I bought a used Ruger Old Army that I'd like to check to see if its been modified or not. Could someone please give me the depth and diameter of a standard ROA cylinder bore so I can check that against mine.
I get the same diameter you have. The depth, however, you picked a very difficult spot to measure, as the bottom is far from flat, and the depth mike slips to the center (nipple face) every time. Near as I can tell the outer edge is 1.21-1.22, but from the cylinder face to the nipple face is 1.363. This is on a stainless.
A much older (30 years) blue one I have has a diameter of .454 and a depth of 1.21 to 1.25, depending on where, and the nipple face is 1.350.
Thanks for the info!
I chose that area of the bore to measure because I thought if it was modified, thats where the metal would be removed as the nipple depth would be standard.
If this is a standard that I believe it to be, then I'm not sure where Clements removes the metal from to increase capacity. Looks just about completely bored. Maybe the depth could be cleaned up to the nipple chamfer but that seems only a minor increase.
Anyways, thanks again!
If you feel with the depth gage, or a long tool, the wall of the chamber, you will see that there is a slight step about 2/3 of the way down. This is where the cylinder bore reaming stops, the rest of the way down is the pilot bore, cleanup of the casting. Yes, the ROA cylinder is investment cast, the only cylinder Ruger casts. That reduced diameter isn't a lot, but it probably puts more metal under the cylinder bolt notch. Clements may also, in straightening that, deepen the bore some, you could theoretically cut all the way to the nipple face location.
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