The Ithica NID 4E below sounds very much like the handling dynamics of some of the RBL's above. It works well for me. Anyone going to have such a gun at the VC? I'd love to measure it.

Ithaca NID 4E BLE Trap #457465 SST w/ CSMC 1 1/2"pad + 5/8" spacer: Weight = 9# 2 oz, balance = 5 1/2" to trigger, unmounted swing effort = 2.95, mounted swing effort = 11.73, half weight radius = 12.24, guage = 12, bbl length = 32", LOP = 15 5/8"