400 Legend Guide — Cartridge Design, Ballistics & the CM15
This 400 Legend Guide explores the cartridge’s development, ammunition types, published ballistics, hunting applications, recoil, and suppressor considerations. Chattahoochee Munitions offers it in the CM15 with a 16-inch barrel, 1:16 twist, and midlength gas system, available in Black Tungsten, FDE Metallic, and Cobalt Kinetics Green.
A straight-wall case and .40-caliber projectile give the cartridge a distinctive place among modern hunting rounds. Its appeal combines substantial bullet weight with a format suited to both traditional rifles and the AR15 platform. Understanding that role requires separating cartridge specifications, ammunition performance, and the configuration of the complete rifle.
400 Legend Guide: Origins and Hunting Purpose
Winchester publicly introduced the cartridge on April 13, 2023. Its 400 Legend announcement described a straight-wall hunting round intended for deer, hogs, black bear, and other big game, with moderate recoil.
The design addressed interest in centerfire hunting rifles where straight-wall cartridges have a particular role. It also provided another option for hunters who prefer the familiar controls and magazine format of a semi-automatic rifle.
Cartridge classification and hunting permission remain separate matters. A straight-wall designation does not establish that every rifle chambered for it is permitted in every season or location. Firearm type and magazine-capacity requirements can matter independently of cartridge dimensions.
Cartridge Dimensions and Case Design
Winchester’s Power-Point product page lists a .4005-inch bullet diameter and 1.650-inch case length. The case has a straight-wall profile rather than a pronounced shoulder and reduced neck.
Winchester describes the design as having a rebated rim. That term means the rim is smaller in diameter than the main case body. Case profile and rim design describe different parts of the cartridge; a straight-wall case can also have a rebated rim.
The dimensions help identify the cartridge, but they do not establish interchangeability with another .40-caliber round. Similar bullet diameters are not equivalent to matching chamber dimensions. This 400 Legend Guide concerns factory ammunition specifically marked for the chambering.
400 Legend Guide: Factory Ammunition Options
Factory offerings illustrate several approaches to the cartridge. The table identifies examples by weight and bullet category, rather than treating all ammunition as equivalent:
| Manufacturer and load | Bullet weight | Design or role |
|---|---|---|
| Winchester Deer Season XP | 190 grains | Polymer-tipped deer-hunting bullet |
| Winchester Power-Point | 215 grains | Hunting offering |
| Federal Power-Shok | 210 grains | Jacketed soft-point hunting bullet |
| Winchester Super Suppressed | 300 grains | Subsonic target and range offering |
Polymer-Tipped Hunting Ammunition
Winchester’s 190-grain Deer Season XP uses the Extreme Point design with a large polymer tip, contoured jacket, and lead-alloy core. Winchester identifies it as ammunition developed specifically for deer hunting.
The tip is part of the bullet design, rather than a cosmetic difference. Construction helps explain intended use, while the published specifications describe the particular load. Bullet weight alone does not communicate either completely.
Conventional Soft-Point Ammunition
Federal’s 210-grain Power-Shok uses a jacketed soft point and traditional lead core. Federal lists 2,250 fps muzzle velocity and a .207 ballistic coefficient. Its 210-grain weight should not be confused with Winchester’s 215-grain offering.
Different brands can use similar product names while offering different bullets. Power-Shok and Power-Point are separate ammunition lines; use the actual manufacturer, product designation, and weight when reading specifications.
Subsonic Range Ammunition
Winchester’s 300-grain Super Suppressed is listed for target and range shooting at subsonic velocities. Its jacket encloses the bullet base to help reduce lead fouling in barrels and suppressors.
A heavier bullet does not automatically make a load a hunting selection. Likewise, a suppressor-oriented label does not establish expansion characteristics or confirm cycling in a particular semi-automatic rifle. Keep the manufacturer’s intended application attached to the load.
400 Legend Guide: Published Ballistics
The following table reproduces Federal’s published velocity and energy figures for its 210-grain Power-Shok load. These are manufacturer reference data, not measured CM15 results.
| Distance | Velocity | Energy |
|---|---|---|
| Muzzle | 2,250 fps | 2,360 ft-lb |
| 100 yards | 1,873 fps | 1,636 ft-lb |
| 200 yards | 1,544 fps | 1,111 ft-lb |
| 300 yards | 1,274 fps | 757 ft-lb |
The progression shows how much velocity and energy change during flight. A muzzle-energy figure describes one point, while a downrange table provides context for the cartridge’s hunting role. Neither should be interpreted as a guarantee of field performance.
