Barrel flat - frame size stamps
 

In order to determine if a barrel will fit a particular frame size, is that a series of measurements taken and/or a stamping on the flats that corresponds to what frame size it will mate with?

Thank you.

The rear most barrel lug should be stamped with the frame size

To determine the action frame size you need to measure the distance between the center of the firing pin holes

Sorry. Yes. I got it backwards, and should have written water table instead.

I've been searching for a barrel for a 1 1/2, and have found a couple of barrels but there are no lug markings to denote the size they'd mate with. Did Parker always mark the lugs with the frame size the barrel would fit?

Well. I have one that is not marked

You seem to have seen a couple

So I'd say. No not always

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.

Barrels will be marked with the frame size on the bottom of the bolting lug. With the exception of very early hammer guns and barrels that may have had their stamping filed off for some reason.
Determining frame size of the frame itself would require measuring certain areas of the frame. Firstly the firing pin spacing. And for some frame sizes, the height of the standing breech is also an important area to look at.

What would be measured on a barrel with no frame size stamp present, and what would those measurements need to be for it to interface correctly with a 1 1/2 frame?
Thank you.

TPS page 527? has a chart with all the measurements.

What bill said. The serialization book also has this info as well.

Thanks. I have neither book. I guess I'll look around for copies to buy.