Load Specifications
Load data in caliber 7.21 Firebird with .284 | 140gr | Ferrobull Tripple Expand Jagd bullet and 52 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon Retumbo, ADI AR 2218 and Vihtavuori N570.
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>> | 86% | 57,464 psi | 86% | 3166 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 49,792 psi | 75% | 3123 fps | 96.7% |
| Accurate MAGPRO | <<locked>> | 84% | 57,087 psi | 86% | 3287 fps | 99.6% |
| ADI AR 2209 | <<locked>> | 84% | 58,798 psi | 88% | 3271 fps | 100% |
| ADI AR 2213 | <<locked>> | 86% | 57,682 psi | 86% | 3287 fps | 99.9% |
| ADI AR 2217 | <<locked>> | 94% | 57,217 psi | 86% | 3264 fps | 100% |
| ADI AR 2218 | <<locked>> | 98% | 58,349 psi | 87% | 3402 fps | 99.2% |
| ADI AR 2225 | <<locked>> | 96% | 56,840 psi | 85% | 3287 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 58,363 psi | 87% | 3258 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 86% | 58,044 psi | 87% | 3278 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 88% | 60,002 psi | 90% | 3232 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 90% | 57,188 psi | 86% | 3258 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 82% | 57,130 psi | 86% | 3264 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 55,825 psi | 84% | 3294 fps | 98.4% |
| Alliant Reloder-50 | <<locked>> | 98% | 55,854 psi | 84% | 3281 fps | 98% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 58,088 psi | 87% | 3241 fps | 98.9% |
| Bofors RP15 | <<locked>> | 88% | 57,421 psi | 86% | 3268 fps | 100% |
| Bofors RP30 | <<locked>> | 92% | 56,971 psi | 85% | 3274 fps | 100% |
| Bofors RP5 | <<locked>> | 86% | 58,044 psi | 87% | 3278 fps | 100% |
| Hodgdon H1000 | <<locked>> | 92% | 58,697 psi | 88% | 3287 fps | 100% |
| Hodgdon H4831 | <<locked>> | 86% | 60,307 psi | 90% | 3278 fps | 99.9% |
| Hodgdon H4831 SC | <<locked>> | 86% | 59,146 psi | 89% | 3258 fps | 99.8% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 58,740 psi | 88% | 3159 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 90% | 56,811 psi | 85% | 3356 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,739 psi | 57% | 2123 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 86% | 60,205 psi | 90% | 3251 fps | 99.9% |
| IMR 7828 SSC | <<locked>> | 88% | 60,278 psi | 90% | 3337 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 92% | 58,827 psi | 88% | 3192 fps | 96.2% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 59,451 psi | 89% | 3327 fps | 100% |
| Lovex S071 | <<locked>> | 92% | 59,567 psi | 89% | 3199 fps | 100% |
| Norma 217 | <<locked>> | 98% | 57,072 psi | 86% | 3287 fps | 100% |
| Norma MRP | <<locked>> | 84% | 58,465 psi | 88% | 3294 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 57,653 psi | 86% | 3291 fps | 100% |
| Ramshot Magnum | <<locked>> | 88% | 56,231 psi | 84% | 3209 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,754 psi | 58% | 2172 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 57,957 psi | 87% | 3337 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 57,043 psi | 86% | 3301 fps | 99.7% |
| Rottweil R 904 | <<locked>> | 84% | 58,900 psi | 88% | 3235 fps | 100% |
| Rottweil R 905 | <<locked>> | 84% | 58,088 psi | 87% | 3248 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 51,750 psi | 78% | 3136 fps | 96.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 57,711 psi | 87% | 3245 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 56,550 psi | 85% | 3159 fps | 99.7% |
| Somchem S385 | <<locked>> | 84% | 58,276 psi | 87% | 3212 fps | 100% |
| Vihtavuori N165 | <<locked>> | 88% | 58,537 psi | 88% | 3196 fps | 100% |
| Vihtavuori N170 | <<locked>> | 92% | 58,030 psi | 87% | 3225 fps | 97.5% |
| Vihtavuori N555 | <<locked>> | 84% | 57,609 psi | 86% | 3202 fps | 100% |
| Vihtavuori N560 | <<locked>> | 84% | 57,740 psi | 87% | 3301 fps | 99.8% |
| Vihtavuori N565 | <<locked>> | 90% | 58,929 psi | 88% | 3291 fps | 99.9% |
| Vihtavuori N568 | <<locked>> | 92% | 57,377 psi | 86% | 3304 fps | 99.5% |
| Vihtavuori N570 | <<locked>> | 94% | 58,943 psi | 88% | 3376 fps | 98.6% |
| Winchester StaBALL HD | <<locked>> | 86% | 57,406 psi | 86% | 3271 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 86% | 58,450 psi | 88% | 3212 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% | 46,717 psi | 70% | 2989 fps | 100% |
| Accurate 8700 | <<locked>> | 98% | 46,021 psi | 69% | 3048 fps | 95.6% |
| Accurate MAGPRO | <<locked>> | 80% | 49,197 psi | 74% | 3143 fps | 98.5% |
