Reliable .450 Bushmaster reloading data is published in authoritative manuals from Hornady, Barnes, Lyman, and the Hodgdon Reloading Data Center. Published data normally includes the specific 0.452-inch bullet design, fast-burning powder type, starting and maximum charge weights, expected velocity, and cartridge overall length. Common bullet weights covered by .450 Bushmaster load data range from 225-grain lightweight hollow points up to 300-grain heavy hunting projectiles. Results naturally vary between sources due to differences in bullet profile, exact powder burn rates, brass case capacity, test barrel length, and atmospheric testing conditions.
.450 Bushmaster 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 FTX | 225 grain | Hodgdon Lil’ Gun | 35.0 gr | 40.0 gr | 2,367 fps | 38,300 PSI | Small Rifle / Hornady | 2.250″ | 24.00″ / Universal | Hodgdon |
| Hornady FTX | 225 grain | Hodgdon H110 | 36.5 gr | 41.5 gr | 2,323 fps | 38,300 PSI | Small Rifle / Hornady | 2.250″ | 24.00″ / Universal | Hodgdon |
| Hornady FTX | 250 grain | Hodgdon Lil’ Gun | 32.5 gr | 37.8 gr | 2,197 fps | 38,000 PSI | Small Rifle / Hornady | 2.225″ | 24.00″ / Universal | Hodgdon |
| Hornady FTX | 250 grain | Hodgdon H110 | 34.0 gr | 39.5 gr | 2,171 fps | 38,200 PSI | Small Rifle / Hornady | 2.225″ | 24.00″ / Universal | Hodgdon |
| Hornady FTX | 250 grain | IMR 4227 | 34.0 gr | 39.5 gr | 2,012 fps | 38,200 PSI | Small Rifle / Hornady | 2.225″ | 24.00″ / Universal | Hodgdon |
| Barnes TSX | 275 grain | Hodgdon Lil’ Gun | 30.0 gr | 34.5 gr | 2,090 fps | 38,300 PSI | Small Rifle / Hornady | 2.235″ | 24.00″ / Universal | Hodgdon |
| Barnes TSX | 275 grain | Winchester 296 | 31.0 gr | 35.5 gr | 2,060 fps | 38,300 PSI | Small Rifle / Hornady | 2.235″ | 24.00″ / Universal | Hodgdon |
| Hornady XTP Mag | 300 grain | Hodgdon Lil’ Gun | 28.5 gr | 34.5 gr | 1,989 fps | 38,400 PSI | Small Rifle / Hornady | 2.110″ | 24.00″ / Universal | Hodgdon |
| Hornady XTP Mag | 300 grain | Hodgdon H110 | 30.0 gr | 34.5 gr | 1,940 fps | 38,400 PSI | Small Rifle / Hornady | 2.110″ | 24.00″ / Universal | Hodgdon |
| Hornady XTP Mag | 300 grain | Accurate No. 9 | 24.8 gr | 27.5 gr | 1,749 fps | 38,432 PSI | Small Rifle / Hornady | 2.110″ | 20.00″ / Universal | Western Powders |
Understanding The .450 Bushmaster Reloading Data
To safely develop a .450 Bushmaster load recipe, handloaders must understand the specific variables that dictate this straight-walled AR-15 cartridge:
- Starting load: The minimum safe powder charge. With magnum pistol powders like H110, reloaders must never drop below the starting load to prevent dangerous hang-fires.
- Maximum published load: The absolute powder limit tested by the ballistic laboratory. Exceeding this limit in an AR-15 will shear bolt lugs and destroy the firearm.
- Velocity: The bullet speed in feet per second (fps) measured at the muzzle.
- Pressure: The SAAMI maximum average pressure for the .450 Bushmaster is 38,500 PSI, mandated by the bolt thrust limitations of the AR-15 platform.
- Bullet weight: The mass of the 0.452-inch projectile in grains.
