Jerry, distance yoke to anvil (the bearing ball which the indicator plunger contacts) is 17" so it will plumb a 32" barrel from either end and overreach center 1" in theory. Hard to sculpt the yoke to avoid contact with some rib extension guns (16 and 20 ga.) so practically it reaches centerpt. on 32" from breech end. Might be a small "blind" spot on a 34" inch trap barrel with a Kerstner fastening; I can't remember. The conical stop collar does have to be removed or the depth is limited to approx. 15 1/2" depth on a 12 ga. I could do so by removing the setscrew in yoke, pulling the rod so that collar can slide off and replacing the rod in the yoke but have never felt the need as I have only 27<30" barrels with the exception of a 34" SBT. Graduations on the internal bar are ruffnready (MagicMarker tics at inch increments). As Christine points out, it also has the Gaddy "spring". Have closeup which I will post.
jack