| ADI AR 2209 | <<locked>> | 80% | 51,140 psi | 77% | 3143 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 80% | 46,485 psi | 70% | 3081 fps | 98.8% |
| ADI AR 2217 | <<locked>> | 80% | 34,432 psi | 52% | 2785 fps | 95.6% |
| ADI AR 2218 | 101.9 gr | 92% | 46,180 psi | 69% | 3153 fps | 96.3% |
| ADI AR 2225 | <<locked>> | 80% | 31,662 psi | 47% | 2746 fps | 97.5% |
| Alliant Reloder-19 | <<locked>> | 80% | 50,995 psi | 76% | 3130 fps | 99.8% |
| Alliant Reloder-22 | <<locked>> | 80% | 47,166 psi | 71% | 3084 fps | 99.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 45,847 psi | 69% | 3005 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 39,958 psi | 60% | 2943 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 80% | 52,808 psi | 79% | 3199 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 88% | 44,309 psi | 66% | 3064 fps | 95.5% |
| Alliant Reloder-50 | <<locked>> | 94% | 47,790 psi | 72% | 3123 fps | 96% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 44,353 psi | 66% | 2979 fps | 95.9% |
| Bofors RP15 | <<locked>> | 80% | 43,801 psi | 66% | 3012 fps | 99% |
| Bofors RP30 | <<locked>> | 80% | 37,231 psi | 56% | 2871 fps | 96.7% |
| Bofors RP5 | <<locked>> | 80% | 47,166 psi | 71% | 3084 fps | 99.6% |
| Hodgdon H1000 | <<locked>> | 80% | 37,594 psi | 56% | 2874 fps | 97.5% |
| Hodgdon H4831 | <<locked>> | 80% | 48,820 psi | 73% | 3077 fps | 98.8% |
| Hodgdon H4831 SC | <<locked>> | 80% | 48,022 psi | 72% | 3061 fps | 98.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 55,013 psi | 82% | 3107 fps | 100% |
| Hodgdon Retumbo | 83.6 gr | 80% | 39,030 psi | 59% | 2999 fps | 98.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,297 psi | 42% | 1903 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 49,385 psi | 74% | 3061 fps | 99% |
| IMR 7828 SSC | <<locked>> | 80% | 45,310 psi | 68% | 3064 fps | 98.6% |
| IMR 7977 Enduron | <<locked>> | 90% | 55,172 psi | 83% | 3130 fps | 95.3% |
| IMR 8133 Enduron | <<locked>> | 84% | 33,808 psi | 51% | 2789 fps | 95.1% |
| Lovex S071 | <<locked>> | 80% | 40,103 psi | 60% | 2854 fps | 99.7% |
| Norma 217 | <<locked>> | 80% | 29,385 psi | 44% | 2674 fps | 95.2% |
| Norma MRP | <<locked>> | 80% | 50,473 psi | 76% | 3159 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 45,861 psi | 69% | 3077 fps | 99% |
| Ramshot Magnum | <<locked>> | 80% | 41,234 psi | 62% | 2936 fps | 99.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,124 psi | 44% | 1952 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 38,696 psi | 58% | 2969 fps | 99.5% |
| ReloadSwiss RS 80 | <<locked>> | 82% | 38,464 psi | 58% | 2917 fps | 95.6% |
| Rottweil R 904 | <<locked>> | 80% | 51,590 psi | 77% | 3110 fps | 99.5% |
| Rottweil R 905 | <<locked>> | 80% | 50,720 psi | 76% | 3123 fps | 99.9% |
| SNPE Vectan SP 13 | <<locked>> | 98% | 48,022 psi | 72% | 3064 fps | 95.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 50,386 psi | 76% | 3120 fps | 99.8% |
| Somchem S361 | <<locked>> | 80% | 52,852 psi | 79% | 3097 fps | 99.3% |
| Somchem S385 | <<locked>> | 80% | 50,952 psi | 76% | 3087 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 44,672 psi | 67% | 2956 fps | 99.5% |
| Vihtavuori N170 | <<locked>> | 88% | 50,575 psi | 76% | 3091 fps | 95.8% |
| Vihtavuori N555 | <<locked>> | 80% | 50,531 psi | 76% | 3091 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 49,966 psi | 75% | 3163 fps | 99% |
| Vihtavuori N565 | <<locked>> | 80% | 41,510 psi | 62% | 2953 fps | 97.4% |
| Vihtavuori N568 | <<locked>> | 82% | 39,421 psi | 59% | 2936 fps | 95.3% |
| Vihtavuori N570 | 95.5 gr | 88% | 47,152 psi | 71% | 3150 fps | 95.9% |
| Winchester StaBALL HD | <<locked>> | 80% | 45,382 psi | 68% | 3074 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 47,224 psi | 71% | 3018 fps | 99.6% |
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 52 powders for 7.21 Firebird loaded with the .284 | 140gr | Ferrobull Tripple Expand Jagd. ADI AR 2218 delivers the highest muzzle velocity at 3,402 fps; across all powders the maximum-charge window runs from 2,123 fps to 3,402 fps. Accurate 8700 gives the best case fill at 100 %, and 52 of the 52 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 140.0 gr projectile in 0.284" calls for a 1:11.5 twist; slower twists will usually not stabilise this weight. Accurate 8700, Hodgdon TrailBoss, IMR 8133 Enduron 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. Hodgdon Retumbo, ADI AR 2218, Vihtavuori N570 rank at the top here: for 7.21 Firebird with the .284 | 140gr | Ferrobull Tripple Expand Jagd 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.