You asked about caliber in a lightweight all-around rifle and my two votes are .270 Win or 7x57r. It really depends - if you are planning international hunting I’d stick with the 270 for more common ammo availability. For domestic hunting, either works.
I went the Merkel K1 / K3 route for myself / my wife - they are our Africa rifles. My K1 is in 7mm Rem Mag with a VX3 2.5-8...and the K3 is 7x57r with a VX6 1-6x. Both are 6#, 5oz scoped and are an incredible joy to carry. That 7 Mag is definitely sharp on the recoil, driving a 150gr. E-Tip at 3,000 fps in a 24” barrel...while the K3 drives that same 150 E-Tip at 2,550 fps with it’s 20” barrel.
And they are both lookers. That K3 in the safe is without a doubt the best looking rifle in the safe!
So that’s my vote.
