A few years back I bought an unturned blank from Getz barrels and I'm finally getting to use it!! Trouble is ,it has 7 lands and grooves and my anvil mic has "wandered off". The two machine shops in town don't have one either, and I can't catch Don Getz in the office. Does anyone know the groove depth they use? It's a .50 cal, 1 in 28 twist, but the grooves seem shallower than average for a black powder rifle. Thanks in advance for ANY help.