"Flyers" hmmmm. This picture is a perfect example of a good group gone bad. Using a friends 6BR I shot this four shot group at 100 yards. I shot four times because the one off to the right was the first shot. That was all me. And most times I think most flyers are due to human error most times. I continued to shoot the rifle and the remaining three shots are in a group of .307 outside diameter that you have to subtract .244 out of the equation to get a group size of .063. Man would that have been some bragging rights for me personally. But alas the "flyer".

Yours could be some more stock issues. Could be some bullet runout. Could be loading issues. Could be some human error. I'd shoot some groups at further ranges and you'll maximize your problems and this could help narrow it down. But in real time you should be able to shoot multiple groups in session without much change in impact. If that was not true then the 1000 yard bench rest shooters would be in trouble. They run 10 shots in a quicker manner to keep most of the elements the same during that one group setting.