Reliable 350 Legend reloading data is available through the Hodgdon Reloading Data Center, the Hornady Handbook of Cartridge Reloading, and the Lyman AR Reloading Handbook.
Published 350 Legend load data normally includes the specific 0.355-inch bullet design, powder type, starting and maximum charge weights, expected muzzle velocity, and cartridge overall length.
Common 350 Legend bullet weights covered by published data range from 145-grain full metal jackets up to 180-grain soft points for hunting, plus heavy 250-grain projectiles designed for subsonic use.
Results will naturally vary between sources due to differences in the exact bullet profile, powder lot, brass case capacity, small rifle primer brand, test barrel length, and atmospheric conditions.
350 Legend Reloading Data
| Bullet | Bullet Weight | Powder | Published Starting Load | Published Maximum Load | Published Velocity | Pressure (Max) | Primer & Case | Cartridge Overall Length (COL) | Barrel Length / Firearm | Source |
| Hornady SP | 170 grain | Hodgdon Lil’ Gun | 27.0 gr | 27.9 gr | 2,307 fps | 45,900 PSI | Small Rifle / Win | 2.240″ | 16.00″ / Universal | Hodgdon |
| Hornady SP | 170 grain | Winchester 296 | 24.0 gr | 26.7 gr | 2,221 fps | 51,600 PSI | Small Rifle / Win | 2.240″ | 16.00″ / Universal | Hodgdon |
| Sierra Bullet | Not Listed | Hodgdon H110 | 23.5 gr | 26.1 gr | Not Listed | Not Listed | Small Rifle | Not Listed | 16.00″ / Universal | Sierra Bullets |
| Sierra Bullet | Not Listed | IMR 4227 | 24.7 gr | 26.6 gr | Not Listed | Not Listed | Small Rifle | Not Listed | 16.00″ / Universal | Sierra Bullets |
| Sierra Bullet | Not Listed | Alliant MP-300 | 24.6 gr | 26.8 gr | Not Listed | Not Listed | Small Rifle | Not Listed | 16.00″ / Universal | Sierra Bullets |
Understanding The 350 Legend Reloading Data
To safely develop a 350 Legend load recipe, handloaders must understand the specific variables that dictate straight-walled cartridge performance:
- Starting load:The minimum recommended 350 Legend powder charge. Always begin load development here to establish a safe baseline before incrementally working up.
- Maximum published load: The absolute powder limit tested by the ballistic laboratory. Exceeding this figure risks severe overpressure.
- Velocity: The speed of the bullet in feet per second (fps) measured at the muzzle or a designated distance from the test barrel.
- Pressure:The 350 Legend has a SAAMI maximum average pressure (MAP) limit of 55,000 PSI. This is exceptionally high for a straight-walled cartridge, requiring strict adherence to published limits.
- Bullet weight: The mass of the projectile in grains.
- Powder: The specific propellant chemistry and burn rate. Never substitute powders, as fast-burning magnum pistol powders used in this cartridge spike pressure rapidly.
- Barrel length: The length of the test barrel, which for 350 Legend reloading data is frequently 16 inches.
- Firearm used for testing:Typically a universal receiver laboratory barrel, though some manuals use off-the-shelf AR-15s or bolt-action rifles.
- Test conditions: Altitude, humidity, and temperature variables present during laboratory pressure testing.
- Cartridge overall length (COL): The total length of the loaded round. Headspacing on the case mouth makes COL critical for proper chambering and internal case volume.
Different sources publish varying results because they may use brass cases with different internal volumes, a different lot of 350 Legend powder, or slightly tighter test chambers.
350 Legend Bullet Weight Reloading Data
When exploring 350 Legend bullet weights, reloaders must strictly adhere to 0.355-inch diameter projectiles rather than traditional 0.358-inch rifle bullets.
- 125 grain to 145 grain: These lighter bullets are often used for plinking and target shooting. Data for 145-grain FMJs replicates factory Winchester loads.
- 150 grain to 160 grain:Common mid-weight projectiles (such as the 160-grain Fusion or Hornady FTX) intended for deer hunting.
- 170 grain to 180 grain: The most thoroughly documented hunting weights. Hodgdon publishes extensive data for the 170-grain Hornady SP and 180-grain Winchester Power-Point.