- Powder: The specific propellant type. Fast-burning magnum pistol powders are required.
- Barrel length: Test barrels for the .450 Bushmaster vary, with Hodgdon utilizing 24-inch barrels and other manuals utilizing 16-inch or 20-inch barrels.
- Firearm used for testing: Universal receiver test barrels or production AR-15 rifles.
- Test conditions: Altitude, humidity, and temperature variables during pressure testing.
- Cartridge overall length (COL): The total length of the loaded cartridge. Standard AR-15 magazines strictly restrict the COL to a maximum of 2.260 inches.
Different sources produce varying results because they may use cases with differing internal volumes, different primer brands, and varying test barrel lengths.
.450 Bushmaster Bullet Weight Reloading Data
When researching .450 Bushmaster reloading data, handloaders must strictly use 0.452-inch diameter bullets intended for pistol calibers or specifically designed for the Bushmaster, rather than 0.458-inch bullets used in the 45-70 Government.
- 225 grain: Lightweight projectiles designed for rapid expansion and high velocity. The Hornady 225-grain FTX can reach nearly 2,400 fps, offering a flatter trajectory for deer hunting out to 200 yards.
- 250 grain: The universal standard for the cartridge, heavily popularized by factory Hornady Custom ammunition. The 250-grain FTX strikes the perfect balance of velocity (around 2,200 fps), penetration, and manageable recoil in the AR-15 platform.
- 275 grain: Mid-heavy weights, notably the solid copper Barnes TSX, which is extensively documented in Hodgdon’s manual. Solid copper bullets offer extreme weight retention for deep penetration on large game like elk or bear.
- 300 grain: The heavy end of standard published data. The 300-grain Hornady XTP Mag is commonly used for dangerous game or thick brush hunting, achieving roughly 1,900 fps while delivering massive kinetic energy.
Do not assume a 250-grain lead bullet uses the same powder charge as a 250-grain jacketed bullet, nor should you ever attempt to squeeze an oversized 0.458-inch rifle bullet into the .450 Bushmaster case, as this will cause catastrophic overpressure.
.450 Bushmaster Powder Reloading Data
Because the .450 Bushmaster uses a large, straight-walled case but operates at moderate rifle pressures, it relies entirely on slow-burning magnum pistol powders.
| Powder | Bullet | Bullet Weight | Published Starting Load | Published Maximum Load | Published Velocity | Source |
| Hodgdon Lil’ Gun | Hornady FTX | 250 grain | 32.5 gr | 37.8 gr | 2,197 fps | Hodgdon |
| Hodgdon H110 | Hornady FTX | 250 grain | 34.0 gr | 39.5 gr | 2,171 fps | Hodgdon |
| Winchester 296 | Barnes TSX | 275 grain | 31.0 gr | 35.5 gr | 2,060 fps | Hodgdon |
| IMR 4227 | Hornady FTX | 250 grain | 34.0 gr | 39.5 gr | 2,012 fps | Hodgdon |
| Accurate No. 9 | Hornady XTP Mag | 300 grain | 24.8 gr | 27.5 gr | 1,749 fps | Western Powders |
Powders like Lil’ Gun and H110 are heavily featured in the .450 Bushmaster load data chart because they ignite reliably and generate enough gas volume to properly cycle an AR-15’s direct impingement gas system.
.450 Bushmaster Bullet And Powder Combinations
The exact component combinations determine the safety and reliability of .450 Bushmaster load development.
- Primer choice: Unlike many large straight-walled cartridges, the .450 Bushmaster utilizes Small Rifle primers. This leaves more brass webbing at the case head to safely contain the 38,500 PSI pressure. Utilizing a small rifle magnum primer is often recommended when igniting heavy charges of H110 or W296 in cold hunting conditions.
- Case capacity and seating depth: Seating a blunt 300-grain bullet deeper than the published COL reduces internal case capacity and aggressively spikes chamber pressure.
