Include used rifles in your search. When I find a well made or interesting rifle then I take the cartridge it's chambered for.
If I found a really nice rifle chambered for the .280 Rem. I would buy it. I might pass on a .280 AI however.
Current Bid $405.00 No Reserve!
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=325105194