Load Specifications
Load data in caliber 7.21 Firebird with .284 | 140gr | Berger VLD Hunting 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, Hodgdon Retumbo 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.
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% | 58,827 psi | 88% | 3182 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 50,937 psi | 76% | 3146 fps | 97% |
| Accurate MAGPRO | <<locked>> | 84% | 58,030 psi | 87% | 3304 fps | 99.6% |
| ADI AR 2209 | <<locked>> | 84% | 59,669 psi | 89% | 3284 fps | 100% |
| ADI AR 2213 | <<locked>> | 86% | 58,639 psi | 88% | 3301 fps | 100% |
| ADI AR 2217 | <<locked>> | 94% | 58,073 psi | 87% | 3278 fps | 100% |
| ADI AR 2218 | <<locked>> | 98% | 59,379 psi | 89% | 3419 fps | 99.3% |
| ADI AR 2225 | <<locked>> | 96% | 57,856 psi | 87% | 3301 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 59,059 psi | 89% | 3268 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 86% | 59,117 psi | 89% | 3294 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 86% | 57,305 psi | 86% | 3189 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 90% | 58,305 psi | 87% | 3274 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 82% | 58,247 psi | 87% | 3281 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 57,188 psi | 86% | 3320 fps | 98.7% |
| Alliant Reloder-50 | <<locked>> | 98% | 57,363 psi | 86% | 3307 fps | 98.3% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 58,697 psi | 88% | 3251 fps | 99% |
| Bofors RP15 | <<locked>> | 88% | 58,479 psi | 88% | 3284 fps | 100% |
| Bofors RP30 | <<locked>> | 92% | 58,030 psi | 87% | 3294 fps | 100% |
| Bofors RP5 | <<locked>> | 86% | 59,117 psi | 89% | 3294 fps | 100% |
| Hodgdon H1000 | <<locked>> | 92% | 59,770 psi | 90% | 3304 fps | 100% |
| Hodgdon H4831 | <<locked>> | 84% | 57,203 psi | 86% | 3225 fps | 99.7% |
| Hodgdon H4831 SC | <<locked>> | 86% | 60,075 psi | 90% | 3274 fps | 99.9% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 59,698 psi | 89% | 3173 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 90% | 57,972 psi | 87% | 3373 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,884 psi | 57% | 2123 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 84% | 57,174 psi | 86% | 3202 fps | 99.8% |
| IMR 7828 SSC | <<locked>> | 86% | 57,130 psi | 86% | 3284 fps | 99.9% |
| IMR 7977 Enduron | <<locked>> | 92% | 59,683 psi | 89% | 3205 fps | 96.3% |
| IMR 8133 Enduron | <<locked>> | 98% | 56,681 psi | 85% | 3281 fps | 100% |
| Lovex S071 | <<locked>> | 90% | 57,087 psi | 86% | 3159 fps | 100% |
| Norma 217 | <<locked>> | 98% | 58,305 psi | 87% | 3307 fps | 100% |
| Norma MRP | <<locked>> | 84% | 59,393 psi | 89% | 3307 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 58,755 psi | 88% | 3310 fps | 100% |
| Ramshot Magnum | <<locked>> | 88% | 57,261 psi | 86% | 3225 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,943 psi | 58% | 2172 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 59,263 psi | 89% | 3356 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 58,262 psi | 87% | 3320 fps | 99.8% |
| Rottweil R 904 | <<locked>> | 84% | 59,727 psi | 90% | 3248 fps | 100% |
| Rottweil R 905 | <<locked>> | 84% | 59,103 psi | 89% | 3261 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 52,881 psi | 79% | 3159 fps | 97.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 58,726 psi | 88% | 3258 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 57,493 psi | 86% | 3173 fps | 99.7% |
| Somchem S385 | <<locked>> | 84% | 59,364 psi | 89% | 3225 fps | 100% |
| Vihtavuori N165 | <<locked>> | 88% | 59,567 psi | 89% | 3209 fps | 100% |
| Vihtavuori N170 | <<locked>> | 92% | 59,248 psi | 89% | 3245 fps | 97.7% |
| Vihtavuori N555 | <<locked>> | 84% | 58,842 psi | 88% | 3222 fps | 100% |
| Vihtavuori N560 | <<locked>> | 84% | 58,624 psi | 88% | 3314 fps | 99.9% |