- 250+ grain: Specialized heavy bullets designed exclusively for subsonic 350 Legend reloading, typically paired with specific powders like Hodgdon CFE BLK to keep velocities below the speed of sound.
Do not assume 9mm pistol bullets (which are 0.355-inch) can be substituted freely for hunting; while they fit the bore, their thin jackets often fail violently at 350 Legend velocity.
350 Legend Powder Reloading Data
The 350 Legend performs best with fast-burning rifle powders and slow-burning magnum pistol powders.
| Powder | Bullet | Bullet Weight | Published Starting Load | Published Maximum Load | Published Velocity | Source |
| Hodgdon Lil’ Gun | Hornady SP | 170 grain | 27.0 gr | 27.9 gr | 2,307 fps | Hodgdon |
| Winchester 296 | Hornady SP | 170 grain | 24.0 gr | 26.7 gr | 2,221 fps | Hodgdon |
| Hodgdon H110 | Sierra Bullet | Not Listed | 23.5 gr | 26.1 gr | Not Listed | Sierra |
| IMR 4227 | Sierra Bullet | Not Listed | 24.7 gr | 26.6 gr | Not Listed | Sierra |
Never apply a 350 Legend powder charge from one bullet to a different bullet of the same weight. A monolithic copper bullet or a projectile with a longer bearing surface will generate significantly more pressure than a standard lead-core jacketed bullet.
350 Legend Bullet And Powder Combinations
Safe 350 Legend load development relies on precise component combinations.
- Bullet diameter: The cartridge is uniquely designed for 0.355-inch bullets. Using standard .35 caliber (0.358-inch) rifle bullets will cause dangerous pressure spikes and chambering failures.
- Case capacity and seating depth: The straight-walled case has limited powder capacity. Seating a bullet deeper than the published COL dangerously compresses the powder charge.
- Primer:350 Legend reloading data exclusively requires Small Rifle primers to handle the 55,000 PSI maximum average pressure without piercing or flattening.
- Crimp: Because the 350 Legend headspaces on the case mouth, it requires a taper crimp. Applying a heavy roll crimp will ruin the headspace and cause misfires.
- Brass stretch:Unlike pistol cases, the 55,000 PSI operating pressure causes 350 Legend cases to stretch when fired and resized, making regular trimming to uniform length mandatory.
350 Legend Velocity From Published Data
Published 350 Legend velocity figures reflect strictly controlled laboratory testing.
| Bullet | Bullet Weight | Powder | Published Load | Muzzle Velocity | Barrel Length | Firearm | Source |
| Hornady SP | 170 grain | Lil’ Gun | 27.9 gr (Max) | 2,307 fps | 16.00″ | Universal Receiver | Hodgdon |
| Hornady SP | 170 grain | W296 | 26.7 gr (Max) | 2,221 fps | 16.00″ | Universal Receiver | Hodgdon |
| Factory Ammo | 170 grain | Factory | Factory Load | 2,200 fps | 20.00″ | Test Barrel | Hornady |
Distinguish clearly between manufacturer-published velocities and independent chronograph testing. Some users report that maximum published Hodgdon loads using Lil’ Gun cause loose primer pockets in personal AR-15s, highlighting the need to work up carefully from starting charges.
350 Legend Reloading Data By Barrel Length
Barrel length directly impacts 350 Legend velocity. While standard universal receiver data is often captured using 16-inch barrels, hunting rifles commonly utilize 16-inch to 20-inch barrels. Hornady’s factory 170-grain American Whitetail ammunition is tested in a 20-inch barrel, yielding 2,200 fps. Shooters firing the same loads from shorter 16-inch AR-15 barrels will experience a corresponding velocity drop, underscoring why one barrel’s velocity cannot be universally expected across all platforms.
350 Legend Energy And Ballistics
The 350 Legend is optimized for short-to-medium range energy transfer. Using Hornady’s published ballistics for their 170-grain InterLock American Whitetail load from a 20-inch test barrel:
- Muzzle velocity:2,200 fps
- Muzzle energy: 1,843 ft-lbs
- 100-yard velocity:1,827 fps
- 100-yard energy: 1,271 ft-lbs
With lower ballistic coefficients than bottlenecked rifle cartridges, 350 Legend bullets shed velocity quickly, making it a dedicated 200-yard and under hunting cartridge.
