Load Specifications
Load data in caliber 7.21 Firebird with .284 | 180gr | Berger BT Target bullet and 42 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 Ramshot LRT.
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% | 59,538 psi | 89% | 2874 fps | 100% |
| Accurate 8700 | <<locked>> | 98% | 57,450 psi | 86% | 2966 fps | 99.7% |
| ADI AR 2213 | <<locked>> | 82% | 59,451 psi | 89% | 2989 fps | 100% |
| ADI AR 2217 | <<locked>> | 90% | 60,002 psi | 90% | 2986 fps | 100% |
| ADI AR 2218 | <<locked>> | 92% | 57,246 psi | 86% | 3081 fps | 100% |
| ADI AR 2225 | <<locked>> | 90% | 56,623 psi | 85% | 2956 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 82% | 60,046 psi | 90% | 2979 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 82% | 58,465 psi | 88% | 2874 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 86% | 60,075 psi | 90% | 2963 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 90% | 59,263 psi | 89% | 3048 fps | 99.9% |
| Alliant Reloder-50 | <<locked>> | 94% | 60,147 psi | 90% | 3058 fps | 99.9% |
| Baschieri & Pellagri 109 | <<locked>> | 84% | 58,856 psi | 88% | 2956 fps | 99.9% |
| Bofors RP15 | <<locked>> | 84% | 59,582 psi | 89% | 2972 fps | 100% |
| Bofors RP30 | <<locked>> | 88% | 59,857 psi | 90% | 2999 fps | 100% |
| Bofors RP5 | <<locked>> | 82% | 60,046 psi | 90% | 2979 fps | 100% |
| Hodgdon H1000 | <<locked>> | 86% | 57,159 psi | 86% | 2943 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 82% | 60,307 psi | 90% | 2959 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 84% | 56,594 psi | 85% | 3012 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,363 psi | 57% | 1896 fps | 100% |
| Hodgdon US 869 | <<locked>> | 96% | 57,653 psi | 86% | 2969 fps | 97.1% |
| IMR 7828 SSC | <<locked>> | 82% | 58,233 psi | 87% | 2979 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 88% | 59,669 psi | 89% | 2920 fps | 98.5% |
| IMR 8133 Enduron | <<locked>> | 94% | 59,393 psi | 89% | 3005 fps | 100% |
| Lovex D100 | <<locked>> | 90% | 58,001 psi | 87% | 2923 fps | 97.6% |
| Lovex S071 | <<locked>> | 86% | 58,189 psi | 87% | 2854 fps | 100% |
| Norma 217 | <<locked>> | 92% | 57,377 psi | 86% | 2969 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 60,336 psi | 90% | 3005 fps | 100% |
| Ramshot LRT | <<locked>> | 92% | 56,449 psi | 85% | 3009 fps | 97% |
| Ramshot Magnum | <<locked>> | 84% | 58,552 psi | 88% | 2927 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,552 psi | 59% | 1939 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 84% | 57,203 psi | 86% | 2992 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 88% | 60,321 psi | 90% | 3038 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 90% | 58,001 psi | 87% | 2923 fps | 97.6% |
| SNPE Vectan SP 13 | <<locked>> | 98% | 58,668 psi | 88% | 2969 fps | 99.6% |
| Vihtavuori 20N29ᴾ | <<locked>> | 100% | 56,188 psi | 84% | 2953 fps | 98.5% |
| Vihtavuori 24N41 | <<locked>> | 94% | 58,117 psi | 87% | 2976 fps | 97.1% |
| Vihtavuori N165 | <<locked>> | 84% | 60,075 psi | 90% | 2900 fps | 100% |
| Vihtavuori N170 | <<locked>> | 88% | 59,828 psi | 90% | 2959 fps | 99.4% |
| Vihtavuori N565 | <<locked>> | 84% | 57,580 psi | 86% | 2956 fps | 100% |
| Vihtavuori N568 | <<locked>> | 88% | 60,292 psi | 90% | 3038 fps | 100% |
| Vihtavuori N570 | <<locked>> | 88% | 58,131 psi | 87% | 3054 fps | 99.8% |
| Winchester Supreme 780 | <<locked>> | 82% | 59,596 psi | 89% | 2910 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% | 55,796 psi | 84% | 2822 fps | 100% |
| Accurate 8700 | <<locked>> | 86% | 37,043 psi | 56% | 2585 fps | 95.3% |
| ADI AR 2213 | <<locked>> | 80% | 55,419 psi | 83% | 2930 fps | 100% |
| ADI AR 2217 | <<locked>> | 80% | 42,322 psi | 63% | 2697 fps | 99.8% |
