The Colt M4 Heavy Barrel features a true 5.56x45mm NATO Chamber for use with both commercial and military surplus ammunition, while the 1 in 7″ Twist Rifling is capable of stabilizing light to medium weight projectiles of up to about 77 grains.
| Vendor | Price | Sale Price | Status |
|---|
| Cartridge | 5.56x45mm NATO |
| Color | Black Parkerized |
| Material | Chrome Moly Steel |
| Extra Features | Front Sight Base |
| Length | 14.5 Inches |
| Twist | 1:7 |
| Threads | 1/2″-28 |
| Barrel Contour | SOCOM |
| Chrome Lined | Yes |
| Gas Block Diameter | 0.75 Inches |
| Gas System Length | Carbine |
| M4 Feed Ramps | Yes |
| Country of Origin | United States of America |