Federal’s product page does not identify the test-barrel length used for these figures. CM’s rifle has a 16-inch barrel, so this 400 Legend Guide retains the distinction between advertised ammunition performance and results measured from the actual host. An exact CM15 velocity should come from testing rather than an assumed barrel-length correction.
Hunting Applications and Practical Limitations
Winchester’s introduction places the cartridge in hunting situations within 300 yards. That is the manufacturer’s general description of its role, rather than a universal maximum distance for every load, rifle, and hunter.
Woodland openings, field edges, and similar environments provide context for a cartridge intended for short- to medium-distance hunting. Its suitability still depends on the particular ammunition and conditions, rather than simply the presence of a large-diameter bullet.
This 400 Legend Guide separates three ideas: accuracy, retained energy, and bullet behavior. Accuracy describes precision; energy describes a physical quantity; bullet construction governs how a projectile is intended to behave. One cannot substitute for the others when assessing an ammunition claim.
A manufacturer’s trajectory or energy table also does not reveal every bullet’s expansion threshold. Use the load’s documented intended application, and avoid assigning a guaranteed hunting range solely from an energy number.
Recoil and Rifle Fit
Winchester characterizes the cartridge as offering moderate recoil. That description is part of its appeal for hunters seeking a substantial straight-wall round without treating maximum recoil as a desirable feature.
Felt recoil depends on the complete firearm, ammunition, and fit. Rifle weight and stock geometry affect the experience, so cartridge-level marketing figures should not become an exact recoil claim for the CM15.
Fit matters during both range use and time outdoors. A comfortable rifle can support regular practice, but comfort is not an accuracy specification. The rifle’s actual precision must remain distinct from general claims about a cartridge’s recoil or shootability.
400 Legend Guide: CM15 Configuration
Chattahoochee Munitions manufactures complete CM15 rifles with these shared specifications:
- Platform: CM15 / AR15
- Chambering: 400 Legend
- Barrel length: 16 inches
- Twist rate: 1:16
- Gas system: Midlength
- Finishes: Black Tungsten, FDE Metallic, and Cobalt Kinetics Green
- Magazine offering: DURAMAG SS, 10 rounds
- CM suppressor recommendation: Flow-through
The three finishes retain the same barrel length, twist, and gas-system length. Individual product pages provide the remaining component specifications and available selections.
A 1:16 twist means the rifling completes one turn in sixteen inches. Midlength describes the gas-system configuration, while 16 inches describes the barrel. These are distinct specifications, even though they appear together in the rifle’s description.
Dedicated Magazine Design
CM offers the 400 Legend Magazine — DURAMAG SS 10-Round. It uses a 410 stainless steel body, T-360 coating, and cartridge-specific internal rib geometry.
As explained on DURAMAG’s manufacturer page, the body and follower carry caliber markings for identification. Its follower design supports consistent cartridge presentation, and the magazine uses an EverFlex spring.
Receiver fit alone does not establish magazine compatibility. The cartridge stack and internal geometry must also match the chambering. The dedicated model gives this rifle family its own clearly identified magazine rather than relying on a generic AR15 designation.
400 Legend Guide: Suppressor Considerations
CM recommends flow-through suppressors for the 400 Legend CM15. Evaluate a particular model by its manufacturer-approved cartridge rating, bore clearance, mounting interface, and host requirements.
The .40-caliber projectile makes bore compatibility a central consideration. A suppressor’s general category or brand name is not enough to establish suitability. Confirm the actual model’s rating rather than assuming another rifle-caliber suppressor will work.
Suppressing supersonic ammunition reduces muzzle blast but does not remove the ballistic crack. Subsonic ammunition addresses velocity, while the suppressor addresses muzzle sound. Neither term establishes reliable cycling in every semi-automatic host.
This guide does not claim that CM’s 16-inch midlength configuration cycles the 300-grain Super Suppressed load. The existence of that factory ammunition and CM’s flow-through recommendation are separate facts.
400 Legend Guide: Frequently Asked Questions
When was the cartridge introduced?
Winchester publicly announced it in April 2023.
What barrel and gas system does CM use?
The CM15 family uses a 16-inch barrel, 1:16 twist, and midlength gas system across all three finishes.
Are Power-Shok and Power-Point the same load?
No. They are different manufacturer lines. The examples covered here are Federal’s 210-grain Power-Shok and Winchester’s 215-grain Power-Point.
Are the ballistic figures measured from a CM15?
No. The table contains Federal’s published reference figures.
Where can I find the rifles and matching magazine?
Explore Hall of Legends for the CM15 finish options and dedicated 10-round magazine.