Tim, I'm going to respond to your question in a more complete manner as soon as I can take some photos and get them posted here. Meanwhile I'll say that yes, the SSTs seem to have more problems than the others, and IMO it's due primarily to their wider availability to some of the less-informed shooters over the years. The SSTs are far more common than the other set-trigger styles and, since they closely resemble the standard setup, it appears to me that many folks thought the little screw adjustment was for the actual trigger pull and not for the set mechanism. Consequently it appears that many of these SST rifles simply had their set mechanisms misadjusted or ignored, while the presumably more informed CCDST and Schuetzen DST shooters were able to keep theirs working properly for the most part.
Another factor that may be a contributor is the relative ease of converting a standard trigger to the SST system. Many of these conversions have been done over the years by parts swappers and home craftsmen, some of them without a full understanding of the specific adjustments required for proper operation.
The design of the wall's hammer is such that the two sear surfaces of the full-cock and safety notches lie at different distances from the main sear's fulcrum; this requires the kicker's position and travel to be adjusted so that the main sear is (just barely) free to engage both notches, and this sometimes is difficult. What usually happens is that the kicker holds the sear either too far forward (doesn't fire when tripped) or too far backward (won't fall into the notch unless the trigger is set). The kicker design allows the sear to have a limited travel arc, and the limits of this arc must be adjusted so that it allows full sear engagement in both sear notches without any special manipulation of either hammer or trigger.
This sometimes proves difficult, but I'll walk you through it in my next post with the aid of photos. At least I'll try...
This would have been a series of articles if The Powers on the dark side hadn't begun losing my article submissions. The SST and the CCDST are especially worthy of further exposition and the home-craftsman conversion to SST would also be a worthy subject.
It may take me a day or 2 depending upon honey-dos and other responsibilities but I'll take some photos and post a further description. Also, I usually have a limited parts supply on hand if needed, and Ballard LLC has them for ransom. However it seems from your description that your problem will be easy to fix without any expense. We'll see.
Regards, Joe
