Was very sorry to hear of Coopers passing. I enjoyed Cooper, but my faves that I can read over and over are Skeeter and Bill Jordan.
I like Pearce too. Not really new, but I imagine you've read Taffins books on Big Bores. Pretty good read. And for nuts and bolts Gil Hebberds "Pistol Shooters Treasury" is hard to beat. Just got Ropers Experiments of a handgunner, havent got deep into it yet though.