Don't think they have any more idea than we do, perhaps even less.
For a start the only air rifle event is indoors at 10m.
Secondly, the 50m .22 stuff is shot in sheltered wind ranges. Although the scoring machines can be electronic, and you can get trace kit like Scatt which enables you to train indoors, good old batch selection is done by shooting groups, statistically analysing that, and selecting other batches that likely to produce similar or better results, until the entire production line's output is exhausted.
Generally, from the England team shooter i've worked with, they dial in till their hitting 10s... that's about it.
BFTA/NSRA County Coach
CSFTA Chairman/BFTA Rep