Best drop in option in my opinion. - Partisan Triggers Disruptor AR-15 FRT 3 Position Drop In Forced Reset Rifle Trigger

Installation was a breeze and it's preformed flawlessly for me thus far.
Also when you have it installed to function test it you will need to press the reset bar forward, this trigger has a safety mechanism where until that reset bar is pushed forward it will not drop the hammer, this is by design. Its a safety feature to mitigate out of battery detonations. DO NOT PANIC IF IT DOESNT PASS FUNCTION TEST.

First things first this does come with some requirements youll need
-Fully auto bolt carrier
-H2 or h3 buffer(i use h2 and so far no issues at all)
-Low shelf lower

Provided you have those 3 things this thing will run flawlessly for you. I have tested this trigger on 6 of my uppers and so far it's run unbelievably well with the exception of one of my over gassed uppers, occasionally i get a light primer strike in longer stings of FRT fire, i suspect the excess gassing on this particular upper is to blame and an H3 buffer would fix this but since this is only an issue for a single upper i haven't bothered to buy one yet. SO KEEP IN MIND IF YOUR GUN IS OVER GASSED ALREADY YOU MAY NEED TO TUNE A BIT WITH BUFFERS but i honestly don't think you'll have much issue.

Ive run this on carbine, midnights and rifle length systems and barrel lengths ranging from 14.5 to 24 inches, low budget uppers and my expensive Super duty and LWRC upper and again not a single issue or malfunction.
ive probably got about 2k rounds on this trigger and the anti-walk pins show no signs of issue. In fact I love this trigger so much i bought a second for my dad because once he shot an FRT he really really wanted one.

As for the trigger itself in semi-auto it's nothing special at all; it has a very slight take up and then a clean break at about 6/7 ibs. basically its a Mil-spec trigger so if you're a trigger snob you may not enjoy the SA trigger pull but imo it's not an issue at all. in FRT mode the initial trigger pull has a little bit more slack but it breaks much lighter prob around 4 ibs and the reset action is nice and smooth, you dont have to worry about finding the technique or choking up the trigger, the thing JUST RUNS.

In my opinion for the price and simplicity this is the best FRT on the market currently. You dont have to worry about a compatible trigger profile or worry about supporting a company suing the pants off everyone else.

This thing lives on my Geissele super duty full time and imo the whole package makes for a pretty capable civilian IAR, i couldnt be happier about this purchase.