Just doing a ruff count on GB (they list from 1 to 10+ in each posting) there are around 300+ available. I only saw 3 in .243 and none in .308. Most in .250 then .300 and 6.5CM.
Given that it has been close to a years since marketed...are there few .243's and .308's because of low production numbers or because they sold out first and the others are the hard to sell leftovers?