.284W done in a LA
A .30/06 with a 22" barrel would be a fine and versatile light rifle for Africa, that would still be at home in the sheep mountains. Even Jack admitted that it was more versatile than the .270.
Still, for a classic "O'Connor" style sheep rifle, it should probably be a .270. You have to consider, when it's all said and done, if you choose some other calibre whether you'd find yourself wishing it was a .270 instead.
I only want an American caliber as I am building my gun in the classic American style. So 7x57, etc isnt on my radar.
Anyways, I really appreciate all of the interesting thoughts here so far.
I've spent a lot of time thinking about these same ideas. I planned on doing a Model 70 as well for light packing and general North American game. While 7x57 fits the bill, and is perfectly period correct for a vintage Model 70, my choice was going to be 280AI. If you wanted, normal 280 is also perfectly fine. The reasoning for choosing that over a 270 was the wider variety of 7mm bullets than that of the 270 Win. The cartridges are for all intents and purposes, basically identical otherwise. If you have a long action, you might as well take advantage of it with a longer case than a 7x57. I will say though, if you never plan on handloading, it is a bit of a moot point.
I am also of the mindset that for what you're planning on doing, a big magnum really is quite pointless. A good bullet and load from a 270 or 280 is more than flat enough shooting for ethical distances, without the blast, recoil, and hard to find ammunition of the 300 Weatherby you're suggesting.
As an aside, if I were to do a Model 70 in a magnum cartridge, it could only be a 300 H&H. While you would need to find a H&H magnum length action, there really isn't anything else like it for smooth feeding, cool factor, and nostalgia.
270 Win or 280 (or280AI) are my vote.
I agree the H&H is a great old magnum but I am really wanting to stick with a very "American classic" cartridge.
This rifle will essentially replace the old .308 FWT I bought as my first rifle. So I am thinking should I go .270 classic.... My one buddy said I should build it .270 and as light as possible while maintain handling of course and then just look for a nice German made vintage .300 Weatherby.
Built my sheep hunting rifle years back. Because I spent a lot more time climbing and hiking than shooting, I went with a lightweight rifle. Took a Rem 600, lengthened the mag box to allow 3.1" col, and put slim taper 23" barrel on it. Aluminum mounts and rings, and a small Leupold scope. Put it in a wildcat stock as soon as I could. Light, easy to carry, accurate. Not as pretty as it could be, but I found sheep country rough on rifles. - dan
It sounds to me like you really want a .270, so you should just go for it. Featherweight contour 22" barrel.
In 284 WIN like mine Dan ? RJ