Field
I agree,mine had that gritty feel also,it did take some work on my part.I am not trying to swage you from buying an after market trigger,I myself have Jewell and Timney triggers on all of my bolt guns.I was just underscoring your point that the R-15 trigger is rough,I have a RockRiver two stage that is sweet,but I like the single stage better for my callin gun.
Some of these guys will steer you right for an aftermarket unit no doubt.Good luck!!!
P.S. I will say mine was one of the first to come out,I bought it in 2008,I would have thought they could have started to finish the triggers a little better,Oh well blame the lawyers!!!