What's this piece that fell out of my M&P 15-22?

[SomeGuyWithAQuestion]

I changed the pistol grip on my S&W M&P 15-22 (to a Magpul MOE-K) and when finished, surprise: a piece of plastic on the floor:





I couldn't see an obvious place in the gun where it had come from. It's about 0.63"/1.6cm long and plastic. Does anyone know where it's supposed to go?


The rear takedown pin isn't capitve anymore either since the change, I'm not sure if that's related to the mystery piece or the grip (or my lack of skills).

 

[cjt50]

Its the safety detent.

The grip on the 15-22 has 2 springs and detents when removed, the safety and takedown pin. Where it's bigger 5.56 brother only has 1, the safety.

If you need to replace lost parts, the 15-22 uses standard take down detents and springs.

 

[SomeGuyWithAQuestion]

Ah, thank you! "Detent" led me to another topic on this forum and a video on YouTube. I'll take the grip off and try again tomorrow.

 

[strobro32]

Be very careful replacing the grip bolt. The plastic receiver threads are easily stripped.

There are many threads here about it.

 

[SomeGuyWithAQuestion]

I see, I guess they already got stripped a bit. When replacing the screw it went in fully but never came to the point where it stopped turning/was screwed in. I dropped in a dab of super glue around the screw to make sure it doesn't get loose. (So hopefully I won't get bored of this grip ).


Thanks for your advice, all parts are back where they belong and she's working fine.

 

[dsf]

It's a safety detent for sure. Have scoured the floors from time to time when swapping out grips. But. a safety detent made of plastic? How long does that last?

 

[80sgyrene]

If the rear takedown pin is no longer captive, I would think the pin came from that assembly.
Does the safety still feel normal?

 

[Eric300]

If the rear takedown pin is no longer captive, I would think the pin came from that assembly.
Does the safety still feel normal?

It has already been determined and acknowledged that it is the selector switch detent that fell out while swapping out the pistol grip.

 

[tenntucker]

I was always under the impression that if you took something apart, put it back together and only had one leftover part, you were good to go.