19 yrs ago, At the NMLRA EAatern, I purchased a custom rifle from a fella that had spent too much and needed cash to get back home to New England. It has a tapered (but not swamped) 40 inch 50 cal barrel with peculiar rifling. The grooves are round bottomed and just slightly wider than the lands. I can't find any identifying marks on the gun or barrel as to maker, even of the parts. I had a custom barrel made by H&H back around 1979 and they used a round bottom rifling, but the grooves were twice as wide as the lands. And to my knowledge they didn't make tapered barrels. Can anyone tell me of other barrel makers that used round bottomed grooves in rifling?