue I felt it was in better shape and might benefit from a less aggressive treatment. I did use 15 rounds of each other grit.

The groups are as follows: (First number is Pre Lap and 2nd number is Post Lap


Fed Bulk Ammo .931" .869"
Dynapoint .980" .505"
Wolf Match Target .575" .551

Average .829" .642

For a 22.6% increase in accuracy.