The common 22 ARC twist rate is 1:7, fast enough to stabilize the long 75 to 88 gr bullets the cartridge was designed around. Hornady’s published 22 ARC velocities come from a 24-inch, 1:7 twist test barrel. Chattahoochee Munitions manufactures every CM15 22 ARC AR15 barrel with a 1:7 twist at 16, 18 and 20 inches, and the CM7S 22 ARC bolt action with a 1:8 twist Mos-Tek barrel at 12.5 and 18 inches.
What 22 ARC Twist Rate Means
Twist rate is the distance the rifling takes to turn the bullet one full revolution. A 1:7 barrel spins the bullet once every 7 inches; a 1:8 barrel once every 8 inches. The smaller the number, the faster the spin. Long bullets need more spin to fly point first, and the 22 ARC exists to fire long bullets from an AR15 magazine, so twist rate matters more here than in a light-bullet .22 centerfire such as the 223 with 55 gr bullets. SAAMI standardized the cartridge in 2024 with a 75 gr introduction load (SAAMI announcement).
22 ARC Twist Rate by Chattahoochee Munitions Firearm
| Firearm | Barrel length | Twist | Gas system |
|---|---|---|---|
| CM15 22 ARC AR15 | 16 inch | 1:7 | Rifle-length |
| CM15 22 ARC AR15 | 18 inch | 1:7 | Rifle-length |
| CM15 22 ARC AR15 | 20 inch | 1:7 | Rifle +1 |
| CM15 22 ARC upper | 16 inch | 1:7 | Rifle-length |
| CM7S 22 ARC pistol or SBR, barreled action | 12.5 inch | 1:8 | Not applicable |
| CM7S 22 ARC bolt action rifle, barreled action | 18 inch | 1:8 | Not applicable |
Every barrel is 416R stainless with E100 Blackout Cerakote and 1/2×28 muzzle threads. CM7S barrels are made by Mos-Tek with 5R rifling; CM15 barrels are straight-fluted.
Spin Rate: Why Velocity Matters Too
Spin in revolutions per minute equals muzzle velocity in feet per second, times 720, divided by the twist in inches. Twist is fixed, but velocity changes with barrel length, so a short barrel spins the same bullet more slowly.
| Muzzle velocity | 1:7 twist | 1:8 twist |
|---|---|---|
| 2,820 fps (published 24-inch figure, 88 gr) | About 290,100 rpm | About 253,800 rpm |
| 2,580 fps (example 16-inch, 88 gr) | About 265,400 rpm | About 232,200 rpm |
| 2,475 fps (example 12.5-inch, 88 gr) | About 254,600 rpm | About 222,800 rpm |
The 16 and 12.5-inch velocities are examples based on an assumed loss of 30 fps per inch, not chronograph data.
Which 22 ARC Bullets Suit 1:7 and 1:8
Stability depends on bullet length more than weight, and the long 75 to 88 gr bullets are the ones that need spin. Both Chattahoochee Munitions twist rates handle them:
- 1:7 (CM15): stabilizes every common 22 ARC bullet, from the 62 gr ELD-VT to the 88 gr ELD Match, from every CM15 barrel length.
- 1:8 (CM7S): stabilizes the same range, including the 88 gr ELD Match, from both the 12.5 and 18-inch CM7S barrels. Chattahoochee Munitions runs 88 gr bullets in its 1:8 CM7S 22 ARC.
For very long monolithic or custom bullets outside the factory range, check the bullet maker’s twist recommendation.
Signs a 22 ARC Twist Rate Is Too Slow
- Oblong or sideways holes in paper, called keyholing
- Groups that open up well beyond what the rifle shoots with other bullets
- Poor or inconsistent expansion, because the bullet does not arrive nose first
A faster twist does not harm accuracy with lighter bullets for typical hunting and target shooting. A slow twist with a long bullet is the combination to avoid.
22 ARC Twist Rate and Subsonic Ammunition
22 ARC is a supersonic cartridge. Its .224-inch bullets are too light to carry useful energy below the speed of sound, so twist rate choices for 22 ARC are made around supersonic varmint, hunting and match bullets. For short-barrel subsonic shooting, Chattahoochee Munitions offers heavier cartridges such as the 375 Raptor and 8.6 Blackout; see the Raptor Paddock.
22 ARC Firearms by Twist
- CM15 22 ARC AR15, 16-inch, 1:7
- CM15 22 ARC SPR, 18-inch, 1:7
- CM15 22 ARC varmint rifle, 20-inch, 1:7
- CM15 22 ARC upper, 16-inch, 1:7
- CM7S 22 ARC short barreled rifle, 12.5-inch, 1:8
- CM7S 22 ARC precision rifle, 18-inch, 1:8
- CM7S 22 ARC barreled action, 18-inch, 1:8
See every configuration in Flight Deck 22.
Related 22 ARC Guides
22 ARC Twist Rate FAQ
What is the standard 22 ARC twist rate?
1:7 is the common 22 ARC twist rate, and Hornady’s published 22 ARC velocities come from a 1:7 test barrel.
Is 1:7 or 1:8 better for 22 ARC?
Both work. The CM15’s 1:7 and the CM7S’s 1:8 both stabilize common 22 ARC bullets from 62 to 88 gr.
Will a 1:8 twist stabilize 88 gr 22 ARC bullets?
Yes. The 1:8 CM7S 22 ARC stabilizes 88 gr ELD Match bullets from both its 12.5 and 18-inch barrels.
What twist does the CM15 22 ARC use?
1:7 at 16, 18 and 20 inches, and on the 16-inch upper.
What twist does the CM7S 22 ARC use?
1:8, on Mos-Tek 416R barrels at 12.5 and 18 inches.
Does barrel length change 22 ARC twist rate?
No. Twist is fixed per inch, but spin rate follows velocity, and barrel length changes velocity.
Who makes a 1:7 twist 22 ARC AR15?
Chattahoochee Munitions manufactures the CM15 22 ARC AR15 with 1:7 twist 416R stainless barrels in 16, 18 and 20 inches, and a 16-inch CM15 22 ARC upper.