Load Specifications
Load data in caliber .221 Rem. Fireball with .223 | 55gr | SUS-TAC HP bullet and 11 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 36, ADI AR 2207 and Lovex S053.
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% | 39,682 psi | 86% | 2566 fps | 99.7% |
| ADI AR 2207ᴾ | <<locked>> | 100% | 41,495 psi | 89% | 2795 fps | 99% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 28,036 psi | 60% | 1716 fps | 100% |
| IMR 4227 | <<locked>> | 90% | 40,350 psi | 87% | 2664 fps | 97.6% |
| Lovex S053 | <<locked>> | 92% | 40,770 psi | 88% | 2680 fps | 99.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 27,340 psi | 59% | 1752 fps | 100% |
| ReloadSwiss RS 36 | <<locked>> | 92% | 41,365 psi | 89% | 2730 fps | 97.7% |
| Shooters World SOCOM | <<locked>> | 84% | 41,800 psi | 90% | 2674 fps | 97% |
| SNPE Vectan BA6 1/2 | <<locked>> | 94% | 39,914 psi | 86% | 2546 fps | 100% |
| Vihtavuori N110 | <<locked>> | 86% | 40,306 psi | 87% | 2621 fps | 100% |
| Vihtavuori N120ᴾ | <<locked>> | 100% | 41,829 psi | 90% | 2762 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% | 37,463 psi | 81% | 2523 fps | 99.4% |
| ADI AR 2207 | 13.4 gr | 86% | 27,572 psi | 59% | 2470 fps | 95% |
| Hodgdon TrailBoss | <<locked>> | 80% | 20,537 psi | 44% | 1539 fps | 100% |
| IMR 4227 | <<locked>> | 82% | 31,792 psi | 69% | 2477 fps | 95% |
| Lovex S053 | 11.9 gr | 80% | 28,689 psi | 62% | 2415 fps | 97.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 20,146 psi | 43% | 1575 fps | 100% |
| ReloadSwiss RS 36 | 13.6 gr | 84% | 32,271 psi | 70% | 2533 fps | 95.1% |
| Shooters World SOCOM | <<locked>> | 80% | 36,550 psi | 79% | 2569 fps | 95.6% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 27,354 psi | 59% | 2297 fps | 100% |
| Vihtavuori N110 | <<locked>> | 80% | 34,127 psi | 74% | 2507 fps | 100% |
| Vihtavuori N120 | <<locked>> | 84% | 26,440 psi | 57% | 2405 fps | 95.8% |
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 11 powders for .221 Rem. Fireball loaded with the .223 | 55gr | SUS-TAC HP. ADI AR 2207 delivers the highest muzzle velocity at 2,795 fps; across all powders the maximum-charge window runs from 1,716 fps to 2,795 fps. ADI AR 2207 gives the best case fill at 100 %, and 11 of the 11 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (320 MPa), the top charges use 59–90 %, leaving at least 10 % headroom. The 55.0 gr projectile in 0.223" calls for a 1:10.0 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. ReloadSwiss RS 36, ADI AR 2207, Lovex S053 rank at the top here: for .221 Rem. Fireball with the .223 | 55gr | SUS-TAC HP 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.