I decided to go ahead and post about this one, because it was a fun conversion, two, because I did it quite a bit differently than others have and three, to address the rumors which circulate about how "easy" or "quick" full auto conversions of semi auto firearms are. I was originally going to use a Remington 597 to abuse my suppressor prototypes, but I had been given this 10/22 many years ago by a friend after he discovered it had sustained severe water damage while it was in the case. The barrel was deeply pitted, many other steel parts were badly rusted, and even the aluminum had pitting. This was probably 15 years ago, and I had done kind of a billy joe bob bullpup conversion on it and painted it with hammered finish Rustoleum, then pretty much just forgot about it. Fast forward to this month, it dawned on me that it was an ideal candidate because I had no money in it and because I had a take off SS barrel with faux suppressor that was left with me after a barrel swap. So I tore it out of the makeshift bullpup stock and discarded the original barrel, shortened the SS barrel to 12", and scored a free take-off stock from my friend who runs a retail gun shop. Now came the fun.......and the frustration. First of all, there isn't a lot of room inside a 10/22 fire control housing. Ultimately, I wound up ditching the bolt hold open to make room for the auto sear. The second aspect of the 10/22 that makes full auto conversions a bit different is the disconnector arrangement; it's not a separate lever which disconnects the sear, but an integral part of the trigger assembly. If you try to take it out, the firearm won't work at all. Anyway, first order of business was figuring out how to make the disconnector stop disconnecting. This involved modifications to both the hammer and the disconnector lever, as just bobbing the tangs on the hammer isn't enough, because the hammer spring will still depress the disconnector lever. Once I got that squared away, it was time to go about figuring an auto sear. Not terribly complicated if one is somewhat familiar with full auto or select fire weapons, but the specific geometry takes some figuring. The hammer also gets a secondary cut for the auto sear. Next was the bolt, which not only needs to be cut to trip the auto sear, but also needs anti-bounce weighs and, I found to make it run reliably with a wider variety of ammo, a cut that causes the bolt to hang on the hammer just a little when coming forward. This cut also serves as a bolt hold open, since that was removed. I found that tungsten weights were necessary to stop bolt bounce, but that made the bolt too heavy for all but the hottest .22 LR HV ammo, so I milled away more material to get it back down to 6.5 oz. After some tweaking of auto sear timing and anti bounce weight travel, I had it running full auto reliably, but I wanted it to have a semi-auto function, so I tore it apart again and designed my selector. I ended up milling it from 4140 chromoly and heat treating The little pivoting finger at the bottom makes use of the angled gap between hammer spring and disconnector. When rearward, it clears both. At the forward position, though, it causes the hammer spring to depress the disconnector, giving semi-auto function. My design does not take the auto sear out of the loop; it catches ahead of the main sear, then drops the hammer to the main sear when the bolt closes. The selector pivots on an integral pin, which sits in a hole on the receiver. It is retained in position by a simple music wire spring with two V-shaped bends in it.