458 SOCOM ballistics fall into two groups: light and mid-weight supersonic bullets loaded short enough for an AR15, and heavy subsonic bullets that trade velocity for weight. Chattahoochee Munitions manufactures a 650 gr Maker REX 458 SOCOM subsonic load that averages about 1,010 fps from a 12.5-inch barrel, with about 1,473 ft-lb at the muzzle and about 1,342 ft-lb at 100 yards. This 458 SOCOM ballistics guide collects the velocity, energy, and drop figures for that load and puts them beside typical AR15-length 458 SOCOM loads.
458 SOCOM Ballistics Chart: Common Bullet Weights
Typical published factory velocities for AR15-length 458 SOCOM loads are shown below with the muzzle energy each produces. Energy is calculated from bullet weight and velocity, so actual figures vary with barrel length and the specific load.
| Bullet weight | Typical muzzle velocity | Muzzle energy | Speed class |
|---|---|---|---|
| 250 gr | About 2,150 fps | About 2,566 ft-lb | Supersonic |
| 300 gr | About 1,900 fps | About 2,405 ft-lb | Supersonic |
| 405 gr | About 1,600 fps | About 2,302 ft-lb | Supersonic |
| 600 gr | About 1,000 fps | About 1,332 ft-lb | Subsonic |
| 650 gr Maker REX (Chattahoochee Munitions, 458 SOCOM XL, CM7S bolt action) | About 1,010 fps (12.5-inch barrel, measured) | About 1,473 ft-lb | Subsonic |
| 650 gr Maker REX (Chattahoochee Munitions, 458 SOCOM XL, CM10 semi-auto) | About 1,012 fps (12.5-inch barrel, measured) | About 1,478 ft-lb | Subsonic |
The 650 gr load carries about 10 percent more muzzle energy than a 600 gr subsonic at nearly the same speed, because below the speed of sound weight is the only way to add energy. For cartridge comparisons, see 458 SOCOM vs 45-70 and 458 SOCOM vs 450 Bushmaster.
458 SOCOM Ballistics for the 650 gr Subsonic Load
Chattahoochee Munitions measured a 10-shot average of 1,010 fps from a 12.5-inch CM7S bolt action barrel and calculated the trajectory below with a 100-yard zero. The CM10 semi-auto load averages about 1,012 fps from a 12.5-inch barrel (about 1,478 ft-lb), so its trajectory is nearly identical.
| Range | Velocity | Energy | Drop | Time of flight |
|---|---|---|---|---|
| Muzzle | 1,010 fps | 1,473 ft-lb | – | 0.00 s |
| 100 yd | 964 fps | 1,342 ft-lb | 0.0 in | 0.30 s |
| 200 yd | 925 fps | 1,235 ft-lb | -35.9 in | 0.62 s |
| 300 yd | 891 fps | 1,146 ft-lb | -112.2 in | 0.95 s |
- Bullet: 650 gr Maker REX, solid copper expanding, lead free, .458 inch, 2.035 inches long
- Ballistic coefficient: .44 G1
- Sectional density: .443
- Overall length: 2.802 inches (CM7S bolt action), 2.790 inches (CM10 semi-auto)
- Brass: Factory-new Starline 458 SOCOM
How Heavy Bullets Change 458 SOCOM Ballistics
A heavy, long bullet has a high sectional density, so it loses velocity slowly. The 650 gr REX gives up only about 46 fps over the first 100 yards and still carries about 1,146 ft-lb at 300 yards, roughly 78 percent of its muzzle energy. The tradeoff is drop: at about 1,000 fps, the bullet spends almost a full second in flight to 300 yards, so it falls about 112 inches below a 100-yard zero.
For practical shooting, these 458 SOCOM ballistics mean known distances. Inside about 150 yards the trajectory is easy to manage with a 100-yard zero and a ranged hold. Beyond that, range the target and dial or hold carefully. Read 458 SOCOM effective range for holds in MOA and mils.
