Load Specifications
Load data in caliber 7.21 Firebird with .284 | 130gr | Speer Hot-Cor bullet and 51 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 ReloadSwiss RS 80.
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% | 57,696 psi | 86% | 3258 fps | 100% |
| Accurate MAGPRO | <<locked>> | 84% | 56,898 psi | 85% | 3373 fps | 99.3% |
| ADI AR 2209 | <<locked>> | 84% | 58,349 psi | 87% | 3356 fps | 100% |
| ADI AR 2213 | <<locked>> | 86% | 57,232 psi | 86% | 3369 fps | 99.8% |
| ADI AR 2217 | <<locked>> | 94% | 56,855 psi | 85% | 3346 fps | 99.9% |
| ADI AR 2218 | <<locked>> | 98% | 57,914 psi | 87% | 3474 fps | 98.7% |
| ADI AR 2225 | <<locked>> | 96% | 56,347 psi | 84% | 3366 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 57,943 psi | 87% | 3340 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 86% | 57,740 psi | 87% | 3363 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 88% | 59,698 psi | 89% | 3317 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 90% | 56,869 psi | 85% | 3343 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 82% | 56,811 psi | 85% | 3350 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 96% | 60,046 psi | 90% | 3448 fps | 98.7% |
| Alliant Reloder-50 | <<locked>> | 98% | 55,956 psi | 84% | 3360 fps | 97.5% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 57,754 psi | 87% | 3320 fps | 98.4% |
| Bofors RP15 | <<locked>> | 88% | 57,305 psi | 86% | 3353 fps | 100% |
| Bofors RP30 | <<locked>> | 92% | 56,695 psi | 85% | 3360 fps | 99.9% |
| Bofors RP5 | <<locked>> | 86% | 57,740 psi | 87% | 3363 fps | 100% |
| Hodgdon H1000 | <<locked>> | 92% | 58,305 psi | 87% | 3369 fps | 100% |
| Hodgdon H4831 | <<locked>> | 86% | 59,857 psi | 90% | 3360 fps | 99.7% |
| Hodgdon H4831 SC | <<locked>> | 86% | 58,755 psi | 88% | 3340 fps | 99.6% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 58,566 psi | 88% | 3251 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 90% | 56,246 psi | 84% | 3438 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,768 psi | 57% | 2198 fps | 100% |
| IMR 4350 | <<locked>> | 82% | 60,118 psi | 90% | 3323 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 86% | 59,872 psi | 90% | 3333 fps | 99.8% |
| IMR 7828 SSC | <<locked>> | 88% | 59,944 psi | 90% | 3419 fps | 99.9% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 59,248 psi | 89% | 3409 fps | 100% |
| Lovex S071 | <<locked>> | 92% | 59,553 psi | 89% | 3287 fps | 100% |
| Norma 217 | <<locked>> | 98% | 56,768 psi | 85% | 3373 fps | 100% |
| Norma MRP | <<locked>> | 84% | 58,102 psi | 87% | 3383 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 57,276 psi | 86% | 3376 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 90% | 60,350 psi | 90% | 3360 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,783 psi | 58% | 2251 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 57,595 psi | 86% | 3419 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 56,826 psi | 85% | 3379 fps | 99.4% |
| Rottweil R 904 | <<locked>> | 84% | 58,726 psi | 88% | 3323 fps | 99.8% |
| Rottweil R 905 | <<locked>> | 84% | 57,769 psi | 87% | 3333 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 51,706 psi | 78% | 3212 fps | 96.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 57,377 psi | 86% | 3327 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 56,478 psi | 85% | 3241 fps | 99.4% |
| Somchem S385 | <<locked>> | 84% | 58,175 psi | 87% | 3297 fps | 100% |
| Vihtavuori N165 | <<locked>> | 88% | 58,392 psi | 88% | 3281 fps | 100% |
| Vihtavuori N170 | <<locked>> | 92% | 58,073 psi | 87% | 3307 fps | 97% |
| Vihtavuori N555 | <<locked>> | 84% | 57,711 psi | 87% | 3297 fps | 100% |
| Vihtavuori N560 | <<locked>> | 84% | 57,348 psi | 86% | 3383 fps | 99.6% |
| Vihtavuori N565 | <<locked>> | 90% | 58,885 psi | 88% | 3376 fps | 99.8% |
| Vihtavuori N568 | <<locked>> | 92% | 57,029 psi | 85% | 3383 fps | 99.1% |
| Vihtavuori N570 | <<locked>> | 94% | 58,624 psi | 88% | 3455 fps | 98.1% |
| Winchester StaBALL HD | <<locked>> | 86% | 56,927 psi | 85% | 3356 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 86% | 58,102 psi | 87% | 3291 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% | 46,963 psi | 70% | 3074 fps | 100% |
| Accurate MAGPRO | <<locked>> | 80% | 49,110 psi | 74% | 3222 fps | 98% |
| ADI AR 2209 | <<locked>> | 80% | 50,966 psi | 76% | 3225 fps | 99.6% |
| ADI AR 2213 | <<locked>> | 80% | 46,311 psi | 69% | 3159 fps | 98.3% |
