Load Specifications
Load data in caliber 7.21 Firebird with .284 | 120gr | Hornady V-MAX 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% | 58,015 psi | 87% | 3363 fps | 100% |
| Accurate MAGPRO | <<locked>> | 86% | 57,130 psi | 86% | 3471 fps | 98.8% |
| ADI AR 2209 | <<locked>> | 86% | 59,030 psi | 88% | 3465 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 88% | 57,725 psi | 87% | 3478 fps | 99.5% |
| ADI AR 2217 | <<locked>> | 96% | 56,724 psi | 85% | 3442 fps | 99.7% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 57,957 psi | 87% | 3563 fps | 98% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 60,147 psi | 90% | 3530 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 82% | 58,885 psi | 88% | 3455 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 58,566 psi | 88% | 3451 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 88% | 58,189 psi | 87% | 3471 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 90% | 59,944 psi | 90% | 3428 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 92% | 56,782 psi | 85% | 3448 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 84% | 57,072 psi | 86% | 3461 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 60,017 psi | 90% | 3543 fps | 98.1% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 55,506 psi | 83% | 3442 fps | 96.7% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 58,218 psi | 87% | 3419 fps | 97.9% |
| Bofors RP15 | <<locked>> | 90% | 57,348 psi | 86% | 3455 fps | 99.9% |
| Bofors RP30 | <<locked>> | 94% | 56,666 psi | 85% | 3458 fps | 99.7% |
| Bofors RP5 | <<locked>> | 88% | 58,189 psi | 87% | 3471 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 94% | 58,407 psi | 88% | 3471 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 86% | 56,478 psi | 85% | 3399 fps | 99% |
| Hodgdon H4831 SC | <<locked>> | 88% | 59,495 psi | 89% | 3448 fps | 99.3% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 59,074 psi | 89% | 3363 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 94% | 60,031 psi | 90% | 3606 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,666 psi | 56% | 2274 fps | 100% |
| IMR 4350 | <<locked>> | 82% | 57,203 psi | 86% | 3376 fps | 100% |
| IMR 4831 | <<locked>> | 82% | 58,059 psi | 87% | 3379 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 86% | 56,826 psi | 85% | 3379 fps | 99.1% |
| IMR 7828 SSC | <<locked>> | 90% | 60,118 psi | 90% | 3524 fps | 99.7% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 54,868 psi | 82% | 3435 fps | 99.5% |
| Lovex S070 | <<locked>> | 82% | 59,422 psi | 89% | 3412 fps | 100% |
| Lovex S071 | <<locked>> | 94% | 59,727 psi | 90% | 3389 fps | 100% |
| Norma 204 | <<locked>> | 82% | 58,813 psi | 88% | 3442 fps | 99.9% |
| Norma 217ᴾ | <<locked>> | 100% | 56,159 psi | 84% | 3461 fps | 100% |
| Norma MRP | <<locked>> | 86% | 58,392 psi | 88% | 3488 fps | 100% |
| Norma URP | <<locked>> | 82% | 59,553 psi | 89% | 3428 fps | 100% |
| Ramshot Grand | <<locked>> | 88% | 57,435 psi | 86% | 3478 fps | 99.7% |
| Ramshot Hunter | <<locked>> | 82% | 58,856 psi | 88% | 3435 fps | 100% |
| Ramshot Magnum | <<locked>> | 90% | 56,115 psi | 84% | 3392 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,493 psi | 58% | 2323 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 57,334 psi | 86% | 3524 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 94% | 56,724 psi | 85% | 3474 fps | 99% |
