Took the old girl to the range today. Loaded up some 220SMK that at my house(100 yd range) shoots lights out big holes. Today though as I'm making an attempt to walk her out to a grand, she starts throwing tantrums after 500yds. I loaded up 76gn of H1000 under some 220 SMK. CCI LRM and winchester brass. She hovers around 2876 give or a take a few. I use both Strelok and a Kestrel for a calculator, I do so for redundancy but mostly because I'm super familiar with Strelok but I'm trying to learn the Kestrel. Anyhow, this morning she was spot on dead nuts out to five hundred, from my table the 600 wasn't that visible so I jumped to 700 and I rang her at first but she started creeping to the right a bit. At 900 I was maybe 4 for 10 from the bench and at a grand I was just as reliable. All shots were taking from a bench, targets were either 8" plates or an IPSC. I was super disappointed because close in this is such an amazing load. Granted I don't have a hundred rds through this rifle yet but geez, what a kick in the ego.if I dialed it back to 500 it was spot on again but last that she was iffy. I tried the data on both devices, realized I made a BC mistake but corrected and never recovered. I just think she should have done better. Any opinions?