John Peterson from United States, TX Public Profile

Since writing my previous review, I have purchased the HK MR556 A4, and installed this trigger along with the Haus Tool 'SELECTOR AXLE HK MR95 HAUS'. All features of the A4 remain operational with the exception that I cannot SAFE the gun unless hammer is cocked. Short throw feature of the safety lever is retained.
I am more enthusiastic about the trigger now that I have additional experience with it. It is a true two stage trigger, but there is no 'click' as might be expected. The first stage requires a 3.5 lb. pull, then a wall is reached. The second stage requires only a 1 lb pull. The release characteristics are excellent. Of course it is possible to simply pull through both stages completely to release the hammer.
I used a 1/16" pin punch to drive out the pin from one safety lever. Once the axle was removed from the receiver, I used a piece of soft pine board with a 3/16" hole drilled to receive the driven out pin of the other safety lever. The pin punch had to be pounded straight several times during this process. Along with the 'SELECTOR AXLE', I also purchased the 'Maritime Pins' for reinstalling the safety levers. I used a larger punch when driving these pins until flush with the edge of the safety lever, then evened them up with the 1/16" punch. BTW, removing the original trigger, and installing the new is easier while the safety axle is out of the receiver.
It might be possible to remove the HK Selector Axle and modify it using a Dremel tool. The $50.00 I spent f

I'm always looking for the best deal possible; Optics Planet had the best price for this trigger, Defense Depot had the best price by far for the MR556.
The rifle comes with a good trigger, the Geissele is better. The spring design of the Geissele trigger/disconnector portion is more robust and will likely never fail or become compromised by sand or gunk. Release of the Geissele hammer is crisp and more predictable, with only a trace of creep. Keep it properly lubed and it will remain your favorite trigger for this rifle.
Removal of the H&K trigger is a little tricky. The hammer comes out in the usual manner. The trigger/disconnector must be shifted forward to clear the safety, then pushed up and out. There is a silver "clip" which holds this assembly in place by friction even after the pin is removed.