| Rottweil R 904 | <<locked>> | 86% | 59,393 psi | 89% | 3428 fps | 99.6% |
| Rottweil R 905 | <<locked>> | 86% | 58,363 psi | 87% | 3445 fps | 99.9% |
| Shooters World SW4350 | <<locked>> | 82% | 59,422 psi | 89% | 3412 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 59,828 psi | 90% | 3356 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 57,972 psi | 87% | 3438 fps | 99.9% |
| Somchem S361 | <<locked>> | 84% | 57,217 psi | 86% | 3346 fps | 99.1% |
| Somchem S365 | <<locked>> | 82% | 57,522 psi | 86% | 3376 fps | 100% |
| Somchem S385 | <<locked>> | 86% | 58,610 psi | 88% | 3402 fps | 100% |
| Vihtavuori N165 | <<locked>> | 90% | 58,842 psi | 88% | 3386 fps | 100% |
| Vihtavuori N170 | <<locked>> | 94% | 58,407 psi | 88% | 3399 fps | 96.2% |
| Vihtavuori N555 | <<locked>> | 86% | 57,885 psi | 87% | 3406 fps | 100% |
| Vihtavuori N560 | <<locked>> | 86% | 57,682 psi | 86% | 3488 fps | 99.3% |
| Vihtavuori N565 | <<locked>> | 92% | 58,943 psi | 88% | 3474 fps | 99.5% |
| Vihtavuori N568 | <<locked>> | 94% | 56,884 psi | 85% | 3478 fps | 98.6% |
| Vihtavuori N570 | <<locked>> | 96% | 58,363 psi | 87% | 3550 fps | 97.4% |
| Winchester StaBALL HD | <<locked>> | 88% | 56,579 psi | 85% | 3461 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 58,827 psi | 88% | 3402 fps | 99.9% |
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% | 43,976 psi | 66% | 3107 fps | 99.6% |
| Accurate MAGPRO | <<locked>> | 80% | 45,832 psi | 69% | 3245 fps | 96.3% |
| ADI AR 2209 | <<locked>> | 80% | 48,037 psi | 72% | 3261 fps | 98.8% |
| ADI AR 2213 | <<locked>> | 80% | 43,207 psi | 65% | 3182 fps | 96.7% |
| ADI AR 2217 | <<locked>> | 86% | 39,784 psi | 60% | 3087 fps | 96.1% |
| ADI AR 2218 | <<locked>> | 96% | 49,705 psi | 75% | 3392 fps | 95.6% |
| ADI AR 2225 | <<locked>> | 82% | 31,763 psi | 48% | 2900 fps | 95.8% |
| Alliant Reloder-16 | <<locked>> | 80% | 54,984 psi | 82% | 3396 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 47,877 psi | 72% | 3251 fps | 98.8% |
| Alliant Reloder-22 | <<locked>> | 80% | 43,990 psi | 66% | 3192 fps | 98.1% |
| Alliant Reloder-23 | <<locked>> | 80% | 42,743 psi | 64% | 3133 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 37,057 psi | 56% | 3048 fps | 99.1% |
| Alliant Reloder-26 | <<locked>> | 80% | 48,994 psi | 73% | 3320 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 51,372 psi | 77% | 3379 fps | 96.1% |
| Alliant Reloder-50 | <<locked>> | 98% | 51,300 psi | 77% | 3360 fps | 95.5% |
| Baschieri & Pellagri 109 | <<locked>> | 84% | 47,819 psi | 72% | 3219 fps | 95.4% |
| Bofors RP15 | <<locked>> | 80% | 40,944 psi | 61% | 3117 fps | 97.2% |
| Bofors RP30 | <<locked>> | 82% | 37,101 psi | 56% | 3028 fps | 95% |
| Bofors RP5 | <<locked>> | 80% | 43,990 psi | 66% | 3192 fps | 98.1% |
| Hodgdon H1000 | <<locked>> | 82% | 37,695 psi | 56% | 3038 fps | 96% |
| Hodgdon H4831 | <<locked>> | 80% | 45,876 psi | 69% | 3189 fps | 96.9% |
| Hodgdon H4831 SC | <<locked>> | 80% | 44,976 psi | 67% | 3169 fps | 96.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 51,735 psi | 78% | 3251 fps | 100% |
