Load Specifications
Load data in caliber 7.21 Firebird with .284 | 177gr | RWS ID Classic bullet and 38 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ADI AR 2218, Ramshot LRT and Alliant Reloder-50.
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: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 82% | 60,321 psi | 90% | 2907 fps | 100% |
| Accurate 8700 | <<locked>> | 98% | 58,566 psi | 88% | 3002 fps | 99.8% |
| ADI AR 2213 | <<locked>> | 82% | 60,249 psi | 90% | 3025 fps | 100% |
| ADI AR 2217 | <<locked>> | 88% | 56,840 psi | 85% | 2963 fps | 100% |
| ADI AR 2218 | <<locked>> | 92% | 58,421 psi | 88% | 3117 fps | 100% |
| ADI AR 2225 | <<locked>> | 90% | 57,595 psi | 86% | 2989 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 82% | 59,146 psi | 89% | 2904 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 84% | 57,029 psi | 85% | 2943 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 88% | 56,043 psi | 84% | 3018 fps | 99.8% |
| Alliant Reloder-50 | <<locked>> | 92% | 56,971 psi | 85% | 3025 fps | 99.6% |
| Baschieri & Pellagri 109 | <<locked>> | 84% | 59,669 psi | 89% | 2989 fps | 100% |
| Bofors RP15 | <<locked>> | 82% | 56,521 psi | 85% | 2953 fps | 100% |
| Bofors RP30 | <<locked>> | 86% | 56,913 psi | 85% | 2976 fps | 100% |
| Hodgdon H1000 | <<locked>> | 86% | 58,030 psi | 87% | 2976 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 84% | 57,464 psi | 86% | 3048 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,450 psi | 58% | 1919 fps | 100% |
| Hodgdon US 869 | <<locked>> | 96% | 58,653 psi | 88% | 3005 fps | 97.3% |
| IMR 7828 SSC | <<locked>> | 82% | 59,059 psi | 89% | 3012 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 88% | 60,336 psi | 90% | 2953 fps | 98.6% |
| IMR 8133 Enduron | <<locked>> | 94% | 60,321 psi | 90% | 3041 fps | 100% |
| Lovex D100 | <<locked>> | 90% | 58,943 psi | 88% | 2963 fps | 97.7% |
| Lovex S071 | <<locked>> | 86% | 58,987 psi | 88% | 2890 fps | 100% |
| Norma 217 | <<locked>> | 92% | 58,378 psi | 88% | 3002 fps | 100% |
| Ramshot LRT | <<locked>> | 92% | 57,479 psi | 86% | 3045 fps | 97.2% |
| Ramshot Magnum | <<locked>> | 84% | 59,567 psi | 89% | 2959 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,479 psi | 59% | 1962 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 84% | 58,276 psi | 87% | 3028 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 86% | 57,087 psi | 86% | 3012 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 90% | 58,943 psi | 88% | 2963 fps | 97.7% |
| SNPE Vectan SP 13 | <<locked>> | 98% | 59,814 psi | 90% | 3005 fps | 99.7% |
| Vihtavuori 20N29ᴾ | <<locked>> | 100% | 57,174 psi | 86% | 2986 fps | 98.6% |
| Vihtavuori 24N41 | <<locked>> | 94% | 59,059 psi | 89% | 3012 fps | 97.3% |
| Vihtavuori N165 | <<locked>> | 82% | 57,058 psi | 86% | 2881 fps | 100% |
| Vihtavuori N170 | <<locked>> | 86% | 56,811 psi | 85% | 2936 fps | 99.1% |
| Vihtavuori N565 | <<locked>> | 84% | 58,421 psi | 88% | 2989 fps | 100% |
| Vihtavuori N568 | <<locked>> | 86% | 57,203 psi | 86% | 3015 fps | 100% |
| Vihtavuori N570 | <<locked>> | 88% | 59,248 psi | 89% | 3091 fps | 99.8% |
| Winchester Supreme 780 | <<locked>> | 82% | 60,292 psi | 90% | 2940 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 80% | 56,434 psi | 85% | 2854 fps | 100% |
| Accurate 8700 | <<locked>> | 86% | 37,753 psi | 57% | 2618 fps | 95.4% |
| ADI AR 2213 | <<locked>> | 80% | 56,260 psi | 84% | 2966 fps | 100% |
| ADI AR 2217 | <<locked>> | 80% | 42,960 psi | 64% | 2730 fps | 99.8% |
