By bolt, I meant the bolt carrier group (sorry for the confusion). Detailed breakdown here:
http://www.olyarms.com/index.php?Itemid=42&id=29&option=com_content&task=view
ah, gotcha. There still may be a difference between AKM bolts, though. Not sure if there is, though. So you got me looking at my bolts and carriers.
I pulled the carriers from a few AKMs that I had on had (PSL, Romanian G, AMD-65, Bulgy AK74) and examined them. All of these rifles were military rifles at one time in their life, and all had a rate reducer in them. Even the PSL even though it only was semi-auto (it lacked the auto sear in it's military form). The PSL had the rade reducer as a safety precaution to prevent slam fires, so it had a carrier that had the features needed to operate a rate reducer (reset it, anyways). I know the rate reducer and whatever it was to operate it was removed by the importer (in my case, Century Arms).
You can see the PSL carrier at the bottom of this picture. The other carriers are above it.
Here you can see a machined section of the carrier. This is the region of the carrier that would reset the auto rate reducer when the bolt carrier flies back after a shot when it resets the hammer.
and here, clearly, you can see extra machining work that isn't congruent with the other machine work used to form the carrier back when it was born.
So yes, you can have a semi-auto carrier in an AKM. However, it could still fire automatically (theoretically) if you had the 3rd pin, auto sear, and a "semi-auto" carrier.... your rate reducer just wouldn't work. And you'd quickly find that your illegal AK would fire out of control (probably).