Load Specifications
Load data in caliber .221 Rem. Fireball with .224 | 55gr | Sierra Tipped VarmintKing bullet and 12 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Lovex S053, IMR 4227 and ADI AR 2207.
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% | 40,538 psi | 87% | 2638 fps | 98.6% |
| ADI AR 2205 | <<locked>> | 84% | 40,785 psi | 88% | 2566 fps | 99.6% |
| ADI AR 2207ᴾ | <<locked>> | 100% | 40,422 psi | 87% | 2753 fps | 98.6% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 27,760 psi | 60% | 1693 fps | 100% |
| IMR 4227 | <<locked>> | 92% | 41,539 psi | 90% | 2664 fps | 97.5% |
| Lovex S053 | <<locked>> | 94% | 41,771 psi | 90% | 2680 fps | 99.7% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 27,050 psi | 58% | 1732 fps | 100% |
| ReloadSwiss RS 36 | <<locked>> | 94% | 41,872 psi | 90% | 2717 fps | 97.5% |
| Shooters World SOCOM | <<locked>> | 84% | 39,987 psi | 86% | 2615 fps | 96.2% |
| SNPE Vectan BA6 1/2 | <<locked>> | 96% | 40,785 psi | 88% | 2543 fps | 100% |
| Vihtavuori N110 | <<locked>> | 88% | 41,989 psi | 90% | 2631 fps | 100% |
| Vihtavuori N120ᴾ | <<locked>> | 100% | 40,843 psi | 88% | 2720 fps | 99.4% |
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% | 38,174 psi | 82% | 2592 fps | 98.1% |
| ADI AR 2205 | <<locked>> | 80% | 36,216 psi | 78% | 2477 fps | 99.1% |
| ADI AR 2207 | 13.5 gr | 90% | 29,892 psi | 64% | 2516 fps | 95.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 20,073 psi | 43% | 1512 fps | 100% |
| IMR 4227 | 12.6 gr | 86% | 34,534 psi | 74% | 2520 fps | 95.6% |
| Lovex S053 | 11.5 gr | 80% | 27,934 psi | 60% | 2372 fps | 96.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 19,696 psi | 42% | 1549 fps | 100% |
| ReloadSwiss RS 36 | <<locked>> | 88% | 34,983 psi | 75% | 2575 fps | 95.7% |
| Shooters World SOCOM | <<locked>> | 82% | 37,623 psi | 81% | 2569 fps | 95.5% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 26,484 psi | 57% | 2257 fps | 100% |
| Vihtavuori N110 | <<locked>> | 80% | 33,112 psi | 71% | 2470 fps | 100% |
| Vihtavuori N120 | <<locked>> | 86% | 26,977 psi | 58% | 2402 fps | 95.6% |
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 12 powders for .221 Rem. Fireball loaded with the .224 | 55gr | Sierra Tipped VarmintKing. ADI AR 2207 delivers the highest muzzle velocity at 2,753 fps; across all powders the maximum-charge window runs from 1,693 fps to 2,753 fps. ADI AR 2207 gives the best case fill at 100 %, and 12 of the 12 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (320 MPa), the top charges use 58–90 %, leaving at least 10 % headroom. The 55.0 gr projectile in 0.224" calls for a 1:8.5 twist; slower twists will usually not stabilise this weight. ADI AR 2207, Hodgdon TrailBoss, ReloadSwiss RS 14 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, IMR 4227, ADI AR 2207 rank at the top here: for .221 Rem. Fireball with the .224 | 55gr | Sierra Tipped VarmintKing 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.