There had been reports of the 45 degree selector's compatibility with couple of triggers, so I will elaborate this issue a little.

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.

The problem we identified with the AR Gold trigger was the trigger's rear extension is too tall.  The trigger's rear extension interfaces with the selector's middle, flat section.  Our middle, flat section measures 0.240, a cast selector's mid flat section is about 0.230.  The milspec is taller than both of these.  We've reduced the center diameter couple of times to make it more compatible with aftermarket triggers that deviate from Colt specs, in the case of the AR Gold trigger, it's just too much.

Below, left is my receiver with an RRA trigger, hammer uncocked.  Right is an AR Gold trigger, hammer uncocked.


The trigger's rear "tang" is super elevated, and can cause problems with either the 45 or 90 degree selector.

Many of you know we've been talking about playing with the throw distance for months.  We've made close to a dozen prototypes with various throw distances.

The reason for this is simply the inevitable slack exists when the selector is rotated to either FIRE or SAFE.  The detent holes must necessarily be slightly larger than the detent itself, or the detent can't go into the detent holes. The detent holes must necessarily be slightly larger than the detent itself, or the detent can't go into the detent holes.  This slack and angle of the detent holes are the reason for the 2 to 4 degrees of movement when the detent is engaged, with the selector rotated to either FIRE or SAFE.  Though with the latest development we did on the detent groove and detent holes, the slack has been reduced, we are always looking for ways to further improve things.

With a 45 degree selector, 4 degree of movement each way is more exaggerated than it is on a 90 degree selector.

With triggers that are spec, or close to spec, the 45 degree selector cannot be rotated from SAFE to FIRE by pressing on the trigger, the experiment with 50 to 55 degree selectors has nothing to do with this issue that's really a tolerance stacking problem caused by triggers that are too beyond spec measurements.

No decision has been made on these longer throws.  We're of the opinion that 45 degree throw is the optimum throw arc for a short throw selector.  HK, FN, and other manufacturers apparently feel the same way, for their throw arcs sometimes are even shorter.

In other news, a short throw M16 selector is also now in development

Two questions:
1) Can you elaborate a bit more on what the SYMPTOMS are of the specific issues?  It sounds like the parts will all fit together and yet the safety will not prevent a pulled trigger from firing when in SAFE position.

2) Can you comment on current production as I see this topic is about 2 years old as of this posting in mid-April 2014.  Do current production BAD safeties still have this issue with current production AR Gold and Wilsons TTU triggers?

Thanks!
Richard

The ST selectors went to 50 degree in early 2013 to address the compatibility issue with TTU triggers.

Though it can happen very rarely, even with the 50 degree short throw, SOME TTUs can still exhibit the symptoms.  In testing, where 45 degree had problems, 50 degree selectors did not.  Since its roll out, there had been one or two compatibility cases reported with the 50 degree selector and one variation or another of the TTU.

With the hammer cocked, selector on SAFE, if you pull on the trigger hard enough, you could make SOME TTUs cam the selector lever to FIRE and drop the hammer.  This happens very rarely, as mentioned earlier.

TTU is the only known family of triggers that we know of that ever displayed these symptoms.  No issues with AR Gold, 45 or 50 degree (referring to our ST selectors only, not anyone else's).

Gotcha, thanks - I was leaning towards a TTU, so it's very helpful to know what to check.  I wouldn't normally crank on a trigger on SAFE, but now I know to do so and look for any signs of movement.




Gotcha, thanks - I read the below and hadn't paid close attention to the "45 or 90" part:


It still might be useful to have a thread with trigger gotchas or BOLOs or whatever you'd like to call it - even if the issue isn't specific to your selector, it's good for me as a buyer to know the AR Gold might cause me trouble.  I at least promise not to shoot the messenger

Thanks!
Richard

The short throw selector is non-standard on the AR, there was a chance it wouldn't work with some triggers, TTUs (again, not all of them, only a few) are the ONLY ones we know of.

Being the AR was not designed to use a short throw, we imagined the list would be longer.

Our 90 degree selector has no known compatibility issues with any trigger.  The AR Gold trigger is hit and miss (good old tolerance stacking is a major factor here), but that's so with any selector, not just ours, so I don't consider it an incompatibility.

Cannot get the BAD ASS short throw selector to work with a Geissele SSA-E in a BAD556-LW billet lower.  Throws fine between settings, but won't fire with the shorty.  Works fine with a standard 90 degree safety.  Seems this should be the last combo with issues :)   Don't doubt that it's a problem I created, but not sure where to go from here.  Suggestions?

I have this exact combo. Works great.

I'm at a loss.  Will pull everything out and try again.  Not like it's difficult, but something's not right.  I've got a standard BAD non-shorty in another rifle - will try that first, then the shorty again.

Operates fine without the detent pin.  As soon as that goes in with spring in grip, won't release trigger when set to fire. Have tried 2 different detent pins.

Weird. Spring too long?

Tried multiple springs as well.  Emailed BAD, will see what they come back with.

No response from BAD - took it to a gunsmith to see what he can do.

 
Please email us again at [email protected]  It either didn't come through or we dropped the ball.  Sorry about that.  We are hit with record volume of emails/calls so we are lagging behind on response.  Going through some growing pains and expanding staff.  For more immediate assistance you can also call us and we will take care of you.


Thank you.

No worries - I'll let you know if the gunsmith has any issues.  Had some other stuff for him so not a big deal.

 
He will likely have to stone the top surface of that rear portion of the trigger bar that engages the safety selector center .001" at a time until the safety freely rotates without binding.  Geissele's trigger design is much taller there than milspec and it tapers down.  It is that downward slope that some times have compatibility issues with the safety.  The trigger is cast so the tolerance will vary a bit more than machined.  The binding is ever so slight when it does occur.  


The stacking tolerance issue with different aftermarket products will happen since we are all deviating from the TDP in order to make advancements in design.  Sometimes the changes don't play well with one another.  Many expects AR parts to be "drop-in" and in many cases they are.  However, it should be known that sometimes you have to do some fitting to ensure proper function especially when so many different manufacturers are involved making non-milspec parts.  


We have reached out to Geissele about making that top flat surface more like the milspec and is waiting for them to respond.

just picked up a new short throw last week, though my new lower doesn't have that detent slot I filed it down so I could use it,  it didn't like my sd3g. my other 3 lowers everything works like a champ/

I had to file down the short throw ledge until it worked. since this is a ongoing issue why don't you make them with the short throw shelf with less material instead of telling people to file on their trigger?

There is a reason why we made it the way we did.  If the material isn't there, it could become unsafe with other triggers and we will create many other problems.  We did as much as we are comfortable adjusting to accommodate the Geissele.  It would be safer to file down or modify the rear trigger bar of the Geissele trigger to fit the safety than the other way around in our opinion.

after dealing with one of your techs. i'm going to go with a dift company and get rid of what I have. but thanks for the insight.