Load Specifications
Load data in caliber 7.21 Firebird with .284 | 139gr | Reichenberg HDB Universal bullet and 52 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-33.
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.
A valid access license is required to use the Personalized Load Calculator.
You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 86% | 59,030 psi | 88% | 3199 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 51,329 psi | 77% | 3159 fps | 97.1% |
| Accurate MAGPRO | <<locked>> | 84% | 58,233 psi | 87% | 3317 fps | 99.6% |
| ADI AR 2209 | <<locked>> | 84% | 59,741 psi | 90% | 3291 fps | 100% |
| ADI AR 2213 | <<locked>> | 86% | 58,856 psi | 88% | 3317 fps | 100% |
| ADI AR 2217 | <<locked>> | 94% | 58,465 psi | 88% | 3294 fps | 100% |
| ADI AR 2218 | <<locked>> | 98% | 59,654 psi | 89% | 3435 fps | 99.3% |
| ADI AR 2225 | <<locked>> | 96% | 58,189 psi | 87% | 3314 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 59,321 psi | 89% | 3281 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 86% | 59,364 psi | 89% | 3307 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 86% | 57,392 psi | 86% | 3199 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 90% | 58,523 psi | 88% | 3284 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 82% | 58,479 psi | 88% | 3291 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 57,450 psi | 86% | 3330 fps | 98.7% |
| Alliant Reloder-50 | <<locked>> | 98% | 57,769 psi | 87% | 3323 fps | 98.4% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 58,987 psi | 88% | 3264 fps | 99% |
| Bofors RP15 | <<locked>> | 88% | 58,711 psi | 88% | 3297 fps | 100% |
| Bofors RP30 | <<locked>> | 92% | 58,450 psi | 88% | 3307 fps | 100% |
| Bofors RP5 | <<locked>> | 86% | 59,364 psi | 89% | 3307 fps | 100% |
| Hodgdon H1000 | <<locked>> | 92% | 59,944 psi | 90% | 3314 fps | 100% |
| Hodgdon H4831 | <<locked>> | 84% | 57,261 psi | 86% | 3235 fps | 99.7% |
| Hodgdon H4831 SC | <<locked>> | 86% | 60,263 psi | 90% | 3284 fps | 99.9% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 59,799 psi | 90% | 3182 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 90% | 58,189 psi | 87% | 3386 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,942 psi | 57% | 2133 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 84% | 57,261 psi | 86% | 3212 fps | 99.8% |
| IMR 7828 SSC | <<locked>> | 86% | 57,377 psi | 86% | 3297 fps | 99.9% |
| IMR 7977 Enduron | <<locked>> | 92% | 59,814 psi | 90% | 3215 fps | 96.3% |
| IMR 8133 Enduron | <<locked>> | 98% | 57,029 psi | 85% | 3294 fps | 100% |
| Lovex S071 | <<locked>> | 90% | 57,363 psi | 86% | 3173 fps | 100% |
| Norma 217 | <<locked>> | 98% | 58,697 psi | 88% | 3320 fps | 100% |
| Norma MRP | <<locked>> | 84% | 59,640 psi | 89% | 3320 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 58,987 psi | 88% | 3320 fps | 100% |
| Ramshot Magnum | <<locked>> | 88% | 57,609 psi | 86% | 3238 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,986 psi | 58% | 2182 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 59,393 psi | 89% | 3366 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 58,566 psi | 88% | 3333 fps | 99.8% |
| Rottweil R 904 | <<locked>> | 84% | 60,002 psi | 90% | 3261 fps | 100% |
| Rottweil R 905 | <<locked>> | 84% | 59,190 psi | 89% | 3274 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 53,113 psi | 80% | 3169 fps | 97.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 58,813 psi | 88% | 3268 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 57,682 psi | 86% | 3182 fps | 99.7% |
| Somchem S385 | <<locked>> | 84% | 59,582 psi | 89% | 3238 fps | 100% |
| Vihtavuori N165 | <<locked>> | 88% | 59,770 psi | 90% | 3222 fps | 100% |
| Vihtavuori N170 | <<locked>> | 92% | 59,379 psi | 89% | 3255 fps | 97.7% |
| Vihtavuori N555 | <<locked>> | 84% | 59,146 psi | 89% | 3232 fps | 100% |
| Vihtavuori N560 | <<locked>> | 84% | 58,813 psi | 88% | 3327 fps | 99.9% |
| Vihtavuori N565 | <<locked>> | 88% | 56,492 psi | 85% | 3258 fps | 99.8% |
| Vihtavuori N568 | <<locked>> | 92% | 58,798 psi | 88% | 3337 fps | 99.6% |
| Vihtavuori N570 | <<locked>> | 94% | 60,336 psi | 90% | 3409 fps | 98.8% |
| Winchester StaBALL HD | <<locked>> | 86% | 58,842 psi | 88% | 3301 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 86% | 59,466 psi | 89% | 3235 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% | 48,124 psi | 72% | 3022 fps | 100% |
