New action needs a cartridge

[Rapier]

Years ago I ordered a Pro Hunter action, a square bridge 98 Mauser/M-70 hybrid action intended for heavy game cartridges on a pre production, pre paid basis. Well Montana Rifle Co is getting close to actually producing the actions after what has turned into many years. The magazine will be 4.043 inches long with several bolt face diameters available, including a .640

I am concerned at this point with selecting a versatile cartridge. The action/magazine will handle a 505 Gibbs or a 500 A Square with ease. I have a 458 Lott at present and really do not have a use for the PH action right this very minute. However, if called to fill the order, including the bolt face diameter, I was wondering what would be the experienced hunters thought on the subject. In the past the good folks at MRC set the feed rails and bolt face for a cartridge based on the order for the preproduction actions. I would just build the rifle later when the wild hare got hold of me.

At present I am leaning towards the 500 A Square (460 Wetherby necked up and blown out) simply because in the US it is a very doable deal for bullets, cases and dies while some of the other exotic stuff is hard to put together for ammo. Plus I wanted a bolt gun to be in a rimless case without a rebated rim if at all possible. Remember, if the COL is less than 4.00 it should work in the PH action.

I hope I stated this clearly enough to make sense. I am trying to cover a base I might not have thought of.
Ed

[Larryjk]

If you aren't set on the truly big bore, I would recommend the 404 Jeffrey. I just have a thing for that cartridge. They are the equivalent of the 416 Rigby and are now loaded by Hornady to the same velocity of the 416. The bullet is a .423 and available from Hornady and Woodleigh. It is 400 grains in either solid or expanding. It is tapered so it looks like it wants to be improved but it should feed from the box magazine like a greased pig. They were much more popular in Africa than the Rigby until Robert Ruark wrote up the Rigby like it was magic.

[Rapier]

Larry,
Thanks for the idea. That is more like I was thinking, something that could truly be used for more than preparing the beach for an assault. I have a 458 Lott that is bad enough for most stuff walking around, unless Jurassic Park becomes a shooting preserve. The 500 A Square was just in the thought process as a bolt face selection because of the 460 brass. When you get to the big stuff you have a whole bunch of stuff to think of and the cost of and avalibility of brass is one of those things.
Best,
Ed