Now this is getting interesting! hivel37 the 7mm IHMSA is based on the .300 Savage as is I believe the 6mm version. So is the .250 Savage, with a few alterations and more case taper. And of course the .250 is the parent of the .22-250 Rem. If we're going to move away from smaller bores, why not consider a cartridge that has just be legitimized, the 6.5 x 284 Norma, if you can call that legitimate. 6.5's have very high BC's and the .284 Winchester case almost gives it magnum potential if it is ever needed for that. The round is extremely accurate and a pet of the rifle ballistician with Western Powder Co./Ramshot and new owner of Accurate Powders.
One such project I have been considering is the CZ-550 in 6.5 x 55mm, reamed to 6.5 x 284. It is not a short action, but will allow you to seat bullets to a longer OAL, just like the situation with the Swede, either could be fit in a short action if shorter OAL is maintained with lighter bullet weights. This could have serious 1000 yard potential and in fact, has already proven it does. BTW, CZ uses a slower twist in 6.5, that might make a barrel change unnecessary.
