M*CARBO Brotherhood

Flat Trigger Install

When installing the new Mcarbo flat trigger i noticed that it comes with a small washer. Nowhere on the tutorials or anywhere i could find would tell me where this goes. Please help!!!


@Irish I also watched several videos and could find no mention of a washer. Here are my thoughts. #1: Stuck a washer in the bag by mistake- but I doubt it. #2: Kel-Tec may have changed the spacing on the plastic trigger posts creating a little slop and MCARBO discovered this and added a shim washer just in case to tighten it up. Which grip frame do you have, Glock or multi-mag? I’m surprised one of the MCARBO team members hasn’t responded to your post.


I have the glock 19.


I had the same question. Did the Pro Trigger upgrade, among other things, yesterday but couldn’t find anything about the washer on MCARBO (just this post when I GOOG’d).

MCARBO tech support (email) told me the washer goes on the trigger hinge pin on the left side of the trigger to take up any slop in the lateral movement of the trigger. They said it shouldn’t effect the proper working of the trigger action. They’ll update their next video.

I checked my trigger and there IS a tiny bit of side-to-side play. So when I go to the range to test fire, I will look for any issues. If yes, I’ll install the washer soon; otherwise I’ll wait until the next time I’m back inside the grip frame for some other reason - deep clean, possible upgrade to extended mag release, etc.


@MS_Maz Welcome to the Brotherhood.


@MS_Maz first post and already contributing, I like it :+1:


@ChrisNelson said in one of his videos that the washer was put in there because some of the shell halves have a place in them that causes the trigger and trigger bar to bind up if the screw is tightened too much. The washer makes sure there’s enough space to keep it from binding.


Hmmmm.say there how IS that trigger? I’m 9 kindsa pissed off at the bloody damned P.O.S. blasted thing I just got back from LWD! Is shoulda took Chris Nelson up a while back when he was talking about coming out with aluminum triggers.damn I’m dumb!

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The flat trigger is nice. it feels a lot better to me than the curved one, and on a subbie, replacing anything plastic with metal is an improvement IMHO. I wish Keltec - or MCarbo - would make metal shell halves. I’d jump on those in a heartbeat.

I didn’t put that washer in mine. Before I got the internals upgrade I had a screw back out, and when I tightened it down tight the trigger wouldn’t reset so I backed it off a little and all was good. Chris showed that in one of his troubleshooting videos.