Re: AR-15 Triggers- a mini-study
Installation Report of Rock River Arms Two Stage trigger in AR-15
I got the trigger from Brownells and installed it today and here is what I found:
I installed it out of the box but the pins were "oversized" (by design). They were 0.1555 inches and stock pins are suppose to be 0.1540 inches. The instructions say to grease them up and force them into the receiver holes. I had trouble with that whole concept. Swaging my receiver out to those bigger holes would not ever allow me to go back to any other trigger system and those pins might not fit through anyone else's trigger parts. So I used the original Mil Spec pins. There was very little movement laterally of the RRA trigger parts on the smaller stock pins when installed in the receiver. Not using the RRA oversized pins appears to not had an adverse impact on the trigger pull.
The first stage measured 3 1/2 pounds and the step up to the second stage was another 3 pounds for a total of 6 1/2 pounds although it didn't feel much like a 6 1/2 pound trigger. I was not satisfied.
I reshaped the trigger return spring by trial and error and finally settled on a first stage pull of 2 pounds. Any less and the trigger return spring could not always over power the friction of the system and fully return the trigger forward after a partial pull. The resultant pull was 2 pounds first stage and an additional 3 pounds for the second stage for a total of 5 pounds. That seems like a lot but all you really notice is the increase once you get to the beginning of the second stage.
There seemed to be a minute bit of roughness so I very very lightly stoned the primary sear surfaces on the hammer and the trigger, adding a bit of moly grease to both sear surfaces and to the nose of the primary sear where it bumps into the secondary sear. The pull didn't change all that much but felt smoother. The let off is very crisp.
I like this trigger. My only comment is that the secondary sear spring seems a bit heavy (which effects the weight of the second stage) but it seems to be riveted onto the trigger, not allowing modification of the pull level for the secondary stage. But as a Tactical Match level trigger, which it is sold as, I think it worlds better than the adjustable JARD or the stock trigger. I would like a little less pull for the second stage but I don't think the way it is now will be detrimental to my varmint version of the AR-15.
I suggest anyone who does not understand trigger system and/or is not a gunsmith to NOT make the modifications above (it kills the warrantee) to the RRA two stage trigger system. Install it box stock and live with it but it would not be hard to live with. The trigger right out of the box is not all that bad, certainly better than stock, and a lot safer and more creep free than the adjustable JARD single stage trigger. The JARD leaves you with a compromise: safety or minimal creep with the possibility that the gun will double (believe me I know!). The pricing on this RRA Match trigger is significantly better than any other two stage trigger I could find.
Hope this helps.
Last edited by LDBennett; 11-14-2009 at 11:02 AM..