nfmMike,
It looks like MikeG has you pretty well squared away on the details on the cartridges I mentioned. The 7mm STE is indeed a .307 Winchester necked down with a sharper shoulder angle and case taper reduced in order to maximize case capacity. It is the rimmed version of the 7mm SGLC (Simpson's Good Little Cartridge) which is based on the 7mm-08 casing. I feel your pain in relation to the 8Mag. Every once in awhile I'll screw the muzzle brake off my .340 just to remind myself I'm not made of steel.
It's a shame that the 8Mag went away, as it was a good cartridge. The lack of bullets that would stand up to the velocity afforded by this cartridge, and the fact that it needed a magnum length action are most likely what did it in. Not to mention the fact that it was bracketed by several very capable 308 and 338 caliber magnums. I used to want one of these in the worst way and "settled" for a .340 Weatherby. The .340 is a .338 by the way, same bullets, different name. You can get all the power of the 8Mag, and then some, with the new crops of magnums. Having shot a lot of rifles, I think most people, myself included, are probably better served with cartridges based on the 30-06 casing than the magnums. There are too many of these to list, but the 338-06 would be an excellent choice for heavier game. The 280 (.284 or 7mm) Remington, one of my favorites, is everything the .270 (.277) is and a little more versatile. If you want a laser beam, the 7mm STW is it. Just make sure to keep the barrel cool or it won't last too long.
