Today I took delivery on an early Stevens 44, four digit s/n, which has in it what is seems to be a Single Set Trigger arrangement. It worked once for me, but now doesn't smack the sear hard enough to disengage it. I've got it apart. Very dirty inside. Cleaned it up, but getting it back together is a puzzle I haven't solved yet.  Very few parts - the trigger itself, a sear, and two springs.  Still trying to figure it out. 

Anybody else know anything?  I've read vague references, but this is the first I've ever seen, or even seen depicted.

Phil 

One more part.  There is a screw through the trigger part which adjusts the sensitivity of the let-off when set.

The more I look at this thing the more I realize that it's not actually a low s/n 44 at all.  It has the central extractor and the two-piece "bolt" pivots.  Did they take a lower tang assembly from the 44-1/2, complete with serial number, to build what must be a custom rifle, sometime after 1903.?  Was there a SST option for the 44-1/2?  More research.

Well, that further suggests that this 44 rifle is a post 1903 custom, using a 44-1/2 tang.  The tang assemblies used in 44-1/2s are 99% congruent with the ones used in 44 and even the 1xx series.   

Darnedest thing is, it's got a 30 inch octagon .22 barrel on it, and with the set trigger you'd think it would have a tang sight of some sort. but nooo, it's got the plainest of irons on it, fixed rear.  Barrel s/n matches.  Two-screw forearm.  

Got this one back together.  It had a sear spring in it that would do for a truck suspension.  Sear spring from a DST would do, but I'd have to machine the tang where it screws down.  Instead I narrowed the truck spring to about 30% of what it was, and that did it.  It's now a pretty sweet set-trigger, with many fewer parts than the DST. 

Dry firing it, I now see one disadvantage.  It's more difficult to set with the rifle on your shoulder and aimed.  That would not have made it popular with the Schuetzen men.   

FWIW  I have archived pictures of a couple of 44-based models with the 2-screw forearm, but they are high grades, 50 and above. Not many were built, and undoubtedly fewer survive.   
 
BTW the face of this receiver is marked 44 and 0/0.  The 0/0 is thought to be a marking used for custom builds. 

This investigation opens a hypothesis explaining two other 44s in my data that have the central extractor and bolts, yet have a s/n that comes long before the either were introduced.  Both  have DST,  suggesting that they too were built after 1903, and their serial numbers actually come from the 44-1/2 sequence.

Phil