Interesting issue with my Battle Arms BAD-CASS short throw

[Interrupt]

Installed on Colt 6920 lower with a Magpul K grip. Normally it has a good, positive click on and off, but I just noticed when I took it out of the case that it wouldn't fully go back on safe. It stopped about halfway between what should have been the 50* SAFE and FIRE arc. Nothing look like it was binding. Screws were tight.

I removed the safety and the grip and simply reinstalled everything, which corrected the issue. I still can't figure out what caused it. Anyone seen anything similar? I'm using the Battle Arms-supplied detent and spring. The gun hasn't been fired, and I didn't see anything amiss when I looked inside the lower.

[Duffy]

Was your hammer cocked? I'm sure you're aware, but had to ask anyway :jester:

Of course, the safety can't be rotated to SAFE with the hammer in the up position with vast majority of triggers, there exists a bit of slack, less than 5 degree of movement, far less than 25 degree (1/2 of 50 degree total arc) you described.

[Interrupt]

Thanks for the response, Duffy!

Unfortunately, the selector moves in this 25 degree range while the hammer is in the up position. For comparison, my stock Colt safety moves only about the 5 degrees you mentioned with the hammer up.

[Duffy]

Interrupt, what kind of trigger do you have? Since it's not happening now, I'm not sure if you can replicate the problem. If it happens again, check the detent's pointy end is pointing up, and the selector is installed with the detent groove on the right (ejection port) side. Also, take a look at the detent, and look for grooves on both sides of the pointy end which would indicated premature wear.

These seem and indeed are basic, I've seen otherwise fairly knowledgeable AR folks make these mistakes. I used to handle support for Battle Arms when I was a partner there, I wouldn't say I've seen everything but it was damn close. This may fall into one I haven't seen, if it was working as designed all this time, and the AR wasn't taken apart and put back together where a little safety installation mistake found its way to the AR. Usually these little goof ups would manifest themselves in function checks immediately.

Did you happen to disassemble the lower, and reinstall everything before you put it in the case prior to over rotation?

[Interrupt]

It's a stock Colt trigger. I just noticed that with the hammer up, pulling the trigger will actually cause the safety to rotate quite a bit if it's not completely in the FIRE position.

I'll re-check the things you mentioned and post back. Thanks so much for all your help.

[Duffy]

The trigger's "tail" can cam and rotate the selector on a short throw one. Perhaps it would go away if the throw is increased to 55 to 60 degree. The AR trigger was designed for 90 degree throws, though short throw selectors work well, they work with a design that was meant to interface with a 90 degree safety and can have little things like this that will never happen with a 90 degree selector.

With a 90 degree arrangement, the selector's flat is above the trigger's tail, the rise of the tail (as you squeeze the trigger) hits the flat at 5 degree or less,with most of the tail hitting and stopping at the flat, and has nowhere else to go. On a short throw, the tail hits the flat at an angle, and can cam and rotate it given enough pressure.