Any cartridge that you purchase below a 30-06 is only going to be duplicating the performance of what you already have but in a slightly different package.

So, assuming that you aren't really looking for some performance advantage from the cartridge itself but rather just want a light weight rifle. I would look at the Remington model seven, Winchester model 70 feather weightor ultimate shadow, Tikka T3, Browning X-bolt, etc...