Load Specifications
Load data in caliber 7.21 Firebird with .284 | 127gr | Hasler Hunting bullet and 59 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon Retumbo, ReloadSwiss RS 80 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>> | 88% | 57,580 psi | 86% | 3291 fps | 100% |
| Accurate MAGPRO | <<locked>> | 86% | 57,087 psi | 86% | 3409 fps | 99.1% |
| ADI AR 2209 | <<locked>> | 86% | 59,117 psi | 89% | 3399 fps | 100% |
| ADI AR 2213 | <<locked>> | 88% | 57,725 psi | 87% | 3412 fps | 99.7% |
| ADI AR 2217 | <<locked>> | 96% | 56,942 psi | 85% | 3383 fps | 99.9% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 58,030 psi | 87% | 3507 fps | 98.4% |
| ADI AR 2225 | <<locked>> | 98% | 56,101 psi | 84% | 3402 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 82% | 59,059 psi | 89% | 3386 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 58,639 psi | 88% | 3386 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 88% | 58,059 psi | 87% | 3402 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 90% | 60,002 psi | 90% | 3360 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 92% | 56,840 psi | 85% | 3379 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 84% | 56,927 psi | 85% | 3392 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 60,031 psi | 90% | 3481 fps | 98.4% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 55,230 psi | 83% | 3379 fps | 97.1% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 58,436 psi | 88% | 3363 fps | 98.3% |
| Bofors RP15 | <<locked>> | 90% | 57,421 psi | 86% | 3392 fps | 100% |
| Bofors RP30 | <<locked>> | 94% | 56,652 psi | 85% | 3392 fps | 99.8% |
| Bofors RP5 | <<locked>> | 88% | 58,059 psi | 87% | 3402 fps | 100% |
| Hodgdon H1000 | <<locked>> | 94% | 58,450 psi | 88% | 3406 fps | 100% |
| Hodgdon H4831 | <<locked>> | 86% | 56,579 psi | 85% | 3337 fps | 99.3% |
| Hodgdon H4831 SC | <<locked>> | 88% | 59,466 psi | 89% | 3386 fps | 99.6% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 58,972 psi | 88% | 3294 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 94% | 60,350 psi | 90% | 3540 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,637 psi | 56% | 2215 fps | 100% |
| IMR 4350 | <<locked>> | 82% | 57,159 psi | 86% | 3307 fps | 100% |
| IMR 4831 | <<locked>> | 82% | 57,812 psi | 87% | 3307 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 86% | 56,884 psi | 85% | 3314 fps | 99.4% |
| IMR 7828 SSC | <<locked>> | 90% | 60,249 psi | 90% | 3458 fps | 99.9% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 54,911 psi | 82% | 3373 fps | 99.7% |
| Lovex S070 | <<locked>> | 82% | 59,364 psi | 89% | 3343 fps | 100% |
| Lovex S071 | <<locked>> | 94% | 59,524 psi | 89% | 3320 fps | 100% |
| Norma 204 | <<locked>> | 82% | 58,871 psi | 88% | 3376 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 56,057 psi | 84% | 3396 fps | 100% |
| Norma MRP | <<locked>> | 86% | 58,479 psi | 88% | 3422 fps | 100% |
| Norma URP | <<locked>> | 82% | 59,611 psi | 89% | 3360 fps | 100% |
| Ramshot Grand | <<locked>> | 88% | 57,551 psi | 86% | 3412 fps | 99.8% |
| Ramshot Hunter | <<locked>> | 82% | 58,827 psi | 88% | 3366 fps | 100% |
| Ramshot Magnum | <<locked>> | 90% | 56,144 psi | 84% | 3330 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,450 psi | 58% | 2260 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 57,450 psi | 86% | 3458 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 94% | 56,695 psi | 85% | 3412 fps | 99.3% |
