Hello Frank,
If you reload the simplest solution may be purchase of a mould. The largest supplier of moulds for the 500 S&W is probably
Mountain Molds. The web site features a bullet design program that's simple to use- you can order blocks that produce bullets exactly matching your needs. The proprietor of this young firm has overcome the product quality problems he had initially; over the past two years the moulds produced have consistently been very good.
Given a well thought out bullet design a 700 (to as much as 725) grain bullet will easily and correctly chamber in a S&W 500 Magnum revolver.
If you have one of the (discontinued) Taurus revolvers in 500 S&W magnum I can't state positively that a cartridge loaded with a 700 grain bullet will chamber. At least some Taurus revolvers were made with a cylinder shorter than that used by Smith & Wesson; I do not know if any of the shorter cylinder Taurus revolvers were released for sale or whether what I saw was a prototype or salesman's sample. A short cylinder such as I saw on one Taurus would limit available powder space so much that were a 700 grain bullet used with any powder that I'm aware of magnum level velocities at safe chamber pressures could not be produced: I'd be surprised if you could obtain much over 300 m/s.
Due to the substantially shorter length of the cylinders used in John Linebaugh's 500 and 500 Long these very heavy for caliber bullets, despite the slightly larger diameter, again cannot practically be used even though the case length of the 500 Long is nearly as long as that of the 500 S&W.
Used in standard S&W revolvers ballistic stability of the 700 grain and heavier bullets is adequate for short range and, depending on bullet design and other factors, perhaps medium range shooting. The rifling twist of standard 500 Magnum S&W revolvers is 1:18¾" (one turn in ~ 476 mm). This is the reason that the barrels of John Ross/ S&W Performance Center revolvers were made with a rifling twist of 1:10" (one turn in ~254mm).
If you intend to use this ammunition in a rifle I'd suggest a bullet with a very long bore riding section and a blunt or round nose. Carefully measure the land (minor) diameter of your barrel and have a mould made so that there's not more than 0.02 mm clearance on the bore riding section of the bullet. Also, give careful consideration to how the bullet will interact with the throat (leade) of your rifle.
One final comment: if you're a hunter you might note that with the 500 S&W Magnum it's possible to obtain the greatest enery with more than adequate penetration with bullets of about 500 grains. Velocities of over 1700 f/s (520 m/s) with a (muzzle) energy of over 3400 ft/lbs (~4600 joules) at under maximum permissable pressure are possible.
Bob
