There had been reports of the 45 degree selector’s compatibility with couple of triggers, so I will elaborate this issue a little. This is something potential 45 degree selector customers should keep in mind.
So far, we know of two triggers that seem to have issues with the 45 degree selector: AR Gold, and Wilson Combat’s TR TTU (the original TTU works fine). To this, I have to add that these triggers have heretofore caused issues with the 45 degree selector, but they may not be ALL incompatible. The AR Gold trigger I have, for instance, works on my 45 degree receiver and selector just fine.
The first generation of TTU used to have set screws on the bottom to allow some height adjustment, subsequent models have springs, the only way to “adjust” them is by clipping off coils. Without these springs, the trigger will fire even when the selector is on SAFE. With them installed, they push the entire housing, and the trigger’s rear tail up and puts it in contact with the selector center.
This isn’t a problem with 90 degree selectors, as the rotation is a full 90 degrees, the travel is too long for the trigger to complete a rotation to FIRE. With a short throw selector, the tail touches the leading edge of the flat area of the selector and can rotate it out of detent engagement.
Partially this has to do with the angle the detent hole are cut, we’ve since changed over to a different angle that allows much less movement when the detent is engaged. When the lever is on SAFE and perfectly parallel to the bore, the trigger cannot rotate the selector out of detent engagement. When there’s a light movement in the selector, the trigger has a better chance of rotating it out of detent engagement.
Also at fault is the taller trigger “tail”. When a manufacturer improves a trigger, by definition it is already not in original specs. Our selectors are designed for in spec receivers and triggers, as long as both are close enough to the original specs, the tolerance stacking issue is mostly a moot point.
Our favorite triggers are the Geissele triggers, all versions of Geissele are compatible with the 45 degree selectors, as well as factory, RRA, JP, KAC, etc.
Since being on the market in late 2010, we’ve had but two or three reports of incompatibility, so this is definitely not a wide spread symptom.