| Rottweil R 904 | <<locked>> | 86% | 59,437 psi | 89% | 3363 fps | 99.8% |
| Rottweil R 905 | <<locked>> | 86% | 58,349 psi | 87% | 3376 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 59,364 psi | 89% | 3343 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 59,872 psi | 90% | 3291 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 57,957 psi | 87% | 3369 fps | 100% |
| Somchem S361 | <<locked>> | 84% | 57,261 psi | 86% | 3284 fps | 99.3% |
| Somchem S365 | <<locked>> | 82% | 57,348 psi | 86% | 3301 fps | 100% |
| Somchem S385 | <<locked>> | 86% | 58,537 psi | 88% | 3337 fps | 100% |
| Vihtavuori N165 | <<locked>> | 90% | 58,740 psi | 88% | 3320 fps | 100% |
| Vihtavuori N170 | <<locked>> | 94% | 58,233 psi | 87% | 3337 fps | 96.6% |
| Vihtavuori N555 | <<locked>> | 86% | 57,624 psi | 86% | 3333 fps | 100% |
| Vihtavuori N560 | <<locked>> | 86% | 57,856 psi | 87% | 3425 fps | 99.5% |
| Vihtavuori N565 | <<locked>> | 92% | 58,856 psi | 88% | 3409 fps | 99.7% |
| Vihtavuori N568 | <<locked>> | 94% | 57,000 psi | 85% | 3415 fps | 98.9% |
| Vihtavuori N570 | <<locked>> | 96% | 58,450 psi | 88% | 3488 fps | 97.8% |
| Winchester StaBALL HD | <<locked>> | 88% | 56,594 psi | 85% | 3392 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 58,740 psi | 88% | 3333 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% | 43,526 psi | 65% | 3041 fps | 99.8% |
| Accurate MAGPRO | <<locked>> | 80% | 45,774 psi | 69% | 3186 fps | 96.8% |
| ADI AR 2209 | <<locked>> | 80% | 48,051 psi | 72% | 3199 fps | 99.1% |
| ADI AR 2213 | <<locked>> | 80% | 43,192 psi | 65% | 3123 fps | 97.2% |
| ADI AR 2217 | <<locked>> | 84% | 36,811 psi | 55% | 2956 fps | 95.5% |
| ADI AR 2218 | <<locked>> | 96% | 49,705 psi | 75% | 3337 fps | 96.3% |
| ADI AR 2225 | <<locked>> | 82% | 31,444 psi | 47% | 2838 fps | 96.2% |
| Alliant Reloder-16 | <<locked>> | 80% | 55,042 psi | 83% | 3327 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 47,819 psi | 72% | 3186 fps | 99.1% |
| Alliant Reloder-22 | <<locked>> | 80% | 43,874 psi | 66% | 3127 fps | 98.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 42,525 psi | 64% | 3064 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 36,869 psi | 55% | 2982 fps | 99.3% |
| Alliant Reloder-26 | <<locked>> | 80% | 48,834 psi | 73% | 3251 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 47,369 psi | 71% | 3238 fps | 95.4% |
| Alliant Reloder-50 | <<locked>> | 98% | 51,111 psi | 77% | 3297 fps | 96% |
| Baschieri & Pellagri 109 | <<locked>> | 84% | 47,776 psi | 72% | 3159 fps | 95.9% |
| Bofors RP15 | <<locked>> | 80% | 40,727 psi | 61% | 3051 fps | 97.5% |
| Bofors RP30 | <<locked>> | 82% | 36,840 psi | 55% | 2966 fps | 95.5% |
| Bofors RP5 | <<locked>> | 80% | 43,874 psi | 66% | 3127 fps | 98.5% |
| Hodgdon H1000 | <<locked>> | 80% | 34,780 psi | 52% | 2900 fps | 95.2% |
| Hodgdon H4831 | <<locked>> | 80% | 45,861 psi | 69% | 3127 fps | 97.3% |
| Hodgdon H4831 SC | <<locked>> | 80% | 44,918 psi | 67% | 3110 fps | 97.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 51,619 psi | 77% | 3182 fps | 100% |
| Hodgdon Retumbo | 83.7 gr | 80% | 35,955 psi | 54% | 3022 fps | 96.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,079 psi | 42% | 1988 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 53,650 psi | 80% | 3251 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 54,201 psi | 81% | 3251 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 46,717 psi | 70% | 3120 fps | 97.7% |