Manufacturer Data vs Independent Testing
Reloaders consulting a 350 Legend load data chart will encounter:
- Manufacturer-published data:Verified in a laboratory using piezo-electric sensors to guarantee pressures stay safely below the 55,000 PSI limit.
- Independent testing: Velocities gathered by handloaders over commercial chronographs. This verifies speed but cannot measure internal chamber pressure.
Independently recorded field results often differ from manuals because consumer rifles feature varying gas port sizes, chamber tolerances, and barrel lengths. Priority must always remain with official, pressure-tested manufacturer limits.
350 Legend Pressure And Safety
Safety is paramount when using 350 Legend reloading data. The 55,000 PSI SAAMI specification is uniquely high for a straight-walled, rebated-rim cartridge.
Never substitute standard 0.358-inch rifle bullets into a 350 Legend load recipe; the oversized bullets will dangerously spike pressure. Furthermore, because the case headspaces on the mouth, brass must be trimmed to the exact recommended length to prevent the cartridge from wedging into the rifling. Reloaders must never exceed maximum published loads, as pressure signs in the AR-15 platform (such as loose primer pockets and bulged cases) often appear suddenly and catastrophically.
Best Sources For 350 Legend Reloading Data
The most authoritative sources for safe 350 Legend load development include:
- Hodgdon Reloading Data Center: Provides extensive, free online data for Winchester, Hodgdon, and IMR powders.
- Hornady Handbook of Cartridge Reloading: Offers comprehensive component specificity for their 0.355-inch InterLock and FTX bullets.
- Lyman AR Reloading Handbook (2nd Edition):A dedicated manual containing pressure-tested data for modern AR calibers, including the 350 Legend.
- Sierra Bullets:Publishes dedicated PDF load data for their projectiles using powders like H110, IMR 4227, and MP-300.
Common 350 Legend Reloading Data Questions
Where can I find 350 Legend reloading data?
Authoritative data is available in the Hornady Reloading Handbook, the Lyman AR Reloading Handbook 2nd Edition, and online via the Hodgdon Reloading Data Center.
What powders are used in published 350 Legend data?
Common powders include Hodgdon Lil’ Gun, H110, Winchester 296, IMR 4227, Accurate 1680, and Hodgdon CFE BLK (often used for subsonic loads).
What bullet weights have 350 Legend reloading data?
Data exists for bullet weights ranging from 125-grain copper hollow points to 180-grain hunting soft points, up to 250-grain projectiles for subsonic applications.
What is the best source for 350 Legend reloading data Hodgdon?
The official Hodgdon Reloading Data Center provides the most up-to-date and thoroughly pressure-tested data for all Hodgdon, IMR, and Winchester brand powders.
Why does 350 Legend reloading data vary between sources?
Variations happen due to differences in bullet bearing surface, powder lots, brass thickness, test barrel tolerances, and testing environment conditions.
Does barrel length affect 350 Legend velocity?
Yes. A 20-inch test barrel will record higher muzzle velocities than a 16-inch AR-15 barrel using the exact same load.
Can the same powder charge be used with a different bullet?
No. Different bullet profiles, materials, and bearing surfaces alter case capacity and friction, which dramatically changes chamber pressure.
What is the difference between starting and maximum published load data?
The starting load is the safe baseline charge to begin load development. The maximum load is the absolute highest pressure limit recorded safely by the ballistic laboratory.
Where can I find pressure-tested 350 Legend data?
Pressure-tested data is published by major powder and bullet manufacturers, notably Hodgdon, Hornady, Sierra, and Lyman.
Does Hodgdon publish 350 Legend reloading data?
Yes. Hodgdon provides extensive data for their Lil’ Gun, H110, and CFE BLK powders, as well as Winchester 296.
Does Hornady publish 350 Legend reloading data?
Yes. Hornady publishes data specifically tailored to their 0.355-inch projectiles, available in their Handbook of Cartridge Reloading and official app.
Does Nosler publish 350 Legend reloading data?
While Nosler produces reloading manuals, specialized AR cartridge data for the 350 Legend is more comprehensively covered by Hornady, Lyman, and Hodgdon.
Does Alexander Arms publish 350 Legend data?
No. Alexander Arms developed the .50 Beowulf and 6.5 Grendel. The 350 Legend was developed by Winchester, so official load data should be sourced from Winchester/Hodgdon or major manual publishers.