The .500 S&W Magnum is a semi-rimmed, straight cartridge optimized for use in revolvers.
The cartridge is designed to headspace on its rim.
However, unlike rimmed cartridges such as the .44 Magnum and other cartridges designed for use in revolvers, the cartridge can be cycled more smoothly and more reliably in tubular magazines, due to the semi-rimmed design.
However, the cartridge does not cycle well through box magazines.
The rim tends to lock in the extractor groove.

The .500 S&W Magnum was designed to fire a bullet with a diameter (⌀) of 0.500 in (12.7 mm) unlike the .500 Linebaugh, which fires a 0.510 in (12.9 mm) bullet.
This was done so as not to run afoul of the National Firearms Act and be considered a Destructive Device as had happened to Whildin’s .50 AE cartridge, which at first was designed to fire a 0.510 in (12.9 mm) but had to be redesigned to fire a 0.500 in (12.7 mm) instead.

SAAMI compliant .500 S&W Magnum cartridge schematic: All dimensions in inches [millimeters].

The .500 S&W Magnum has a maximum working pressure of 60,000 psi (4,100 bar).
 However, most factory ammunition is limited to 50,000 psi (3,400 bar) to help ease extraction of fired cases.
 The cylinders of the S&W Model 500 revolver are engineered to be capable of withstanding 50% over pressure.
 Regular proof-load testing is performed at 20% over pressure.

The cylinder bore diameter is given as .500 in (12.7 mm).
SAAMI recommends a 6 groove barrel with each groove being 0.130 in (3.3 mm) wide.
A barrel with a bore diameter of 0.4880 in (12.40 mm) and a groove diameter of 0.4983 in (12.66 mm) is also recommended.
The recommended twist rate is 1 in 18.75 in (476 mm).
While the bore diameter of 0.4880 in (12.40 mm) is consistent with other firearms which fire a 0.500 in (12.7 mm) diameter bullet, the groove diameter of 0.4983 in (12.66 mm) is an oddity as most firearms which fire a 0.500 in (12.7 mm) will have a groove diameter of equal to the diameter of the bullet.

While the overall length is given as 2.300 in (58.4 mm) by many sources, some revolvers will not be able to accept cartridges with bullets seated to this overall length.
 This is because the cylinders of the revolvers are too short to accommodate such cartridges.
 The now-discontinued Taurus Raging Bull 500 is an example of one such revolver.
 It has a cylinder which is about 0.200 in (5.1 mm) shorter than that of the S&W Model 500.
The .500 S&W Magnum is a semi-rimmed, straight cartridge optimized for use in revolvers. The cartridge is designed to headspace on its rim. However, unlike rimmed cartridges such as the .44 Magnum and other cartridges designed for use in revolvers, the cartridge can be cycled more smoothly and more reliably in tubular magazines, due to the semi-rimmed design. However, the cartridge does not cycle well through box magazines. The rim tends to lock in the extractor groove.
The .500 S&W Magnum was designed to fire a bullet with a diameter (⌀) of 0.500 in (12.7 mm) unlike the .500 Linebaugh, which fires a 0.510 in (12.9 mm) bullet. This was done so as not to run afoul of the National Firearms Act and be considered a Destructive Device as had happened to Whildin’s .50 AE cartridge, which at first was designed to fire a 0.510 in (12.9 mm) but had to be redesigned to fire a 0.500 in (12.7 mm) instead.
SAAMI compliant .500 S&W Magnum cartridge schematic: All dimensions in inches [millimeters].
The .500 S&W Magnum has a maximum working pressure of 60,000 psi (4,100 bar).  However, most factory ammunition is limited to 50,000 psi (3,400 bar) to help ease extraction of fired cases.  The cylinders of the S&W Model 500 revolver are engineered to be capable of withstanding 50% over pressure.  Regular proof-load testing is performed at 20% over pressure.
The cylinder bore diameter is given as .500 in (12.7 mm). SAAMI recommends a 6 groove barrel with each groove being 0.130 in (3.3 mm) wide. A barrel with a bore diameter of 0.4880 in (12.40 mm) and a groove diameter of 0.4983 in (12.66 mm) is also recommended. The recommended twist rate is 1 in 18.75 in (476 mm). While the bore diameter of 0.4880 in (12.40 mm) is consistent with other firearms which fire a 0.500 in (12.7 mm) diameter bullet, the groove diameter of 0.4983 in (12.66 mm) is an oddity as most firearms which fire a 0.500 in (12.7 mm) will have a groove diameter of equal to the diameter of the bullet.
While the overall length is given as 2.300 in (58.4 mm) by many sources, some revolvers will not be able to accept cartridges with bullets seated to this overall length.  This is because the cylinders of the revolvers are too short to accommodate such cartridges.  The now-discontinued Taurus Raging Bull 500 is an example of one such revolver.  It has a cylinder which is about 0.200 in (5.1 mm) shorter than that of the S&W Model 500.
.500 S&W Magnum