Fastbolt,

All very sage advice. And a good time to remind forum members reading this that they ought not to try this at home (Cut to Mythbusters disclaimer clip)!

As for getting specs from S&W, I would guess you're right. It's all about how you navigate the voicemail and departmental first-on-phone techs to get to the guy with the prints. I have no experience sailing those seas and figure I would die of old age before I got to someone who would be interested in helping. When I last called S&W for help on converting to DAO, I was ridiculed for having the desire and then quoted double what forum members have advertised they had the job done for.

On a similar quest to pick new sights for this gun, XS sights gave me a dimension over the phone on my first try calling their tech support. It took two weeks of phone followed by email tag to get the same number from Trijicon. After my first reply Novaks basically ignored me (but have been great on the phone other times). You just never know how it's going to go until you try. Next time I will give S&W a call but I won't hold my breath

As I just can't seem to leave well enough alone, I went ahead and put the frame back in the mill and dug out another 0.050". This allows the catch detent to be set flush with the frame surface as you kindly suggested it ought to be in your first reply. I like it and have edited my post and picture to reflect it. Be sure to go back and look at the photo (hopefully it will refresh for you) to see the overall look. Here's a close up where you can see the detent 'leaning' into the bore a little more than I like. This was due to my choice to move it inward for a more positive engagement.



From my measurements, the catch must articulate about 0.065" inward to put the outmost edge of the tooth of the catch flush with the inside of the magazine bore. When I originally had the bore drilled at 0.475" I was not able to set the button flush as 0.475-0.420(coil bind length of detent+spring)=0.055", off by 0.010". I decided to go an extra 0.040" and take it all the way to 0.525" so I could match the effort required to release a fully charged mag to a stock gun.