What would be next in this progression?

[RicMic]

I do reload.  Most of what I shoot are my reloads.  I was indeed thinking in terms of power on target for the next higher powered round.  But since the 280AI has been sold the step would be from the 25-06, making the 300WM look like a pretty good bet.  That being said, I would still need at least one more, maybe a 375 round, Ruger or H&H, to complete a NA battery.  Or I suppose that I could just go to the 338WM and call it good.  Decisions decisions...

[mcwoodduck]

I can not say enough good things about my .338 WM.  Mine recoils like a 30-06.
Depending on what game your going after.  The 338 has more energy at longer ranges than does the 375.  I also own a 375 H&H as well.  But the rifles are set up for different types of hunting.
If your after Elk then there is nothing better, it works well for brown bear, moose, and does well on smaller game like deer and hogs.
If you looking for something that will fit on your reloader and stay with the 7X57 mauser base (30-06, 8 mauser, 308..... )then the 35 Whelen would be a good choice and work just as well as the 338 WM for large game at 250 and under ranges for that matter 338-06 or 338 Federal would work just as well.  Bullets have a better sectional density in 338 over 35's.
Either of the Mags will require a Mag powder measure if you reload on a dillion.
If your not planning on reloading.
the 338 WM has a larger selection of loadings and premium bullets are about 1/2 the price of .375 H&H ammo.
Right now I can get either 225 grain 338's or 270 grain 375's by Remington for around $40 a box  ( Cabela's or Bass Pro).  When you go to other loads the .338's head from 50 to 85 a box and the 375's range from 75 to 125 a box depending on bullet weight and design.

[drdougrx]

If I were in your situation (and your 280 was gone) , I'd think 06 or 308 and 338wm as a heavy.

[longwinters]

I can't believe you got rid of your 280AI.  I love my 280 but think one in AI (or a 7m08AI) would be lots of fun.

Long

[RicMic]

I can't believe you got rid of your 280AI.  I love my 280 but think one in AI (or a 7m08AI) would be lots of fun.

You know, I really like 7mm bullets but, I was looking for a bit more of a step up in power over the 25-06.  And then the rest of my Encore barrels are blue/bull and this one was standard/stainless, it just didn't match the rest of the set.

[mcwoodduck]

If you really like the 7mm then a 7mm Rem Mag with the 160 grain bullets would be a natural for any large game hunting and the 140's for any big game.  You can even go lower for predators and Varmints.
What kind of hunting do you want to do with this?  After all it's not a one gun to do all.  Besides this is the Medium bore Forum so we are all thinking 32 cal to 38 cal.
Another option could be the 9.3's the rimed 9.3X 74 or the 9.3X62 are smack in between 338 Mag and 375.

[RicMic]

I was thinking bigger than whitetail.  Elk, hogs, black bear, moose and African plains game.  No big five or grizzlies.

[mcwoodduck]

Depending on where you hunt hogs a 7mm Mag with a scope would be perfect for all of those critters.
If you read the Hog hunting sites, I'm the only one who has hogs at 100 to 200+ yard shots.  Maybe it's where I hunt.  One of your other rifles would work out well.  What kills deer kills hogs.  Again depending on where you hunt them you may want open sights or a low power scope.  Heck the 30-30 kills elk.  The standard magnums just give you the ability to shoot farther with less bullet drop making it easier to place shots at 200 + yards.
A few years ago someone asked if I knew anyone who would want to buy a 7MM Mag.  I knew my friend would want it so I started to look at ballistic tables, read Boddington on Rifles, and read what ever I could about the 7MM to argue him out of it and for a 338 or 8MM Rem.  I was amazed.  I always thought why get a 7mm with 175 grain bullets when a 30 cal with 180 was better.  The more I read, I really liked the 160 grain bullets.  Sectional density was fantastic, bullet selection was abundant, and with the velocity at 3000 fps the bullet drop was minimal.  Recoil was light and there is a large selection of rifles made for it.  Optics is where your rifle will be a mountain rifle or a woods rifle. 
The same time my friend went out to the range with me, two other guys at the range had just bought 7mm too.  One was the Sig and the other was a Browning A bolt with the noise maker on the end.  That BOSS system really works at reducing recoil.  I tried his hand loads and it was like shooting a 223.  I thought he had loaded it way down to equal 6.5X55 Swede.   I then grabbed one of the 150 grain rounds from my friend and tried it in the A bolt.  Same result.  The other two were not bad as far as recoil goes.  On Par with 30-06 but nothing like the 375H&H.  I am not really recoil sensitive and I do not shoot the 375 off the bench unless I have to.  The Sig 970 is a neat design as well.  It allows you to change caliber by removing the barrel to stay in the same family and you can change bolt faces and mags to go to other shell families.  The down side to the design is the scope mounts to the action and you would need to keep the same scope for all calibers and remember where you dialed it to move back and forth.
McDuck.

[poncaguy]

I have a 26" 338 Federal TC Pro Hunter..............a very accurate and mild recoiling round in my Encore. All the power I'll ever use. My next choice is my 35 Whelen Handi rifle.

[NONYA]

I load my 7MAG with 160gr Barnes TSX's and 60 gr of 4350 powder,this load will kill anything you plan on hunting as fast as any of the calibers you are considering and the ballistics(DROP) are better than most.