Load Specifications
Load data in caliber .450 Bushmaster with .452 | 255gr | Rim Rock SWC Top Shelf bullet and 8 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Lovex S053, Vihtavuori N110 and SNPE Vectan BA6 1/2.
Important Notice: DO NOT go below Minimum Charge or above Maximum Charge. Since we have no control over the equipment and components used, any responsibility and liability for the results achieved is rejected.
Only powders/loads that match the current filter criteria are displayed: max pressure of a load ≤ 90% of max. standardized pressure, fill rate ≥ 80% and propellant combustion ≥ 95%. Use the sliders above the tables to adjust these thresholds.
Charge: Powder weight in grains. Start with the minimum load and work up carefully.
FR (Fill Rate): Case fill as a percentage. Values above 100% mean compressed loads.
MaxP / %: Maximum chamber pressure in bar and as a percentage of the standardized maximum for this caliber.
V(0): Muzzle velocity in feet per second (fps) at the standardized barrel length.
z (Powder Burn): Estimated propellant combustion percentage at bullet exit.
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Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate No. 11 FS | <<locked>> | 82% | 33,721 psi | 86% | 2172 fps | 96.4% |
| ADI AR 2205 | <<locked>> | 84% | 34,374 psi | 88% | 2116 fps | 98.2% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 25,150 psi | 64% | 1421 fps | 100% |
| Lovex S053 | <<locked>> | 94% | 34,142 psi | 87% | 2205 fps | 98.3% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 24,018 psi | 61% | 1450 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 96% | 33,881 psi | 87% | 2116 fps | 100% |
| Vihtavuori N110 | <<locked>> | 88% | 33,982 psi | 87% | 2175 fps | 100% |
| Vihtavuori N120ᴾ | <<locked>> | 100% | 32,677 psi | 83% | 2221 fps | 97.1% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate No. 11 FS | <<locked>> | 80% | 31,473 psi | 80% | 2129 fps | 95.6% |
| ADI AR 2205 | <<locked>> | 80% | 30,255 psi | 77% | 2034 fps | 97.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 17,927 psi | 46% | 1266 fps | 100% |
| Lovex S053 | 37.2 gr | 84% | 25,208 psi | 64% | 2011 fps | 95.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 17,231 psi | 44% | 1296 fps | 100% |
| SNPE Vectan BA6 1/2 | 32.4 gr | 80% | 21,422 psi | 55% | 1860 fps | 99.5% |
| Vihtavuori N110 | 33.8 gr | 80% | 26,368 psi | 67% | 2028 fps | 99.7% |
| Vihtavuori N120 | <<locked>> | 94% | 27,354 psi | 70% | 2103 fps | 95% |
Recommended = one of the top powders for this cartridge and bullet combination.
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 17 powders for .450 Bushmaster loaded with the .452 | 255gr | Rim Rock SWC Top Shelf. ADI AR 2207 delivers the highest muzzle velocity at 2,238 fps; across all powders the maximum-charge window runs from 1,421 fps to 2,238 fps. ADI AR 2207 gives the best case fill at 100 %, and 17 of the 17 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (270 MPa), the top charges use 61–90 %, leaving at least 10 % headroom. ADI AR 2207, Alliant Reloder-7, Hodgdon TrailBoss reach 100 % fill or more at maximum charge, so these are compressed loads: they need a long drop tube to seat cleanly and react sensitively to the case capacity of your own brass lot. Lovex S053, Vihtavuori N110, SNPE Vectan BA6 1/2 rank at the top here: for .450 Bushmaster with the .452 | 255gr | Rim Rock SWC Top Shelf they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Alliant Reloder-7, IMR 4227, Lovex D060 burn incompletely and react more sensitively to barrel length and temperature. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.