In a factory rifle I would take a look at a 458 [Win or Lott, in reality for your first Big Bore the Win Mag will do just fine] in a Whitworth, CZ, Ruger 77, or a Ruger No1.
We have also had excellent service from 2 Weatherby Dangerous Game Rifles in 458. Ours have the synthetic stock.
No problems of any kind in a couple of hundred rounds [each]. The Ruger No1's are fun rifles to hunt with and add an extra element to the hunt.
For serious North American hunting of Big Bears, Moose, and Elk the 400 and 450gr premium bullets are the way to go. For everything else the 350 Hornady RN at 2000 to 2350 fps will work just fine.
The bought in bulk [and thus cheap] Remington 405gr bullets at 1600 to 1800 fps make good plinkers and are ok for deer and pigs.
For your first Big Bore, especially if you are going to be shooting it a lot a 458 is hard to beat IMHO.

Scott,
okay, i'll bite a little. This list is in no means complete. and this is only answered because you asked.

1: lathe, at least a 9x20, depending on the spindle through hole (at least 1") with a tailstock
2: reamer holder (floating preferred) that fits your tailstock
3: action vise and wrench
4: reamer
5: depth micrometer
6: go gage (i like no-go as well.. at $28 bucks each, it's hard to pass)
7: feeler gages
8: a GOOD set of calipers
9: any of a number of sources on headspacing a rifle barrel.

there's probably 10 things I am missing, but this is a basic list

jeffe

I hate to point out the obvious, but by the time you buy all this equipment, your "cheap rifle" is NOT going to be cheap at all.

Has anyone thought about the Mossberg SSI one? It is availible with a 12ga rifled slug barrel. Just looking at bolt thrust, it is chambered in 270 so the area ratio shows that it should hold a 12ga at 20ksi. I don't know if the barrel would hold it or not. I suppose you could look at the thickness of the chamber and barrel, then see if they make them out of 4140 or what. Then do the thin wall pressure vessel equation to see what it could handle as far as pressure goes. You could either use some converted 50 BMG cases or get some 12ga brass and load the terminator slug. You could get one in 30-06 and an extra 12ga slug barrel so you could have something practicle and something to blow up watermelons with. MSR = $505. Just a thought, then it would be truly Big bore. 12 bore express? I'm not saying to take it Buff hunting, but it would be fun to play with. I read an Australian hunting mag a few years back that covered a Rigby 10bore double. They shot a Cape Buff with it and it fell over and died, no fuss no muss. The steel clad bullet was found just under the hide on the off side.

As far as tools go, I think that you could cut down on the list considerably.
Get the Midway Adams&Bennet 458win short chambered barrel. Then get a barrel vise and action wrench. Pull the old Mauser barrel off, then screw the new 458 barrel on. Have the bolt face opened up or use a dremel if your careful. You can use an empty case for a head space gauge or use an actual guage. Clymer sells a Tee handle for reamers, they also sell an extension that will let you come in from the back of the action and use the Tee handle and finish reamer to set the headspace. Remember to use lots of cutting oil and clean it out inbetween checks. Go slow and check often. Rigid Dark Thread Cutting oil is very good. If you want sights, then Brownells sells NECG sights. Either take to a gunsmith to put on the barrel or try it yourself if your feeling dangerous. Get a barrel band sling swivel while your at it. Brownells also carries cross bolts for the stock. You could also have the gun smith drill and tap the reciever for a scope base or do it your self. Get the one piece base. Clamp it in place, then drill the first hole and tap it, then put a screw in. Go to the back and do another one, put the screw in. Then do the other two. You don't need to grind off the charger hump as the new one piece bases will clear it. Brownells has the drills and taps for this. Get several taps as they can break. You might have to grind the rear screws shorter to get the bolt to operate freely.

Mauser rifle $100-300
A&B 458 barrel $100
Reamer $100 or rent $30?
Tee handle and extension $40?
Barrel vise ? made my own
Action wrench $55?
Sights $60?
Scope base and rings $60
Scope $250-350?
Gun smith drill and tap reciever $10-15
Gun smith install sights?
Stock?
cutting fluid
Acra glass
Timney trigger $40
Low swing safety $15
Turn down bolt handle $30 if it needs it?
Gun smith to adjust feed rails $?

Or buy a CZ $550? Might be cheaper to buy a new CZ

All $$$$ heavy on the 'ish'

jeffeosso,

I can understand your feeling, but believe me I am not trolling NOW! Also, I TRULY APPRECIATE your comments so far.

I have some manufacturing engineering experience, but those machines were highly specialized and not conducsive to machining anything except hinge pin components for large material handling equipment.

Robert stated that I would need an action wrench and a barrel vise, I had figured that out myself. I guy from the local range told me if I stay with the belted case an empty case will "work just fine for a head spacing gage" but I am thinking an actual head spacing gage is better. I guess my biggest question is, do I really need a lathe for the barrel fitting? To get the bolt opened up I was just going to have local tool and die shop do it, they do considerable work for a previous employer and I figure I could get it done cheap. However, they won't fit a barrel to an action, due to "work place safety" reasons.

Thanks for enlightening me as to how to cut tapers on a lathe, although I won't be able to put it into practice.

Robert, I answered your questions on the "My Gun Collection" thread.

ASS_CLOWN