Service six dao conversion to DA/SA

[stonebuster]

I've interchanged Six Series hammers with no issues in the past. I bought a DAO NYCPD Service Six 38 recently and decided to swap hammers with my DA/SA Speed Six. It worked. I bought another spurred hammer for the Speed Six but the hammer didn't lock up when a pulled back for SA. I thought the "new" hammer was faulty or had been tinkered with so I bought another from a different seller. It didn't lock up for single action either in the Service or Speed Six but did in a Security Six I own. After searching online I found a forum thread posted by someone who had gone through Ruger armorers training. He posted a diagram from his manual detailing hand fitting a da/sa hammer if it didn't lock into to sear. Basically it required careful light filing to remove just enough metal off the hammer to allow the hammer to move backward enough to engage the sear and lock for SA. Too much filing would result in hammer push off was cautioned. This all leads me to believe hand fitting is sometimes needed due to slight differences/tolerances between revolvers. Now that I have an extra hammer & the manual info and diagram I may try a couple light strokes with a file to allow a bit more backward hammer travel. Anyone else here had to do hand fitting on a Ruger hammer?