Im planing on converting my 308 saiga to 260 Remington. it will have a heavy long fast twist barrel. my goal is a praire dog at 1000 yards and getting there with the 223 is tough. the grndal is a good round but it dont hold a candel to the 260 REM for long range work. it would be great out to around 400 yards however. with a AR mag well addapter a 223 could be converted to 6.5 grendal with just a barrel swap and possably some bullet guide work.
there are some other 6.5 wild cats that would be good as well 6.5x250
6.5x300 savage. would be a good conversion for a AK If loaded correctly. the 6.5 credmore is another.