- Bullet construction: Solid copper bullets (like the Barnes TSX) are longer and create more bore friction than standard lead-core bullets of identical weight, generating higher pressures faster and requiring reduced powder charges.
- Crimp: The .450 Bushmaster headspaces on the case mouth. It strictly requires a taper crimp. Applying a heavy roll crimp will ruin the headspace, allowing the cartridge to slip too deeply into the chamber and resulting in light primer strikes or misfires.
.450 Bushmaster Velocity From Published Data
Published .450 Bushmaster velocity figures depend entirely on the barrel length utilized by the laboratory.
| Bullet | Bullet Weight | Powder | Published Load | Muzzle Velocity | Barrel Length | Firearm | Source |
| Hornady FTX | 225 grain | Lil’ Gun | 40.0 gr (Max) | 2,367 fps | 24.00″ | Universal Receiver | Hodgdon |
| Hornady FTX | 250 grain | H110 | 39.5 gr (Max) | 2,171 fps | 24.00″ | Universal Receiver | Hodgdon |
| Hornady XTP Mag | 300 grain | Accurate No. 9 | 27.5 gr (Max) | 1,749 fps | 20.00″ | Universal Receiver | Western Powders |
It is crucial to distinguish between unvented 24-inch universal receiver barrels and the much more common 16-inch AR-15 barrels. Do not present a 24-inch laboratory velocity as achievable from a standard 16-inch brush gun.
.450 Bushmaster Reloading Data By Barrel Length
Barrel length directly impacts the velocity a reloader will achieve. While Hodgdon utilizes 24-inch barrels to establish maximum ballistic potential, most consumer .450 Bushmaster rifles are sold with 16-inch to 20-inch barrels.
When firing Hodgdon’s maximum 250-grain FTX load (2,197 fps) from a 24-inch barrel, the powder achieves a complete burn. If that exact same load is fired from a 16-inch AR-15 carbine, the velocity drops to approximately 2,000 to 2,050 fps. Reloaders must clearly identify their test firearm and barrel length when verifying ballistic trajectories, as the heavy bullets will drop significantly faster when launched from shorter barrels.
.450 Bushmaster Energy And Ballistics
The .450 Bushmaster is optimized for devastating short-to-medium range energy transfer, making it a favorite for deer and hog hunting in straight-wall restricted states. Using verified manufacturer data equivalents from a 20-inch barrel:
- 250-grain FTX (at 2,100 fps):
- Muzzle energy: ~2,448 ft-lbs
- 100-yard velocity: ~1,735 fps
- 100-yard energy: ~1,671 ft-lbs
- 300-grain XTP (at 1,900 fps):
- Muzzle energy: ~2,404 ft-lbs
- 100-yard velocity: ~1,520 fps
- 100-yard energy: ~1,539 ft-lbs
Because of the blunt, low ballistic coefficient (BC) projectiles, the .450 Bushmaster sheds its kinetic energy rapidly. It is generally considered a 200-yard cartridge, beyond which the trajectory resembles a rainbow and energy drops sharply.
Manufacturer Data vs Independent Testing
When researching a .450 Bushmaster load data chart, handloaders will encounter:
- Manufacturer-published reloading data: Officially pressure-tested in a laboratory using piezo-electric sensors to guarantee loads stay safely under the 38,500 PSI limit.
- Independent chronograph testing: Velocities recorded by handloaders over real AR-15s or bolt-action rifles. This verifies speed but cannot measure internal chamber pressure.
- User-submitted load reports: Internet forum recipes that often irresponsibly push past published maximums to chase velocity.
Independently measured results frequently differ from published data because consumer AR-15s feature varying gas port sizes, buffer weights, and barrel tolerances. Priority must always remain with official, pressure-tested manufacturer data.
.450 Bushmaster Pressure And Safety
Safety is paramount when using .450 Bushmaster reloading data due to the cartridge’s rebated rim and the structural limitations of the AR-15 platform.
