Load Specifications
Load data in caliber 7.21 Firebird with .284 | 168gr | Nosler AccuBond Long Range bullet and 49 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ADI AR 2218, Vihtavuori N570 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>> | 84% | 60,162 psi | 90% | 2972 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 57,305 psi | 86% | 3048 fps | 99.4% |
| Accurate MAGPRO | <<locked>> | 82% | 59,698 psi | 89% | 3104 fps | 100% |
| ADI AR 2213 | <<locked>> | 84% | 60,017 psi | 90% | 3087 fps | 100% |
| ADI AR 2217 | <<locked>> | 92% | 60,162 psi | 90% | 3077 fps | 100% |
| ADI AR 2218 | <<locked>> | 94% | 57,174 psi | 86% | 3166 fps | 99.8% |
| ADI AR 2225 | <<locked>> | 92% | 56,362 psi | 84% | 3045 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 60,278 psi | 90% | 3051 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 82% | 56,710 psi | 85% | 3022 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 84% | 58,929 psi | 88% | 2972 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 88% | 60,176 psi | 90% | 3058 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 59,451 psi | 89% | 3140 fps | 99.8% |
| Alliant Reloder-50 | <<locked>> | 96% | 59,988 psi | 90% | 3136 fps | 99.6% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 59,698 psi | 89% | 3051 fps | 99.8% |
| Bofors RP15 | <<locked>> | 86% | 60,104 psi | 90% | 3071 fps | 100% |
| Bofors RP30 | <<locked>> | 90% | 60,089 psi | 90% | 3094 fps | 100% |
| Bofors RP5 | <<locked>> | 82% | 56,710 psi | 85% | 3022 fps | 100% |
| Hodgdon H1000 | <<locked>> | 88% | 57,493 psi | 86% | 3035 fps | 100% |
| Hodgdon H4831 | <<locked>> | 82% | 58,131 psi | 87% | 3015 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 82% | 57,159 psi | 86% | 2999 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 86% | 56,478 psi | 85% | 3107 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,174 psi | 57% | 1949 fps | 100% |
| Hodgdon US 869 | <<locked>> | 98% | 57,899 psi | 87% | 3048 fps | 96.3% |
| IMR 4955 Enduron | <<locked>> | 82% | 58,015 psi | 87% | 2989 fps | 100% |
| IMR 7828 SSC | <<locked>> | 84% | 58,871 psi | 88% | 3077 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 88% | 56,826 psi | 85% | 2953 fps | 97.4% |
| IMR 8133 Enduron | <<locked>> | 96% | 59,277 psi | 89% | 3094 fps | 100% |
| Lovex D100 | <<locked>> | 92% | 58,682 psi | 88% | 3012 fps | 97% |
| Lovex S071 | <<locked>> | 88% | 58,610 psi | 88% | 2949 fps | 100% |
| Norma 217 | <<locked>> | 94% | 57,101 psi | 86% | 3054 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 56,521 psi | 85% | 3041 fps | 100% |
| Ramshot LRT | <<locked>> | 94% | 56,579 psi | 85% | 3091 fps | 96.2% |
| Ramshot Magnum | <<locked>> | 86% | 59,088 psi | 89% | 3022 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,334 psi | 59% | 1998 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 86% | 57,232 psi | 86% | 3087 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 88% | 56,173 psi | 84% | 3064 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 92% | 58,682 psi | 88% | 3012 fps | 97% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 58,871 psi | 88% | 3054 fps | 99.3% |
| SNPE Vectan Tubal 8000 | <<locked>> | 82% | 60,046 psi | 90% | 3041 fps | 100% |
| Vihtavuori 20N29ᴾ | <<locked>> | 100% | 52,083 psi | 78% | 2963 fps | 97% |
| Vihtavuori 24N41 | <<locked>> | 96% | 58,450 psi | 88% | 3061 fps | 96.4% |
| Vihtavuori N165 | <<locked>> | 84% | 56,956 psi | 85% | 2943 fps | 100% |
| Vihtavuori N170 | <<locked>> | 88% | 56,681 psi | 85% | 2992 fps | 98.6% |
| Vihtavuori N560 | <<locked>> | 82% | 60,176 psi | 90% | 3104 fps | 100% |
| Vihtavuori N565 | <<locked>> | 86% | 58,059 psi | 87% | 3048 fps | 100% |
| Vihtavuori N568 | <<locked>> | 88% | 56,536 psi | 85% | 3071 fps | 100% |
| Vihtavuori N570 | <<locked>> | 90% | 58,291 psi | 87% | 3146 fps | 99.5% |
| Winchester StaBALL HD | <<locked>> | 82% | 56,985 psi | 85% | 3018 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 82% | 56,521 psi | 85% | 2953 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% | 52,736 psi | 79% | 2864 fps | 100% |
| Accurate 8700 | <<locked>> | 90% | 39,726 psi | 60% | 2723 fps | 95.4% |
| Accurate MAGPRO | <<locked>> | 80% | 55,724 psi | 84% | 3038 fps | 100% |
| ADI AR 2213 | <<locked>> | 80% | 52,373 psi | 79% | 2969 fps | 100% |