| Hodgdon Retumbo | 84.9 gr | 80% | 36,172 psi | 54% | 3081 fps | 96.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,137 psi | 42% | 2044 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 53,635 psi | 80% | 3314 fps | 99.9% |
| IMR 4831 | <<locked>> | 80% | 54,346 psi | 81% | 3320 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 46,789 psi | 70% | 3182 fps | 97.3% |
| IMR 7828 SSC | <<locked>> | 80% | 41,974 psi | 63% | 3163 fps | 96.4% |
| IMR 8133 Enduron | <<locked>> | 90% | 38,638 psi | 58% | 3081 fps | 95.5% |
| Lovex S070 | <<locked>> | 80% | 55,695 psi | 83% | 3350 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 37,724 psi | 57% | 2963 fps | 98.5% |
| Norma 204 | <<locked>> | 80% | 54,824 psi | 82% | 3373 fps | 99.6% |
| Norma 217 | <<locked>> | 86% | 33,881 psi | 51% | 2972 fps | 95.9% |
| Norma MRP | <<locked>> | 80% | 46,992 psi | 70% | 3274 fps | 99.5% |
| Norma URP | <<locked>> | 80% | 55,738 psi | 84% | 3369 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 42,250 psi | 63% | 3176 fps | 96.9% |
| Ramshot Hunter | <<locked>> | 80% | 54,955 psi | 82% | 3369 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 38,145 psi | 57% | 3028 fps | 97.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,921 psi | 43% | 2093 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 35,665 psi | 53% | 3051 fps | 97.5% |
| ReloadSwiss RS 80 | 98.4 gr | 86% | 41,423 psi | 62% | 3153 fps | 95.1% |
| Rottweil R 904 | <<locked>> | 80% | 48,646 psi | 73% | 3232 fps | 98.2% |
| Rottweil R 905 | <<locked>> | 80% | 47,543 psi | 71% | 3241 fps | 98.9% |
| Shooters World SW4350 | <<locked>> | 80% | 55,695 psi | 83% | 3350 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 56,057 psi | 84% | 3297 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 47,195 psi | 71% | 3238 fps | 98.8% |
| Somchem S361 | <<locked>> | 80% | 49,922 psi | 75% | 3212 fps | 97.9% |
| Somchem S365 | <<locked>> | 80% | 53,722 psi | 81% | 3314 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 47,935 psi | 72% | 3209 fps | 99.4% |
| Vihtavuori N165 | <<locked>> | 80% | 41,887 psi | 63% | 3068 fps | 98.1% |
| Vihtavuori N170 | <<locked>> | 92% | 54,505 psi | 82% | 3330 fps | 95.3% |
| Vihtavuori N555 | <<locked>> | 80% | 47,398 psi | 71% | 3222 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 46,586 psi | 70% | 3268 fps | 97.2% |
| Vihtavuori N565 | <<locked>> | 82% | 41,611 psi | 62% | 3123 fps | 96% |
| Vihtavuori N568 | <<locked>> | 88% | 45,672 psi | 68% | 3251 fps | 96% |
| Vihtavuori N570 | 101.3 gr | 92% | 50,328 psi | 75% | 3389 fps | 95.3% |
| Winchester StaBALL HD | <<locked>> | 80% | 41,365 psi | 62% | 3189 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 44,396 psi | 67% | 3130 fps | 98.2% |
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 | 120gr | Hornady V-MAX. Hodgdon Retumbo delivers the highest muzzle velocity at 3,606 fps; across all powders the maximum-charge window runs from 2,274 fps to 3,606 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 120.0 gr projectile in 0.284" calls for a 1:12.0 twist; slower twists will usually not stabilise this weight. ADI AR 2218, ADI AR 2225, Alliant Reloder-50 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 | 120gr | Hornady V-MAX 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.