I helped a friend put his back in use that was sitting in the cabinet for probably 20 years. Scoped it, and made up some moderate handloads. His is also a micro grooved probably late 70's or early 80's. Tried the Barnes 200 grain XPB bullets and it hated those. Foamed the barrel and let it soak overnight, then switched to 240 XTP's and it could almost be called a tackdriver. 44.0 H4198 is the charge. Not a top book load, but plenty. I don't think the long all copper bullets do well in that slow twist and they probably weren't catching the microgrooves really well either.
