I bought the slide fire conversion kit for the M&P15-22.

It came with a 3.5 Lb CMC trigger and Slide Fire E-Clip trigger pins that say designed specifically for the M&P15-22 right on the package.

These pins aren't long enough. They don't make it all the way through the lower receiver so obviously I can't put the clips on.

Is there anyway I'm making a stupid mistake? Or what trigger pins should I order?

I don't know about using a slide-fire, but I put an ALG-ACT trigger in my 15-22 and one of the experts on this site suggested I use "Colt 901" trigger and hammer pins (available from Geissele), and he was absolutely correct! They are flush with the receiver, where the stock pins were too short.

Actually they are slightly proud to the receiver, but it is not noticeable. You might try them and they might work.

Rick

You could also try the 15-22 specific KNS pins. I have them in mine and they are a great addition that work fine with my Hiperfire 24C trigger.

Others have them with CMC and I'm led to believe they work equally as well with those.

Hope that helps.

Rob

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Utrinque Paratus

I just installed these on my 15-22
CMC Anti-Walk Pin Kit-For Smith & Wesson M&P 15-22 22LR

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Shield9-LCP Custom-M&P 15-22

I just installed those too. I have the slide fire with the cmc 3.5lb trigger and it fits perfectly.

.154 will work, if the lower is older and worn go to .155
Get the extended pins, if you don't , when tightening them they will squeeze the sides of the lower and bind the trigger

I'd call whomever you purchased the Slide Fire kit from.

They obviously included standard AR anti rotate pins instead of the MP 15-22 versions.

Get what you paid for.

Or get the KNS Anti Rotate Anti Walk pins for the 15-22.

That way, no receiver pinch and no pins moving or falling out.

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Utrinque Paratus