| Accurate 8700 | <<locked>> | 98% | 47,543 psi | 71% | 3084 fps | 96% |
| Accurate MAGPRO | <<locked>> | 80% | 50,575 psi | 76% | 3179 fps | 98.7% |
| ADI AR 2209 | <<locked>> | 80% | 52,272 psi | 78% | 3166 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 80% | 47,529 psi | 71% | 3110 fps | 99% |
| ADI AR 2217 | <<locked>> | 80% | 35,491 psi | 53% | 2822 fps | 96.1% |
| ADI AR 2218 | 100.1 gr | 90% | 44,034 psi | 66% | 3107 fps | 95.4% |
| ADI AR 2225 | <<locked>> | 80% | 32,895 psi | 49% | 2792 fps | 98.1% |
| Alliant Reloder-19 | <<locked>> | 80% | 51,982 psi | 78% | 3156 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 80% | 48,298 psi | 72% | 3114 fps | 99.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 47,036 psi | 71% | 3035 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 41,249 psi | 62% | 2979 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 80% | 54,346 psi | 81% | 3228 fps | 100% |
| Alliant Reloder-33 | 99.7 gr | 88% | 45,730 psi | 69% | 3104 fps | 96% |
| Alliant Reloder-50 | <<locked>> | 92% | 46,006 psi | 69% | 3094 fps | 95.4% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 45,310 psi | 68% | 3005 fps | 96.2% |
| Bofors RP15 | <<locked>> | 80% | 44,947 psi | 67% | 3045 fps | 99.2% |
| Bofors RP30 | <<locked>> | 80% | 38,493 psi | 58% | 2910 fps | 97.2% |
| Bofors RP5 | <<locked>> | 80% | 48,298 psi | 72% | 3114 fps | 99.7% |
| Hodgdon H1000 | <<locked>> | 80% | 38,667 psi | 58% | 2910 fps | 97.9% |
| Hodgdon H4831 | <<locked>> | 80% | 49,966 psi | 75% | 3107 fps | 98.9% |
| Hodgdon H4831 SC | <<locked>> | 80% | 49,008 psi | 73% | 3087 fps | 98.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 56,086 psi | 84% | 3130 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 80% | 40,350 psi | 60% | 3038 fps | 99.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,413 psi | 43% | 1913 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 50,430 psi | 76% | 3091 fps | 99.1% |
| IMR 7828 SSC | <<locked>> | 80% | 46,383 psi | 70% | 3094 fps | 98.8% |
| IMR 7977 Enduron | <<locked>> | 90% | 56,173 psi | 84% | 3156 fps | 95.5% |
| IMR 8133 Enduron | <<locked>> | 84% | 35,085 psi | 53% | 2835 fps | 95.7% |
| Lovex S071 | <<locked>> | 80% | 41,524 psi | 62% | 2890 fps | 99.9% |
| Norma 217 | <<locked>> | 80% | 30,850 psi | 46% | 2726 fps | 96.1% |
| Norma MRP | <<locked>> | 80% | 51,837 psi | 78% | 3192 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 47,036 psi | 71% | 3110 fps | 99.2% |
| Ramshot Magnum | <<locked>> | 80% | 42,612 psi | 64% | 2969 fps | 99.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,269 psi | 44% | 1962 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 40,103 psi | 60% | 3012 fps | 99.7% |
| ReloadSwiss RS 80 | <<locked>> | 82% | 39,958 psi | 60% | 2963 fps | 96.2% |
| Rottweil R 904 | <<locked>> | 80% | 52,692 psi | 79% | 3140 fps | 99.6% |
| Rottweil R 905 | <<locked>> | 80% | 51,822 psi | 78% | 3150 fps | 99.9% |
| SNPE Vectan SP 13 | <<locked>> | 96% | 46,151 psi | 69% | 3035 fps | 95.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 51,474 psi | 77% | 3143 fps | 99.9% |
| Somchem S361 | <<locked>> | 80% | 53,954 psi | 81% | 3120 fps | 99.4% |
| Somchem S385 | <<locked>> | 80% | 52,098 psi | 78% | 3114 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 45,716 psi | 69% | 2982 fps | 99.6% |
| Vihtavuori N170 | <<locked>> | 86% | 48,414 psi | 73% | 3054 fps | 95.2% |
| Vihtavuori N555 | <<locked>> | 80% | 51,880 psi | 78% | 3120 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 51,227 psi | 77% | 3192 fps | 99.2% |
| Vihtavuori N565 | <<locked>> | 80% | 42,830 psi | 64% | 2992 fps | 97.8% |
| Vihtavuori N568 | <<locked>> | 82% | 40,814 psi | 61% | 2979 fps | 95.8% |
| Vihtavuori N570 | 93.7 gr | 86% | 45,107 psi | 68% | 3110 fps | 95.2% |
| Winchester StaBALL HD | <<locked>> | 80% | 46,920 psi | 70% | 3114 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 48,283 psi | 72% | 3045 fps | 99.7% |
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 | 139gr | Reichenberg HDB Universal. ADI AR 2218 delivers the highest muzzle velocity at 3,435 fps; across all powders the maximum-charge window runs from 2,133 fps to 3,435 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 139.0 gr projectile in 0.284" calls for a 1:11.0 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-33 rank at the top here: for 7.21 Firebird with the .284 | 139gr | Reichenberg HDB Universal 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.