I purchased mine this year and learned how to use it thanks to this web forum. I hang it horizontally from a water pipe in basement. Can then be slid into barrel and moved on pipe very easy (16" max.). Have to ajust to maintain level with barrel (can't let rods touch barrel wall)and don't read while touching gauge. I record every inch form breach on top, reset for side and bottom. Then do the same from muzzle. It's a long process but it works. The barrel is held off table by at least 16" using shot bags.
