I'm working up a load for a 300 win mag and had some big velocity jumps through the chrony. First string was 2852, 2840 then 3085. Next string with a grain up went 2962, 2925 then 3065. Stopped there. Had 3 different loads up to there and nothing unusual. I'm loading a 200 grn berger with fed 215 primer and retumbo powder. Is my chrony on the fritz? Haven't experienced this before. Thanks for any imput.