Up until the end of 1968, if you sent your Magnum model back to Ruger, they would fit a 22 LR cylinder for a token fee. A 22 LR will fit snug in a 22 LR cylinder and loose in a Mag cylinder so it is NOT safe to shoot 22 LRs in a Mag cylinder because it will rupture the case.ĭuring the same time period as when your gun was made, 22 LR only and 22 Convertibles just had '.22 CAL' roll marked on the left side of the frame. if it chambers a 22 Mag cartridge, it is a Magnum cylinder. You might want to make sure your cylinder is for 22 LRs because it was shipped with only a Magnum cylinder. Ruger started making convertibles in 1961 with 22 LR and 22 Mag cylinders so there was a period where both the Magnum models and Convertibles were in the same serial number sequence. Duplicate serial numbers always have an interest with OM collectors. the 'D' was hand stamped and the serial number was machine stamped and are usually obvious. in other words, Ruger screwed up and used the same s/n on two guns so the second one got a 'D' stamped in front of the S/N. first because it was sold as a OM Magnum model (no 22 LR cylinder) and secondly because the 'D' in your S/N means it was a 'duplicate' serial number. Fuzzybonz, You have a nice Single-Six there.
