Not yet sure about caliber, 7mm-08, 338-06, 25-06, or stick with an 8mm chambering and just get a new barrel.
Honay, something struck me when I read Mikey's comment about staying with the 8mm, which of course I advocate if you need a good heavy hitting cartridge.
You mentioned 3 cartridges up there that you'd possibly change to.
The cals are fairly divergent, I might say.
338-06 is a real thumper, 25-06 is varmint right out to a good sized deer and 7mm-08 is multi-purpose so I'm actually a little unsure as to where you're heading by building in one of these.....what do you actually need? :|
Plus 2 are standard action and the 7mm-08 of course is short action.
Why waste the extra action length on a short action cartridge?
What ever the case here are a couple of cartridges that may suit.
7x57 is perfect for the 98 action and requires no alteration at all to feed perfectly.
It also has no upper limit in terms of bullet weight(
unlike the 7mm-08) and is pretty forgiving in terms of recoil.
If you're reloading you couldn't find a better all round cartridge as it'll perform as well if not better than a 7-08 with premium handloads or with the Hornady Light Magnum load.
280 Remington is also excellent if you like 30-06 based cartridges.
It's not far behind the 7mm Rem Mag in terms of performance and has a very wide variety of bullets due to it being a 7mm round.
If you're really up for an interesting rifle try chambering in 7x57 Ackley Improved or 280 Ackley Improved.
Brass is easily fireformed from standard rounds and the leap in performance is quite considerable for both cartridges.
Best of luck. :wink: