About the .444 Marlin, some of the older rifles in that caliber had something like a 1 turn in 38" rifle twist and would not stabilize bullets heavier than 240 grain, or so I understand.
Maybe some of the newer guns have faster twist to take advantage of the newer heavier .429 bullets.
The ultimate plinking round for .44 magnum and other guns using a .429 bullet is a .433 muzzleloading round ball, weight about 122 grains.
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