Load Specifications
Load data in caliber .221 Rem. Fireball with .224 | 55gr | Sierra SP SemiSp bullet and 16 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ADI AR 2207, Vihtavuori N120 and ReloadSwiss RS 36.
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 |
|---|---|---|---|---|---|---|
| ADI AR 2205 | <<locked>> | 82% | 41,524 psi | 89% | 2631 fps | 99.9% |
| ADI AR 2207 | <<locked>> | 96% | 40,045 psi | 86% | 2799 fps | 99.2% |
| Alliant Reloder-7 | <<locked>> | 94% | 40,277 psi | 87% | 2743 fps | 96.3% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 28,892 psi | 62% | 1759 fps | 100% |
| IMR 4198ᴾ | <<locked>> | 100% | 40,553 psi | 87% | 2746 fps | 96.6% |
| IMR 4227 | <<locked>> | 88% | 39,972 psi | 86% | 2690 fps | 98% |
| Lovex D060 | <<locked>> | 82% | 41,205 psi | 89% | 2726 fps | 96.7% |
| Lovex S053 | <<locked>> | 90% | 41,220 psi | 89% | 2720 fps | 99.9% |
| Norma 200ᴾ | <<locked>> | 100% | 41,887 psi | 90% | 2835 fps | 97.2% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 28,210 psi | 61% | 1795 fps | 100% |
| ReloadSwiss RS 36 | <<locked>> | 90% | 41,481 psi | 89% | 2766 fps | 98.2% |
| Shooters World Buffalo Rifle | <<locked>> | 82% | 41,205 psi | 89% | 2726 fps | 96.7% |
| Shooters World SOCOM | <<locked>> | 82% | 40,973 psi | 88% | 2694 fps | 97.4% |
| SNPE Vectan BA6 1/2 | <<locked>> | 92% | 39,842 psi | 86% | 2569 fps | 100% |
| Vihtavuori N110 | <<locked>> | 84% | 40,538 psi | 87% | 2654 fps | 100% |
| Vihtavuori N120 | <<locked>> | 96% | 40,379 psi | 87% | 2766 fps | 99.7% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| ADI AR 2205 | <<locked>> | 80% | 38,638 psi | 83% | 2579 fps | 99.8% |
| ADI AR 2207 | 13.9 gr | 84% | 27,615 psi | 60% | 2503 fps | 95.6% |
| Alliant Reloder-7 | <<locked>> | 92% | 37,405 psi | 81% | 2684 fps | 95.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 21,074 psi | 45% | 1575 fps | 100% |
| IMR 4198 | <<locked>> | 96% | 36,535 psi | 79% | 2661 fps | 95.3% |
| IMR 4227 | <<locked>> | 80% | 31,270 psi | 67% | 2493 fps | 95.5% |
| Lovex D060 | <<locked>> | 80% | 39,044 psi | 84% | 2680 fps | 96.1% |
| Lovex S053 | <<locked>> | 80% | 30,719 psi | 66% | 2493 fps | 98.5% |
| Norma 200 | <<locked>> | 94% | 34,838 psi | 75% | 2690 fps | 95.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 20,653 psi | 45% | 1611 fps | 100% |
| ReloadSwiss RS 36 | 13.8 gr | 80% | 30,443 psi | 66% | 2516 fps | 95% |
| Shooters World Buffalo Rifle | <<locked>> | 80% | 39,044 psi | 84% | 2680 fps | 96.1% |
| Shooters World SOCOM | <<locked>> | 80% | 38,812 psi | 84% | 2651 fps | 96.8% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 29,008 psi | 63% | 2356 fps | 100% |
| Vihtavuori N110 | <<locked>> | 80% | 36,056 psi | 78% | 2572 fps | 100% |
| Vihtavuori N120 | 13.2 gr | 80% | 24,685 psi | 53% | 2379 fps | 95.5% |
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 16 powders for .221 Rem. Fireball loaded with the .224 | 55gr | Sierra SP SemiSp. Norma 200 delivers the highest muzzle velocity at 2,835 fps; across all powders the maximum-charge window runs from 1,759 fps to 2,835 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 16 of the 16 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (320 MPa), the top charges use 61–90 %, leaving at least 10 % headroom. The 55.0 gr projectile in 0.224" calls for a 1:13.0 twist; slower twists will usually not stabilise this weight. Hodgdon TrailBoss, IMR 4198, Norma 200 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. ADI AR 2207, Vihtavuori N120, ReloadSwiss RS 36 rank at the top here: for .221 Rem. Fireball with the .224 | 55gr | Sierra SP SemiSp they combine a high case fill with complete burn and sit in the upper velocity band. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.