jimro, if one barrel with given twist doesn't shoot a given bullet well but another one with the same twist does with that bullet, it ain't the twist's fault. Something else is the problem. Differences between one system and another with something is caused by one or more parts in the one system being different than the other.
US Navy Distinguished Marksman Badge 153
Former US Navy & Palma Rifle Team Member
NRA High Power Master & Long Range High Master
NRA Smallbore Prone Master