I think Matt's in the same place that a lot of course match shooters found themselves in back in the old days....they used what they had on hand.
There were few really short actions but many shot the matches with a 308. I can still see a bunch of match rifles built on 30/06 length pre 64 actions.
An old pal, Bernie F,was an engineer,accomplished match shooter and did some articles for Precision Shooting. His two Palma guns were 308's on pre war 30/06 actions. Between them he told me he had close to 200,000 rounds through the pair of them.
