Load Specifications
Load data in caliber 7.21 Firebird with .284 | 125gr | Norma Bondstrike bullet and 57 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon Retumbo, 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.
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Max Load - Barrel Length: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 88% | 59,030 psi | 88% | 3330 fps | 100% |
| Accurate MAGPRO | <<locked>> | 86% | 58,233 psi | 87% | 3445 fps | 99.2% |
| ADI AR 2209 | <<locked>> | 86% | 59,944 psi | 90% | 3428 fps | 100% |
| ADI AR 2213 | <<locked>> | 88% | 58,755 psi | 88% | 3445 fps | 99.7% |
| ADI AR 2217 | <<locked>> | 96% | 57,957 psi | 87% | 3415 fps | 99.9% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 59,205 psi | 89% | 3543 fps | 98.5% |
| ADI AR 2225 | <<locked>> | 98% | 57,188 psi | 86% | 3435 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 82% | 59,915 psi | 90% | 3419 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 59,466 psi | 89% | 3415 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 88% | 59,190 psi | 89% | 3438 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 88% | 57,174 psi | 86% | 3337 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 92% | 57,957 psi | 87% | 3412 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 84% | 58,262 psi | 87% | 3428 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 96% | 56,811 psi | 85% | 3438 fps | 97.8% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 56,884 psi | 85% | 3422 fps | 97.3% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 59,205 psi | 89% | 3392 fps | 98.3% |
| Bofors RP15 | <<locked>> | 90% | 58,537 psi | 88% | 3425 fps | 100% |
| Bofors RP30 | <<locked>> | 94% | 57,856 psi | 87% | 3428 fps | 99.9% |
| Bofors RP5 | <<locked>> | 88% | 59,190 psi | 89% | 3438 fps | 100% |
| Hodgdon H1000 | <<locked>> | 94% | 59,480 psi | 89% | 3438 fps | 100% |
| Hodgdon H4831 | <<locked>> | 86% | 57,595 psi | 86% | 3369 fps | 99.3% |
| Hodgdon H4831 SC | <<locked>> | 86% | 56,449 psi | 85% | 3350 fps | 99.2% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 59,901 psi | 90% | 3323 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 92% | 57,116 psi | 86% | 3507 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,739 psi | 57% | 2231 fps | 100% |
| IMR 4350 | <<locked>> | 82% | 57,928 psi | 87% | 3337 fps | 100% |
| IMR 4831 | <<locked>> | 82% | 58,842 psi | 88% | 3340 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 86% | 57,624 psi | 86% | 3346 fps | 99.4% |
| IMR 7828 SSC | <<locked>> | 88% | 57,130 psi | 86% | 3425 fps | 99.6% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 56,159 psi | 84% | 3409 fps | 99.7% |
| Lovex S070 | <<locked>> | 82% | 60,350 psi | 90% | 3373 fps | 100% |
| Lovex S071 | <<locked>> | 92% | 56,913 psi | 85% | 3297 fps | 100% |
| Norma 204 | <<locked>> | 82% | 59,683 psi | 89% | 3406 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 57,609 psi | 86% | 3435 fps | 100% |
| Norma MRP | <<locked>> | 86% | 59,480 psi | 89% | 3455 fps | 100% |
| Ramshot Grand | <<locked>> | 88% | 58,668 psi | 88% | 3451 fps | 99.9% |
| Ramshot Hunter | <<locked>> | 82% | 59,698 psi | 89% | 3396 fps | 100% |
| Ramshot Magnum | <<locked>> | 90% | 57,319 psi | 86% | 3366 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,580 psi | 58% | 2280 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 58,639 psi | 88% | 3491 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 94% | 57,972 psi | 87% | 3448 fps | 99.3% |
| Rottweil R 904 | <<locked>> | 86% | 60,205 psi | 90% | 3396 fps | 99.8% |
| Rottweil R 905 | <<locked>> | 86% | 59,277 psi | 89% | 3409 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 60,350 psi | 90% | 3373 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 58,871 psi | 88% | 3402 fps | 100% |
| Somchem S361 | <<locked>> | 84% | 58,073 psi | 87% | 3314 fps | 99.4% |
| Somchem S365 | <<locked>> | 82% | 58,436 psi | 88% | 3333 fps | 100% |
| Somchem S385 | <<locked>> | 86% | 59,683 psi | 89% | 3369 fps | 100% |
| Vihtavuori N165 | <<locked>> | 90% | 59,828 psi | 90% | 3353 fps | 100% |
| Vihtavuori N170 | <<locked>> | 94% | 59,379 psi | 89% | 3373 fps | 96.8% |
| Vihtavuori N555 | <<locked>> | 86% | 58,827 psi | 88% | 3366 fps | 100% |
| Vihtavuori N560 | <<locked>> | 86% | 58,726 psi | 88% | 3458 fps | 99.5% |
| Vihtavuori N565 | <<locked>> | 92% | 60,147 psi | 90% | 3445 fps | 99.7% |
| Vihtavuori N568 | <<locked>> | 94% | 58,175 psi | 87% | 3455 fps | 99% |
| Vihtavuori N570 | <<locked>> | 96% | 59,582 psi | 89% | 3524 fps | 97.9% |
| Winchester StaBALL HD | <<locked>> | 88% | 57,972 psi | 87% | 3432 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 59,814 psi | 90% | 3369 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% | 44,831 psi | 67% | 3081 fps | 99.8% |
| Accurate MAGPRO | <<locked>> | 80% | 46,818 psi | 70% | 3222 fps | 97% |
