Hello all,

I recently bought a M&P 15-22, and so far I like it. Although it is quite a bit lighter than my AR. still like the similarity it shares with the AR.

One of my areas of concern is the trigger. In my Ruger 10-22 I have a Brimstone Tier Two, which is awesome. In my AR I have an ALG ACT trigger which also is perfect for my needs. Both triggers are single stage, extremely smooth and break like glass.

My question is, since I understand the trigger in the 15-22 is mil-spec (??) if this is the case, can I drop in a ALG trigger and go down the road? I submitted this question to ALG, and they said they had no hands on knowledge if the trigger would work. They had some feedback that it did, but their concern was the 22's action is a blow-back design, and they weren't sure if the trigger would work.

Does anyone here have any knowledge if this trigger will work in the M&P 15-22?

Thanks in advance,

Rick

Should be fine. I have Geissele triggers with mil-spec+ hammer springs in my 15-22s with no problems. Get 901 Colt hammer and trigger pins (Geissele has them, Brownells has them) to go with your trigger group. They're the right length (longer than what came in your 15-22) for the 15-22s' thick walled lower.

Thank you, I'm ordering one now.

I've run the alg act trigger in my 15-22. I pair it with a jp reduced weight yellow trigger spring. Keep the stock hammer spring.

You can use the pins that come with the 15-22, if you so choose

Yes he can but the 15-22 comes with the same AR-15 length pins the ALG trigger will come with. Colt 901 pins are longer and fit flush with the outside of the lower instead of recessed like the originals.

I had posted this situation to ALG, an today I got a phone call from one of the armorer's, Hakkon who told me the stock pins and the ones furnished with the ALG trigger will both be recessed in the receiver, while the 901 pins will stick out. He suggested I use the recessed pins, since the 901 pins are hardened and I cannot file them flush.

The Geissele 901 pins I have measure .995". The OE 15-22 (and std AR-15) pins are .895" The 15-22 lower is ~.990" wide at the pin holes.

That means the 901 pins will "stick out" ~.003" on each side. The original pins sit ~.050" recessed per side.

So, "sticking out" .003" or recessed .050". I like having pins long enough to use all the available bearing surface in the lower.

The .003" the 901 pins "stick out" is definitely not noticeable. To put .003" in perspective, an average human hair is ~.004" thick.

Your gun, your call.

If were going to replace the pins, I'd buy the JP Anti-Walk pins and be done with it. They're not terribly expensive, and could prevent a nasty failure. I have them in both my 15-22 and my AR.

That is an option but they do "stick out" far more than the .003" the 901 pins will.

That aside, I don't like that they don't rotate. The hammer has a j clip that drags on a pin that can't rotate and the trigger with it's disconnector will also drag. That drag is why the pins rotate.

Remove the trigger group and assemble the hammer and trigger on their pins. Try and rotate the pins in the trigger and hammer.

You lube the pins holes in the lower when you install the trigger group. There's a reason why.

Install non-rotating pins (currently fashionable but IMHO an answer to a non-existent problem) and you add drag to the trigger pull and hammer fall. With a good trigger group you'll feel it. That's why I prefer the 901 pins that I think the 15-22 should have come with...

Just FWIW.

Here's the update. I received the ACT trigger and ordered both the JP anti walk pins and the 901 Colt pins.

The anti walk pins require a "J-spring" to be removed from the hammer. I didn't want to do that and compromise the design of the trigger assembly.

I assembled the ACT trigger with the reduced (purple) spring the trigger came with. It came with two springs for the hammer, a purple one for a 4-1/2# and the Tan one for a 6# trigger. I also used the 901 pins, and the fit is PERFECT!

The trigger has no creep and breaks clean like glass at about 4-1/2#. I am a VERY happy camper!

Highly recommend this trigger modification with the Colt 901 pins. Thank you TOMCATT51!

Rick