This is the bullet from Buffalo Arms. I believe the narrow front section is so it can be seated at the cannelure and still chamber in barrels with narrow bores or tall rifling. Mine has a groove diameter of .364 and bore diameter of .346. Very tall lands, most likely intended for lead bullets.

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After the first shot the rest are just noise.

Make mine a Minaska

Heaven has walls and rules, H-ll has open borders