frozen selector switch on an AR

[ghbucky]

A few weeks ago I put my AR into the safe cocked with the selector on SAFE.

I took it out yesterday to clean it, and after putting it back together, the selector was frozen. It simply would not budge out of Safe.

I finally had to release the pistol grip and drop the detent completely out.

When I put it all back together it was fine.

Any ideas what would cause that?

 

[4V50 Gary]

Detent hole too deep? Drilled wrong?

 

[HWS]

I have had trouble with selector switches. But my trouble resulted from non-mil spec selector switches. For $10.00 you can get a new one at Del-Ton just to make sure.

 

[RKG]

Be sure the disconnector spring isn't inserted upside down.

 

[ghbucky]

Be sure the disconnector spring isn't inserted upside down.

Wait, what? There is an up/down to them? How do I know which way is correct?

 

[krunchnik]

Spring looks the same on both ends-what are we missing??

 

[Unclenick]

The wider end is down in the trigger and the narrower end is in the disconnector notch. There's a photo you can see here when you scroll about 3/4 of the way down.

 

[krunchnik]

OP is talking about the pin that fits into the notch in the SAFETY SELECTOR-not the disconnect on the trigger group.

 

[ghbucky]

OP is talking about the pin that fits into the notch in the SAFETY SELECTOR-not the disconnect on the trigger group.

Yes, correct.

The detent had locked the select lever. For reasons I cannot fathom, it would not move, yet it freely dropped out when I released the pistol grip.

And after I put it back together, with the same detent and spring, it has functioned fine.

I've ordered replacement detent and spring, but that's a hail mary, I'm clueless what caused it. I guess a bit of grit inside the tunnel could lock it up.

 

[stagpanther]

Was the rotation of the selector stiff and gritty before? Sometimes the location of the holes as well as the width of the selector can make a difference. The trigger rockers in the well and the rear shelf of the trigger rides against the round part of the selector and is "released" to firing on the flat on the selector. I've run into a couple of times trigger designs that if the pins drifted a bit changing the contact angle between the trigger and selector or a piece of debris--like a chunk of blown primer gets caught up in that area--it can create a wedge effect preventing easy rotation of the selector.

Stealing the picture from the link above--this is the contact area between the trigger and selector.

 

[ghbucky]

I would expect that if it was debris in that contact area, there would have been 'wiggle' in the selector. When I removed the detent, the selector went completely free, no resistance at all.

I'm pretty convinced that something was preventing the detent from compressing and locked the selector in place.

 

[stagpanther]

I would expect that if it was debris in that contact area, there would have been 'wiggle' in the selector. When I removed the detent, the selector went completely free, no resistance at all.

Receiver cross pins can do the same thing, often it is because of an ever-so-slight offset in the holes between the upper and lowers; it doesn't take much. Anyway sounds like you got it fixed.

 

[Maxwell Haus]

Detent in backwards, after taking it out it was put back in correctly is my guess.

 

[ghbucky]

Receiver cross pins can do the same thing

I did replace the trigger a while back, so those pins were removed and re-installed. Is there a way to confirm that they are properly aligned?

 

[stagpanther]

Depending upon the trigger design, there are generally notches in the trigger and hammer pins designed to go through in a particular orientation so that the legs of the hammer spring can sit in them. Not all trigger groups use them though. If the pin drifts enough (hence the popularity of after-market anti-rotation/drift pin sets) the orientation of the trigger or hammer can be altered.

 

[4V50 Gary]

Field expedient repai - take a file and round off the top of the detent.

Note: with the right parts, you shouldn't have to do any of this. It should work the first time. Non-spec parts?

 

[ghbucky]

It is a milspec lower from Anderson.

I replaced the mil-spec trigger with a drop in, and used the same pins.

I've checked the selector several times since that happened and it has worked perfectly every time.

 

[Scorch]

Detent in backwards, after taking it out it was put back in correctly is my guess.

Safety detents only go in one way.

 

[Maxwell Haus]

Safety detents only go in one way.

Correct, if you know which end goes in first .

 

[Scorch]

Correct, if you know which end goes in first .

If you try to put it in the other way, the safety falls out.