Pdawg,

THe 50 has been necked to just about everything you could think of, some legitimate experiements, most gag stuff.

THe 375x50 BMG was also used and perhaps one of the most useful of the hybrid group but it still eats throats and you need custom bullets to make it work well.

The 338 is much to tight a bore for this case. A 408 caliber onthe 50 BMG would be interesting and probably impressive with a 400 gr class VLD but sadly, all the 408 bullets on the market are poor performers in the accuracy and consistancy department.

My advise would be to just get a 50 BMG and go with that.

At extreme range velocity means very little, its all B.C. and the VLD 50 BMG bullets are the king of the hill.

Good Shooting!!!

Kirby Allen(50)

Yeah, the real question is what would you do with a 4500 fps 175g bullet?
There's no bullet made that will will perform well at that speed, and no animal that needs that kind of devastation, so really what you're looking at is having your 2800fps bullet end up further away, right? The 180g Berger would be cruising along about there at 1000m, for example.
If you're into 1000m target shooting, it might suit you, but starting out at 3625 will still land you at 1k above 2250 fps. True, there's less wind deflection when there's less hang-time, but it is going to be a lot easier to get a bullet to do 3600 than 4400, in terms of action, case, and even bullet construction.

I'm interested in the flip side of this: how fast can you get a 50-cal match bullet to go in a readily available action? I'm thinking the Gibbs necked and maxed-out and set up for Barnes bore riders as a single shot, and still chamber hunting bullets from the mag, in a CZ 550. That would give you about 3/5 the powder room as the BMG, and might reach 1k still going over 1750 fps with a 650g (if there was one.)