Of the three late Ilion era Parker 12-gauge, 3" guns I've recorded, two are on the 1 1/2 frame and one is on a 2 frame.

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One example is an early PH (or NH) grade ten gauge Twist Steel gun in my collection that letters as a 3 1/2" gun.


That has always perplexed me as the longest 10-gauge cases our ammunition manufacturers cataloged were 3 1/4-inch.