| ADI AR 2217 | <<locked>> | 80% | 39,436 psi | 59% | 2720 fps | 99% |
| ADI AR 2218 | 89.8 gr | 84% | 39,291 psi | 59% | 2799 fps | 95.9% |
| ADI AR 2225 | <<locked>> | 80% | 36,811 psi | 55% | 2694 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 56,507 psi | 85% | 2995 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 53,084 psi | 80% | 2966 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 80% | 51,808 psi | 78% | 2871 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 45,992 psi | 69% | 2841 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 80% | 37,942 psi | 57% | 2720 fps | 95.2% |
| Alliant Reloder-50 | 93.4 gr | 86% | 41,553 psi | 62% | 2795 fps | 96% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 49,197 psi | 74% | 2874 fps | 98.7% |
| Bofors RP15 | <<locked>> | 80% | 49,371 psi | 74% | 2900 fps | 100% |
| Bofors RP30 | <<locked>> | 80% | 42,917 psi | 64% | 2799 fps | 99.5% |
| Bofors RP5 | <<locked>> | 80% | 53,084 psi | 80% | 2966 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 43,134 psi | 65% | 2795 fps | 99.8% |
| Hodgdon H4831 | <<locked>> | 80% | 54,404 psi | 82% | 2956 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 80% | 53,519 psi | 80% | 2940 fps | 99.9% |
| Hodgdon Retumbo | <<locked>> | 80% | 45,368 psi | 68% | 2920 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,805 psi | 43% | 1749 fps | 100% |
| Hodgdon US 869 | <<locked>> | 96% | 53,838 psi | 81% | 2982 fps | 95.4% |
| IMR 4955 Enduron | <<locked>> | 80% | 54,462 psi | 82% | 2933 fps | 100% |
| IMR 7828 SSC | <<locked>> | 80% | 51,140 psi | 77% | 2953 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 82% | 46,746 psi | 70% | 2772 fps | 95% |
| IMR 8133 Enduron | <<locked>> | 80% | 34,447 psi | 52% | 2618 fps | 97.5% |
| Lovex D100 | <<locked>> | 88% | 50,981 psi | 76% | 2881 fps | 95.1% |
| Lovex S071 | <<locked>> | 80% | 45,498 psi | 68% | 2746 fps | 100% |
| Norma 217 | <<locked>> | 80% | 35,143 psi | 53% | 2644 fps | 99.3% |
| Ramshot Grand | <<locked>> | 80% | 52,460 psi | 79% | 2979 fps | 100% |
| Ramshot LRT | <<locked>> | 92% | 52,678 psi | 79% | 3022 fps | 95.2% |
| Ramshot Magnum | <<locked>> | 80% | 47,471 psi | 71% | 2844 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,617 psi | 44% | 1788 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 45,397 psi | 68% | 2897 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 41,626 psi | 62% | 2795 fps | 98.4% |
| Shooters World 50 BMG | <<locked>> | 88% | 50,981 psi | 76% | 2881 fps | 95.1% |
| SNPE Vectan SP 13 | <<locked>> | 90% | 41,742 psi | 63% | 2743 fps | 95.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 56,188 psi | 84% | 2986 fps | 100% |
| Vihtavuori 20N29 | <<locked>> | 96% | 45,121 psi | 68% | 2828 fps | 95.1% |
| Vihtavuori 24N41 | <<locked>> | 94% | 54,476 psi | 82% | 2995 fps | 95.5% |
| Vihtavuori N165 | <<locked>> | 80% | 49,995 psi | 75% | 2838 fps | 100% |
| Vihtavuori N170 | <<locked>> | 80% | 43,221 psi | 65% | 2743 fps | 95.6% |
| Vihtavuori N560 | <<locked>> | 80% | 56,188 psi | 84% | 3045 fps | 100% |
| Vihtavuori N565 | <<locked>> | 80% | 47,398 psi | 71% | 2867 fps | 99.7% |
| Vihtavuori N568 | <<locked>> | 80% | 42,424 psi | 64% | 2805 fps | 98.1% |
| Vihtavuori N570 | 83.8 gr | 80% | 40,625 psi | 61% | 2799 fps | 95.7% |
| Winchester StaBALL HD | <<locked>> | 80% | 52,895 psi | 79% | 2959 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 52,692 psi | 79% | 2894 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 49 powders for 7.21 Firebird loaded with the .284 | 168gr | Nosler AccuBond Long Range. ADI AR 2218 delivers the highest muzzle velocity at 3,166 fps; across all powders the maximum-charge window runs from 1,949 fps to 3,166 fps. Accurate 8700 gives the best case fill at 100 %, and 49 of the 49 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (460 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 168.0 gr projectile in 0.284" calls for a 1:9.5 twist; slower twists will usually not stabilise this weight. Accurate 8700, 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. ADI AR 2218, Vihtavuori N570, Alliant Reloder-50 rank at the top here: for 7.21 Firebird with the .284 | 168gr | Nosler AccuBond Long Range 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.