Some rifles are very, very fussy. Back in the 1980s, I got a .270 from Joe Balickie that was built on one of the very rare left-handed Mauser actions that P.O. Ackley imported from Japan. It was a lovely gun, but it would not group. I shot it, and shot it, and shot it, but no dice. Then, in a frenzy of despair, I tried a powder called Hodgdon 205, which burned about like IMR 4350, and all of a sudden I could hit dimes with the rifle.