I definitely know that the current RRA trigger is different than the Armalite/LMT trigger.
I have both a RRA & an Armalite.
The design of the RRA is better in terms of the disconnector. The RRA has more allowable disconnector travel, while the Armalite, showed the opposite. The Armalite does not have enough disconnector travel.
On the Armalite, there isn't enough room for the disconnect to move rearwards. The disconnector bottoms out on the trigger before the disconnector can pivot around and catch the hammer. If the disconnect bottoms out on the trigger and the hammer still needs to come rearwards, then it is going to push the trigger out towards your finger. Not a good design IMO. This of course would occur when you fire a round and still have the trigger held rearward. You would not detect this if you forgot to function test it with the trigger back.
The RRA on the other hand has about twice the avaialble room for the disconnector to move rearwards. This allows for proper function.
The Geissele is also different from the other 3 and appears that it would have enough disconnector travel for proper function.
If you look at pics of these models you will see the noticable difference in disconnector setups between the RRA, Geissel, & LMT/Armalite.
Would you folks with Armalite and LMT triggers care to function test with your trigger back and report your results?
Function test - unloadered firearm, manually cycle the action, dryfire the weapon and keep the trigger held back. With the tigger still held back, grab the charging handle and manually cycle the action again. Did the tigger push back on your finger?