| ADI AR 2209 | <<locked>> | 80% | 48,907 psi | 73% | 3232 fps | 99.2% |
| ADI AR 2213 | <<locked>> | 80% | 44,077 psi | 66% | 3159 fps | 97.4% |
| ADI AR 2217 | <<locked>> | 84% | 37,739 psi | 57% | 2992 fps | 95.7% |
| ADI AR 2218 | <<locked>> | 94% | 47,065 psi | 71% | 3287 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 80% | 30,269 psi | 45% | 2808 fps | 95.3% |
| Alliant Reloder-16 | <<locked>> | 80% | 55,927 psi | 84% | 3356 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 48,718 psi | 73% | 3222 fps | 99.2% |
| Alliant Reloder-22 | <<locked>> | 80% | 44,889 psi | 67% | 3166 fps | 98.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 43,613 psi | 65% | 3104 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 37,884 psi | 57% | 3025 fps | 99.5% |
| Alliant Reloder-26 | <<locked>> | 80% | 50,024 psi | 75% | 3291 fps | 100% |
| Alliant Reloder-33 | 104.4 gr | 92% | 48,559 psi | 73% | 3278 fps | 95.7% |
| Alliant Reloder-50 | <<locked>> | 96% | 48,602 psi | 73% | 3261 fps | 95.1% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 45,426 psi | 68% | 3123 fps | 95% |
| Bofors RP15 | <<locked>> | 80% | 41,756 psi | 63% | 3091 fps | 97.7% |
| Bofors RP30 | <<locked>> | 82% | 37,956 psi | 57% | 3012 fps | 95.9% |
| Bofors RP5 | <<locked>> | 80% | 44,889 psi | 67% | 3166 fps | 98.6% |
| Hodgdon H1000 | <<locked>> | 80% | 35,723 psi | 54% | 2940 fps | 95.5% |
| Hodgdon H4831 | <<locked>> | 80% | 46,731 psi | 70% | 3163 fps | 97.5% |
| Hodgdon H4831 SC | <<locked>> | 80% | 45,818 psi | 69% | 3143 fps | 97.2% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 52,591 psi | 79% | 3212 fps | 100% |
| Hodgdon Retumbo | 84.2 gr | 80% | 36,985 psi | 55% | 3064 fps | 97.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,253 psi | 42% | 2005 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 54,476 psi | 82% | 3278 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 55,230 psi | 83% | 3284 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 47,543 psi | 71% | 3153 fps | 97.8% |
| IMR 7828 SSC | <<locked>> | 80% | 42,888 psi | 64% | 3140 fps | 97.1% |
| IMR 8133 Enduron | <<locked>> | 88% | 36,869 psi | 55% | 2995 fps | 95.2% |
| Lovex S070 | <<locked>> | 80% | 56,550 psi | 85% | 3314 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 38,580 psi | 58% | 2943 fps | 99% |
| Norma 204 | <<locked>> | 80% | 55,637 psi | 83% | 3337 fps | 99.8% |
| Norma 217 | <<locked>> | 84% | 32,329 psi | 48% | 2884 fps | 95.6% |
| Norma MRP | <<locked>> | 80% | 48,022 psi | 72% | 3251 fps | 99.8% |
| Ramshot Grand | <<locked>> | 80% | 43,134 psi | 65% | 3150 fps | 97.5% |
| Ramshot Hunter | <<locked>> | 80% | 55,724 psi | 84% | 3333 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 39,088 psi | 59% | 3012 fps | 98% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,066 psi | 44% | 2054 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 36,564 psi | 55% | 3035 fps | 98.3% |
| ReloadSwiss RS 80 | <<locked>> | 86% | 42,424 psi | 64% | 3133 fps | 95.9% |
| Rottweil R 904 | <<locked>> | 80% | 49,429 psi | 74% | 3199 fps | 98.6% |
| Rottweil R 905 | <<locked>> | 80% | 48,414 psi | 73% | 3212 fps | 99.2% |
| Shooters World SW4350 | <<locked>> | 80% | 56,550 psi | 85% | 3314 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 48,066 psi | 72% | 3205 fps | 99.2% |
| Somchem S361 | <<locked>> | 80% | 50,792 psi | 76% | 3186 fps | 98.4% |
| Somchem S365 | <<locked>> | 80% | 54,708 psi | 82% | 3278 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 48,805 psi | 73% | 3182 fps | 99.7% |
| Vihtavuori N165 | <<locked>> | 80% | 42,670 psi | 64% | 3038 fps | 98.6% |
| Vihtavuori N170 | <<locked>> | 92% | 55,564 psi | 83% | 3304 fps | 95.9% |
| Vihtavuori N555 | <<locked>> | 80% | 48,298 psi | 72% | 3192 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 47,572 psi | 71% | 3245 fps | 97.8% |
| Vihtavuori N565 | <<locked>> | 80% | 39,566 psi | 59% | 3028 fps | 95.6% |
| Vihtavuori N568 | <<locked>> | 86% | 43,381 psi | 65% | 3156 fps | 95.6% |
| Vihtavuori N570 | 100.5 gr | 92% | 51,532 psi | 77% | 3369 fps | 96% |
| Winchester StaBALL HD | <<locked>> | 80% | 42,380 psi | 64% | 3163 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 45,092 psi | 68% | 3100 fps | 98.6% |
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 57 powders for 7.21 Firebird loaded with the .284 | 125gr | Norma Bondstrike. ADI AR 2218 delivers the highest muzzle velocity at 3,543 fps; across all powders the maximum-charge window runs from 2,231 fps to 3,543 fps. ADI AR 2218 gives the best case fill at 100 %, and 57 of the 57 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 125.0 gr projectile in 0.284" calls for a 1:11.5 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, Vihtavuori N570, Alliant Reloder-33 rank at the top here: for 7.21 Firebird with the .284 | 125gr | Norma Bondstrike 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.