I just noticed, you shoot lefty?
I don't know how long you've been experimenting w/ yours, my GPR is new to me last week. What I'm finding in my online pokings & proddings is that the 80-90 gr seems to be where most shoot best; I'm hoping to find that good grouping load prior to filing any sights.
Ultimately, I'l like to zero in the 80-100 yd range. I doubt I'd ever take a shot in the field much beyond 75 or so as the kill zone is all but indiscernable to me at that distance-through open sights I see "DEER".
That peep must prove useful?