Barrel flat - frame size stamps

[OH Osthaus]

Well. I have one that is not marked

You seem to have seen a couple

So I'd say. No not always

[Bill Murphy]

Put fired shells in the chambers and measure to the center of the primers. This is the "non machinist's" method of measuring firing pin distance by just using the barrels. 1 1/2 and 2 frame firing pin separations are the same, but other measurements are different. Refer to The Parker Story, page 527, if I remember correctly.