| IMR 7828 SSC | <<locked>> | 80% | 41,945 psi | 63% | 3100 fps | 96.9% |
| IMR 8133 Enduron | <<locked>> | 90% | 38,392 psi | 58% | 3018 fps | 96% |
| Lovex S070 | <<locked>> | 80% | 55,550 psi | 83% | 3278 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 37,275 psi | 56% | 2897 fps | 98.8% |
| Norma 204 | <<locked>> | 80% | 54,766 psi | 82% | 3304 fps | 99.8% |
| Norma 217 | <<locked>> | 84% | 31,111 psi | 47% | 2831 fps | 95% |
| Norma MRP | <<locked>> | 80% | 46,789 psi | 70% | 3209 fps | 99.7% |
| Norma URP | <<locked>> | 80% | 55,680 psi | 83% | 3301 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 42,119 psi | 63% | 3114 fps | 97.4% |
| Ramshot Hunter | <<locked>> | 80% | 54,853 psi | 82% | 3304 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 37,855 psi | 57% | 2963 fps | 97.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,863 psi | 43% | 2037 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 35,476 psi | 53% | 2992 fps | 98% |
| ReloadSwiss RS 80 | 97 gr | 86% | 41,133 psi | 62% | 3091 fps | 95.5% |
| Rottweil R 904 | <<locked>> | 80% | 48,588 psi | 73% | 3166 fps | 98.5% |
| Rottweil R 905 | <<locked>> | 80% | 47,398 psi | 71% | 3176 fps | 99.1% |
| Shooters World SW4350 | <<locked>> | 80% | 55,550 psi | 83% | 3278 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 55,956 psi | 84% | 3228 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 47,079 psi | 71% | 3173 fps | 99.1% |
| Somchem S361 | <<locked>> | 80% | 49,777 psi | 75% | 3150 fps | 98.3% |
| Somchem S365 | <<locked>> | 80% | 53,635 psi | 80% | 3245 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 47,732 psi | 72% | 3146 fps | 99.6% |
| Vihtavuori N165 | <<locked>> | 80% | 41,698 psi | 63% | 3002 fps | 98.5% |
| Vihtavuori N170 | <<locked>> | 92% | 54,418 psi | 82% | 3268 fps | 95.8% |
| Vihtavuori N555 | <<locked>> | 80% | 47,065 psi | 71% | 3153 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 46,427 psi | 70% | 3202 fps | 97.6% |
| Vihtavuori N565 | <<locked>> | 80% | 38,392 psi | 58% | 2986 fps | 95.3% |
| Vihtavuori N568 | <<locked>> | 86% | 42,148 psi | 63% | 3110 fps | 95.2% |
| Vihtavuori N570 | 99.9 gr | 92% | 50,343 psi | 75% | 3330 fps | 95.8% |
| Winchester StaBALL HD | <<locked>> | 80% | 41,118 psi | 62% | 3120 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 44,121 psi | 66% | 3064 fps | 98.5% |
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 59 powders for 7.21 Firebird loaded with the .284 | 127gr | Hasler Hunting. Hodgdon Retumbo delivers the highest muzzle velocity at 3,540 fps; across all powders the maximum-charge window runs from 2,215 fps to 3,540 fps. ADI AR 2218 gives the best case fill at 100 %, and 59 of the 59 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (460 MPa), the top charges use 56–90 %, leaving at least 10 % headroom. The 127.0 gr projectile in 0.284" calls for a 1:10.5 twist; slower twists will usually not stabilise this weight. ADI AR 2218, Alliant Reloder-50, Hodgdon TrailBoss 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, ReloadSwiss RS 80, Vihtavuori N570 rank at the top here: for 7.21 Firebird with the .284 | 127gr | Hasler Hunting 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.