| ADI AR 2218 | 86.2 gr | 80% | 36,376 psi | 55% | 2651 fps | 95.6% |
| ADI AR 2225 | <<locked>> | 80% | 39,755 psi | 60% | 2674 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 56,086 psi | 84% | 2923 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 80% | 54,781 psi | 82% | 2825 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 49,008 psi | 73% | 2802 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 80% | 40,930 psi | 61% | 2713 fps | 97.1% |
| Alliant Reloder-50 | <<locked>> | 82% | 38,711 psi | 58% | 2654 fps | 95.8% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 51,822 psi | 78% | 2841 fps | 99.5% |
| Bofors RP15 | <<locked>> | 80% | 52,373 psi | 79% | 2867 fps | 100% |
| Bofors RP30 | <<locked>> | 80% | 45,934 psi | 69% | 2772 fps | 100% |
| Bofors RP5 | <<locked>> | 80% | 56,086 psi | 84% | 2923 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 46,064 psi | 69% | 2766 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 80% | 56,318 psi | 84% | 2900 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 80% | 49,008 psi | 73% | 2894 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,906 psi | 43% | 1696 fps | 100% |
| Hodgdon US 869 | <<locked>> | 92% | 50,154 psi | 75% | 2841 fps | 95.3% |
| IMR 7828 SSC | <<locked>> | 80% | 54,433 psi | 82% | 2920 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 80% | 46,137 psi | 69% | 2687 fps | 95.8% |
| IMR 8133 Enduron | <<locked>> | 80% | 37,028 psi | 56% | 2605 fps | 98.8% |
| Lovex D100 | <<locked>> | 86% | 50,285 psi | 75% | 2795 fps | 95.9% |
| Lovex S071 | <<locked>> | 80% | 48,283 psi | 72% | 2710 fps | 100% |
| Norma 217 | <<locked>> | 80% | 37,927 psi | 57% | 2628 fps | 99.9% |
| Ramshot Grand | <<locked>> | 80% | 56,101 psi | 84% | 2946 fps | 100% |
| Ramshot LRT | 94.7 gr | 88% | 48,965 psi | 73% | 2874 fps | 95.1% |
| Ramshot Magnum | <<locked>> | 80% | 50,546 psi | 76% | 2808 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,762 psi | 45% | 1736 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 49,066 psi | 74% | 2867 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 44,817 psi | 67% | 2782 fps | 99.5% |
| Shooters World 50 BMG | <<locked>> | 86% | 50,285 psi | 75% | 2795 fps | 95.9% |
| SNPE Vectan SP 13 | <<locked>> | 86% | 39,015 psi | 58% | 2612 fps | 95.6% |
| Vihtavuori 20N29 | <<locked>> | 92% | 42,235 psi | 63% | 2697 fps | 95% |
| Vihtavuori 24N41 | <<locked>> | 90% | 50,386 psi | 76% | 2848 fps | 95.3% |
| Vihtavuori N165 | <<locked>> | 80% | 52,837 psi | 79% | 2799 fps | 100% |
| Vihtavuori N170 | <<locked>> | 80% | 45,832 psi | 69% | 2720 fps | 97.2% |
| Vihtavuori N565 | <<locked>> | 80% | 50,430 psi | 76% | 2841 fps | 100% |
| Vihtavuori N568 | <<locked>> | 80% | 45,498 psi | 68% | 2789 fps | 99.3% |
| Vihtavuori N570 | 84.5 gr | 80% | 43,758 psi | 66% | 2789 fps | 97.5% |
| Winchester Supreme 780 | <<locked>> | 80% | 55,666 psi | 83% | 2854 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 43 powders for 7.21 Firebird loaded with the .284 | 180gr | Berger BT Target. ADI AR 2218 delivers the highest muzzle velocity at 3,081 fps; across all powders the maximum-charge window runs from 1,896 fps to 3,081 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 43 of the 43 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 180.0 gr projectile in 0.284" calls for a 1:10.0 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, Vihtavuori N570, Ramshot LRT rank at the top here: for 7.21 Firebird with the .284 | 180gr | Berger BT Target they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Hodgdon 50BMG burn incompletely and react more sensitively to barrel length and temperature. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.