The 38,500 PSI pressure limit must be strictly respected. The AR-15 bolt face must be heavily opened up to accommodate the .450 Bushmaster case head (which matches the .284 Winchester). This leaves the bolt lugs exceptionally thin. Exceeding published maximum powder charges will result in sheared bolt lugs and a destroyed rifle.
Furthermore, handloaders utilizing ball powders like H110 or W296 must never reduce their powder charges by more than 3% below the published maximum load. These powders require high load density to ignite properly; under-charging them can cause a primer to push the bullet into the barrel without fully igniting the powder, creating a dangerous bore obstruction. Always apply a proper taper crimp to ensure the cartridge headspaces correctly on the case mouth.
Best Sources For .450 Bushmaster Reloading Data
The strongest and most authoritative sources for safe .450 Bushmaster load development include:
- Hodgdon Reloading Data Center: Provides the most extensive, free online data specifically highlighting the exceptional performance of Hodgdon Lil’ Gun and H110.
- Hornady Handbook of Cartridge Reloading: The definitive source for loading Hornady’s 0.452-inch FTX, InterLock, and XTP Mag projectiles, offering data optimized for the AR-15.
- Lyman AR Reloading Handbook: Offers highly transparent data specifically tailored to modern sporting rifles, including detailed information on taper crimping and gas system reliability.
- Barnes Reloading Manual: The best source for lead-free, solid copper TSX data.
Common .450 Bushmaster Reloading Data Questions
Where can I find .450 Bushmaster reloading data?
Authoritative data is published in the Hornady Reloading Handbook, the Lyman AR Reloading Handbook, and free online via the Hodgdon Reloading Data Center.
What powders are used in published .450 Bushmaster data?
Common powders include Hodgdon Lil’ Gun, Hodgdon H110, Winchester 296, IMR 4227, Accurate 1680, and Accurate No. 9.
What bullet weights have .450 Bushmaster reloading data?
Published data covers 225-grain lightweight expanding bullets up to heavy 300-grain hunting projectiles, with the 250-grain weight being the most common.
What is the best source for .450 Bushmaster reloading data Hodgdon?
The official Hodgdon Reloading Data Center provides the most rigorously pressure-tested data for all Hodgdon, IMR, and Winchester brand powders.
Why does .450 Bushmaster reloading data vary between sources?
Variations occur due to differences in bullet profile, solid copper versus lead-core bearing surfaces, differing laboratory chamber tolerances, and 24-inch versus 16-inch test barrel lengths.
Does barrel length affect .450 Bushmaster velocity?
Yes. A 24-inch test barrel will consistently yield velocities 150 to 200 fps higher than a standard 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 internal case capacity and friction, which dramatically changes chamber pressures.
What is the difference between starting and maximum published load data?
The starting load is the safe baseline for working up a new recipe. The maximum load is the absolute highest pressure limit established safely by a ballistic laboratory.
Where can I find pressure-tested .450 Bushmaster data?
Pressure-tested data is available directly from major bullet and powder manufacturers, including Hornady, Hodgdon, Barnes, and Lyman.
Does Hodgdon publish .450 Bushmaster reloading data?
Yes. Hodgdon provides extensive data specifically developed for the cartridge, covering their Lil’ Gun, H110, and IMR 4227 powders.
Does Hornady publish .450 Bushmaster reloading data?
Yes. Hornady publishes incredibly comprehensive load recipes tailored specifically for their 0.452-inch projectiles, including the flagship 250-grain FTX.
Does Nosler publish .450 Bushmaster reloading data?
Nosler publishes limited data for .45 caliber pistol bullets, but dedicated AR-15 .450 Bushmaster data is best sourced from Hornady or Hodgdon.
Does Lyman publish .450 Bushmaster data?
Yes. The Lyman AR Reloading Handbook provides extensive, pressure-tested .450 Bushmaster data utilizing a wide variety of bullet and powder brands specifically for semi-automatic use.