Thanks.
Normal 760's have smoothbore barrels, but this one has a Crosman 1760 barrel machined to fit by Roy at Mountain Air custom airguns.
Like I said this was off hand, just sitting on the ground, no bench or rest, not even a field target position. With the smoothbore 760 the best I get is a pattern about 1.5" to 2" at 20yds! :)