| ADI AR 2217 | <<locked>> | 82% | 37,072 psi | 56% | 2933 fps | 96% |
| ADI AR 2218 | 104.2 gr | 92% | 46,079 psi | 69% | 3225 fps | 95.4% |
| ADI AR 2225 | <<locked>> | 80% | 31,836 psi | 48% | 2822 fps | 96.9% |
| Alliant Reloder-19 | <<locked>> | 80% | 50,850 psi | 76% | 3215 fps | 99.6% |
| Alliant Reloder-22 | <<locked>> | 80% | 47,094 psi | 71% | 3166 fps | 99.3% |
| Alliant Reloder-23 | <<locked>> | 80% | 45,730 psi | 69% | 3091 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 39,943 psi | 60% | 3025 fps | 99.9% |
| Alliant Reloder-26 | <<locked>> | 80% | 52,837 psi | 79% | 3287 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 90% | 47,776 psi | 72% | 3215 fps | 95.9% |
| Alliant Reloder-50 | <<locked>> | 94% | 48,022 psi | 72% | 3202 fps | 95.4% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 44,208 psi | 66% | 3054 fps | 95.1% |
| Bofors RP15 | <<locked>> | 80% | 43,700 psi | 66% | 3091 fps | 98.6% |
| Bofors RP30 | <<locked>> | 80% | 37,362 psi | 56% | 2949 fps | 96.1% |
| Bofors RP5 | <<locked>> | 80% | 47,094 psi | 71% | 3166 fps | 99.3% |
| Hodgdon H1000 | <<locked>> | 80% | 37,579 psi | 56% | 2949 fps | 96.8% |
| Hodgdon H4831 | <<locked>> | 80% | 48,805 psi | 73% | 3159 fps | 98.3% |
| Hodgdon H4831 SC | <<locked>> | 80% | 47,863 psi | 72% | 3140 fps | 98.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 54,752 psi | 82% | 3196 fps | 100% |
| Hodgdon Retumbo | 85.5 gr | 80% | 38,972 psi | 58% | 3074 fps | 98.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,427 psi | 43% | 1978 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 56,420 psi | 85% | 3264 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 49,284 psi | 74% | 3143 fps | 98.5% |
| IMR 7828 SSC | <<locked>> | 80% | 45,005 psi | 67% | 3136 fps | 98% |
| IMR 8133 Enduron | <<locked>> | 86% | 36,477 psi | 55% | 2936 fps | 95.6% |
| Lovex S071 | <<locked>> | 80% | 40,321 psi | 60% | 2936 fps | 99.5% |
| Norma 217 | <<locked>> | 82% | 31,981 psi | 48% | 2825 fps | 95.9% |
| Norma MRP | <<locked>> | 80% | 50,401 psi | 76% | 3248 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 45,600 psi | 68% | 3156 fps | 98.5% |
| Ramshot Magnum | <<locked>> | 80% | 41,278 psi | 62% | 3015 fps | 98.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,124 psi | 44% | 2024 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 38,696 psi | 58% | 3045 fps | 99.2% |
| ReloadSwiss RS 80 | 96.9 gr | 84% | 41,742 psi | 63% | 3074 fps | 96.1% |
| Rottweil R 904 | <<locked>> | 80% | 51,517 psi | 77% | 3192 fps | 99.2% |
| Rottweil R 905 | <<locked>> | 80% | 50,502 psi | 76% | 3202 fps | 99.7% |
| SNPE Vectan SP 13 | <<locked>> | 98% | 48,153 psi | 72% | 3143 fps | 95.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 50,154 psi | 75% | 3199 fps | 99.6% |
| Somchem S361 | <<locked>> | 80% | 52,750 psi | 79% | 3176 fps | 99% |
| Somchem S385 | <<locked>> | 80% | 50,923 psi | 76% | 3173 fps | 99.9% |
| Vihtavuori N165 | <<locked>> | 80% | 44,657 psi | 67% | 3035 fps | 99.2% |
| Vihtavuori N170 | <<locked>> | 88% | 50,517 psi | 76% | 3163 fps | 95.1% |
| Vihtavuori N555 | <<locked>> | 80% | 50,502 psi | 76% | 3179 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 49,850 psi | 75% | 3241 fps | 98.6% |
| Vihtavuori N565 | <<locked>> | 80% | 41,655 psi | 62% | 3031 fps | 96.8% |
| Vihtavuori N568 | <<locked>> | 84% | 42,627 psi | 64% | 3091 fps | 95.8% |
| Vihtavuori N570 | <<locked>> | 88% | 46,934 psi | 70% | 3222 fps | 95.1% |
| Winchester StaBALL HD | <<locked>> | 80% | 45,150 psi | 68% | 3159 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 47,137 psi | 71% | 3097 fps | 99.3% |
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 51 powders for 7.21 Firebird loaded with the .284 | 130gr | Speer Hot-Cor. ADI AR 2218 delivers the highest muzzle velocity at 3,474 fps; across all powders the maximum-charge window runs from 2,198 fps to 3,474 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 51 of the 51 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 130.0 gr projectile in 0.284" calls for a 1:13.5 twist; slower twists will usually not stabilise this weight. Hodgdon TrailBoss, IMR 8133 Enduron, 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. Hodgdon Retumbo, ADI AR 2218, ReloadSwiss RS 80 rank at the top here: for 7.21 Firebird with the .284 | 130gr | Speer Hot-Cor 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.