Why a 650 gr Bullet Needs 458 SOCOM XL
458 SOCOM was designed to fit the AR15, which limits the cartridge to 2.260 inches overall. The 650 gr REX is 2.035 inches long, so at AR15 length it would sit about 1.35 inches deep in a 1.575-inch case and leave little room for powder. Chattahoochee Munitions loads it as 458 SOCOM XL, 2.802 inches overall for the CM7S and 2.790 inches for the CM10, which seats the projectile less deeply and reclaims case capacity. The chamber and case are standard 458 SOCOM; the firearm and magazine have to be configured for XL length.
Barrel Length and 458 SOCOM Ballistics
Subsonic loads reach their velocity early in the barrel, so a short barrel gives up little. The Chattahoochee Munitions figures above were measured from a 12.5-inch barrel, the length its 458 SOCOM subsonic load is tested in. At about 1,010 fps it stays subsonic even at 0°F, where sound travels about 1,051 fps. Read 458 SOCOM subsonic for more on staying below the speed of sound, and 458 SOCOM barrel length for 12.5 vs 16 inches.
Twist Rate, Stability and 458 SOCOM Ballistics
A long, slow bullet needs a faster twist to stay stable than a short, fast one. Common AR15 458 SOCOM barrels use a 1:14 twist for lighter bullets. Maker recommends 1:10 or faster for the 650 gr REX, and Chattahoochee Munitions 458 SOCOM barrels use 1:10. See 458 SOCOM twist rate.
Bolt Action and Semi-Auto Loads
Chattahoochee Munitions loads the same 650 gr projectile two ways. The bolt action load is 2.802 inches overall for the CM7S. The semi-auto load is 2.790 inches overall with a propellant configuration that cycles the CM10. The two are not interchangeable; the differences are covered in 458 SOCOM bolt action vs semi-auto.
Firearms for 650 gr 458 SOCOM
Chattahoochee Munitions manufactures complete factory firearms chambered in 458 SOCOM and configured for 458 SOCOM XL:
- CM7S 458 SOCOM 12.5-inch bolt action pistol or SBR
- CM7S 458 SOCOM 12.5-inch SBR with PLACID OTB
- CM7S 458 SOCOM 16-inch bolt action rifle
- CM10 458 SOCOM 12.5-inch semi-automatic SBR
- CM10 458 SOCOM 16-inch semi-automatic rifle
See every configuration on Terminal 458.
458 SOCOM Ballistics FAQ
How fast is a 458 SOCOM?
Typical AR15-length loads run from about 1,600 fps with a 405 gr bullet to about 2,150 fps with a 250 gr bullet. Subsonic loads run about 1,000 to 1,050 fps; the Chattahoochee Munitions 650 gr load averages about 1,010 fps from a 12.5-inch CM7S and about 1,012 fps from a 12.5-inch CM10.
How much energy does 458 SOCOM have?
Typical supersonic loads produce about 2,300 to 2,600 ft-lb at the muzzle. The Chattahoochee Munitions 650 gr subsonic load produces about 1,473 ft-lb at the muzzle and about 1,342 ft-lb at 100 yards.
What is the heaviest bullet for 458 SOCOM?
Chattahoochee Munitions loads a 650 gr Maker REX. At 2.035 inches long it is loaded as 458 SOCOM XL, beyond the AR15’s 2.260-inch limit.
How much does 458 SOCOM subsonic drop at 200 yards?
The 650 gr load drops about 35.9 inches at 200 yards and about 112.2 inches at 300 yards with a 100-yard zero.
What 458 SOCOM ballistics does the 650 gr REX have?
.44 G1, with a sectional density of .443.
Who makes 650 gr 458 SOCOM ammunition?
Chattahoochee Munitions manufactures 650 gr Maker REX 458 SOCOM XL ammunition, loaded separately for the CM7S bolt action and the CM10 semi-automatic.
Does barrel length change 458 SOCOM subsonic velocity much?
Less than it changes supersonic velocity. Subsonic loads reach their velocity early in the barrel, which is why Chattahoochee Munitions tests its subsonic load in a 12.5-inch barrel.
What twist rate does 458 SOCOM need for heavy bullets?
Maker recommends 1:10 or faster for the 650 gr REX. Chattahoochee Munitions uses 1:10; common AR15 barrels use 1:14.