List of triggers that work with HK416, MR556A1 or MR223

This question comes back every so often. I decided to try collecting list of trigger groups that work with HK firing pin safety, so can be used either in lower other than HK or dropped into HK lower. Looks like most M16/M4 select fire triggers work with it, so list is of semi-auto triggers. Please take in mind that HK firing pin safety takes some hammer energy to disengage. Using very light trigger setup with light hammer springs can lead to light primer strikers on some brands of ammo (surplus, Russian, etc.):

ALG Defense ACT
Armalite National Match 2-stage
ATC AR-Gold Trigger (needs fitting for MR223 due to rear receiver pin location)
CMMG Gen2 2-stage
Franklin Armory Binary Firing System III (BFS III)
JP Competition Trigger
JP EZ Trigger
Geisselle HK MR556
KAC 2-stage
RRA National Match 2-stage (CAUTION: Only new version with rounded hammer is compatible)
TAC-CON 3MR 
Timney AR-15 Skeletonized
UHL Trigger (German made)
Wilson Combat TTU-3G and TTU-M2

I will try to update this list when new info will come in. Please give confirmed info on other triggers, I will update list.

WARNING: Some triggers will not work properly with HK safety from 2-stage "European" trigger (one that allows to be put on safe with hammer down). Old style HK safety or aftermarket safety may be necessary.

Remarks:

Geisselle SSF - standard model reported not to work reliably with HK416, special model required.

Last update 27th of Dec 2017 (BSF III added)

3Gun Liga Sportera - Podstolice 18.03.2012

Unlucky match for me. Managed to twist my right knee on stage 1 (second stage I shot) while putting pistol to the box. Fortunately nothing serious - my knee pads helped to keep my knee ligaments together. I finished stage fueled by adrenaline and with support of elastic band and some strong painkillers finished match.
This match was also first opportunity to test Mesa Tactical Urbino stock on my Benelli Supernova. All I can tell, this stock is amazing! Finally I have some sort of control over that thing.

You may want to check LewPrzem's YouTube channel (Click Here!). This guy really knows how to shoot, for now, he is unbeatable around here. He shoots in Tactical class, but even in Open class we do not even come close. Maybe because he trains for our taxes ;)

3Gun Liga Sportera local match at ZKS club

Club level 3Gun Liga Sportera. I decided to take it easy and brought my Mini-Beryl rifle. It is second time ever I use it in competition. Fun shooting it. On stage 2 with evil clays best tactics to win, was dump 5 rounds as fast as possible at them, abandon rifle run with pistol and accept 5 misses (25s penalty). But I was taking it easy and decide to shoot for fun. On stage 3 my RDS decided to go off for some time (it is cheap Delta Optical RDS), but later on it returned. Battery contact I think. Stage 4 is just mu usual lack of skill with shotgun. For so small range with only 2 50m bays available for dynamic shotting and restricted rifle use (can not take rifle forward of firing line per range regulations, it was fun shooting anyway.