| ADI AR 2218 | 88.4 gr | 80% | 37,057 psi | 56% | 2687 fps | 95.8% |
| ADI AR 2225 | <<locked>> | 80% | 40,408 psi | 61% | 2703 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 80% | 55,506 psi | 83% | 2854 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 49,705 psi | 75% | 2835 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 80% | 41,698 psi | 63% | 2746 fps | 97.3% |
| Alliant Reloder-50 | 92 gr | 82% | 39,508 psi | 59% | 2687 fps | 95.9% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 52,373 psi | 79% | 2871 fps | 99.5% |
| Bofors RP15 | <<locked>> | 80% | 53,026 psi | 79% | 2897 fps | 100% |
| Bofors RP30 | <<locked>> | 80% | 46,557 psi | 70% | 2805 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 46,833 psi | 70% | 2799 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 80% | 49,734 psi | 75% | 2923 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,950 psi | 43% | 1719 fps | 100% |
| Hodgdon US 869 | <<locked>> | 92% | 51,039 psi | 77% | 2877 fps | 95.5% |
| IMR 7828 SSC | <<locked>> | 80% | 55,259 psi | 83% | 2956 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 80% | 46,630 psi | 70% | 2720 fps | 95.9% |
| IMR 8133 Enduron | <<locked>> | 80% | 37,666 psi | 56% | 2635 fps | 98.9% |
| Lovex D100 | <<locked>> | 84% | 47,674 psi | 71% | 2769 fps | 95.1% |
| Lovex S071 | <<locked>> | 80% | 48,863 psi | 73% | 2740 fps | 100% |
| Norma 217 | <<locked>> | 80% | 38,624 psi | 58% | 2661 fps | 100% |
| Ramshot LRT | 97 gr | 88% | 49,690 psi | 74% | 2904 fps | 95.2% |
| Ramshot Magnum | <<locked>> | 80% | 51,445 psi | 77% | 2844 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,791 psi | 45% | 1759 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 49,995 psi | 75% | 2900 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 45,629 psi | 68% | 2815 fps | 99.5% |
| Shooters World 50 BMG | <<locked>> | 84% | 47,674 psi | 71% | 2769 fps | 95.1% |
| SNPE Vectan SP 13 | <<locked>> | 86% | 39,769 psi | 60% | 2644 fps | 95.8% |
| Vihtavuori 20N29 | <<locked>> | 92% | 43,163 psi | 65% | 2733 fps | 95.2% |
| Vihtavuori 24N41 | <<locked>> | 90% | 51,198 psi | 77% | 2881 fps | 95.4% |
| Vihtavuori N165 | <<locked>> | 80% | 53,417 psi | 80% | 2828 fps | 100% |
| Vihtavuori N170 | <<locked>> | 80% | 46,412 psi | 70% | 2753 fps | 97.2% |
| Vihtavuori N565 | <<locked>> | 80% | 51,024 psi | 76% | 2871 fps | 100% |
| Vihtavuori N568 | <<locked>> | 80% | 46,325 psi | 69% | 2825 fps | 99.3% |
| Vihtavuori N570 | <<locked>> | 80% | 44,469 psi | 67% | 2822 fps | 97.6% |
| Winchester Supreme 780 | <<locked>> | 80% | 56,405 psi | 85% | 2887 fps | 100% |
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 38 powders for 7.21 Firebird loaded with the .284 | 177gr | RWS ID Classic. ADI AR 2218 delivers the highest muzzle velocity at 3,117 fps; across all powders the maximum-charge window runs from 1,919 fps to 3,117 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 38 of the 38 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (460 MPa), the top charges use 58–90 %, leaving at least 10 % headroom. The 177.0 gr projectile in 0.284" calls for a 1:11.5 twist; slower twists will usually not stabilise this weight. Hodgdon TrailBoss, ReloadSwiss RS 14, Vihtavuori 20N29 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 2218, Ramshot LRT, Alliant Reloder-50 rank at the top here: for 7.21 Firebird with the .284 | 177gr | RWS ID Classic 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.