| Vihtavuori N565 | <<locked>> | 90% | 60,234 psi | 90% | 3310 fps | 100% |
| Vihtavuori N568 | <<locked>> | 92% | 58,436 psi | 88% | 3323 fps | 99.6% |
| Vihtavuori N570 | <<locked>> | 94% | 60,017 psi | 90% | 3396 fps | 98.8% |
| Winchester StaBALL HD | <<locked>> | 86% | 58,566 psi | 88% | 3287 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 86% | 59,263 psi | 89% | 3222 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% | 48,037 psi | 72% | 3012 fps | 100% |
| Accurate 8700 | <<locked>> | 98% | 47,311 psi | 71% | 3074 fps | 96% |
| Accurate MAGPRO | <<locked>> | 80% | 50,328 psi | 75% | 3163 fps | 98.7% |
| ADI AR 2209 | <<locked>> | 80% | 52,011 psi | 78% | 3156 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 80% | 47,427 psi | 71% | 3100 fps | 99% |
| ADI AR 2217 | <<locked>> | 80% | 35,389 psi | 53% | 2812 fps | 96.1% |
| ADI AR 2218 | 99.3 gr | 90% | 43,772 psi | 66% | 3097 fps | 95.3% |
| ADI AR 2225 | <<locked>> | 80% | 32,706 psi | 49% | 2779 fps | 98% |
| Alliant Reloder-19 | <<locked>> | 80% | 51,866 psi | 78% | 3146 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 80% | 48,196 psi | 72% | 3100 fps | 99.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 46,891 psi | 70% | 3025 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 41,002 psi | 61% | 2966 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 80% | 54,085 psi | 81% | 3215 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 88% | 45,440 psi | 68% | 3087 fps | 95.9% |
| Alliant Reloder-50 | <<locked>> | 92% | 45,730 psi | 69% | 3081 fps | 95.4% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 45,121 psi | 68% | 2995 fps | 96.1% |
| Bofors RP15 | <<locked>> | 80% | 44,860 psi | 67% | 3031 fps | 99.2% |
| Bofors RP30 | <<locked>> | 80% | 38,377 psi | 58% | 2897 fps | 97.2% |
| Bofors RP5 | <<locked>> | 80% | 48,196 psi | 72% | 3100 fps | 99.7% |
| Hodgdon H1000 | <<locked>> | 80% | 38,551 psi | 58% | 2900 fps | 97.9% |
| Hodgdon H4831 | <<locked>> | 80% | 49,719 psi | 75% | 3094 fps | 98.9% |
| Hodgdon H4831 SC | <<locked>> | 80% | 48,892 psi | 73% | 3077 fps | 98.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 55,912 psi | 84% | 3120 fps | 100% |
| Hodgdon Retumbo | 83.3 gr | 80% | 40,103 psi | 60% | 3025 fps | 99.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,427 psi | 43% | 1906 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 50,183 psi | 75% | 3077 fps | 99.1% |
| IMR 7828 SSC | <<locked>> | 80% | 46,282 psi | 69% | 3084 fps | 98.8% |
| IMR 7977 Enduron | <<locked>> | 90% | 55,840 psi | 84% | 3143 fps | 95.5% |
| IMR 8133 Enduron | <<locked>> | 84% | 35,027 psi | 53% | 2825 fps | 95.7% |
| Lovex S071 | <<locked>> | 80% | 41,379 psi | 62% | 2877 fps | 99.9% |
| Norma 217 | <<locked>> | 80% | 30,632 psi | 46% | 2717 fps | 96% |
| Norma MRP | <<locked>> | 80% | 51,576 psi | 77% | 3179 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 46,934 psi | 70% | 3100 fps | 99.2% |
| Ramshot Magnum | <<locked>> | 80% | 42,395 psi | 64% | 2959 fps | 99.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,298 psi | 44% | 1952 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 39,871 psi | 60% | 2999 fps | 99.7% |
| ReloadSwiss RS 80 | <<locked>> | 82% | 39,784 psi | 60% | 2953 fps | 96.2% |
| Rottweil R 904 | <<locked>> | 80% | 52,446 psi | 79% | 3123 fps | 99.6% |
| Rottweil R 905 | <<locked>> | 80% | 51,706 psi | 78% | 3140 fps | 99.9% |
| SNPE Vectan SP 13 | <<locked>> | 96% | 45,876 psi | 69% | 3022 fps | 95.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 51,358 psi | 77% | 3133 fps | 99.9% |
| Somchem S361 | <<locked>> | 80% | 53,737 psi | 81% | 3110 fps | 99.4% |
| Somchem S385 | <<locked>> | 80% | 51,996 psi | 78% | 3107 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 45,643 psi | 68% | 2972 fps | 99.6% |
| Vihtavuori N170 | <<locked>> | 86% | 48,254 psi | 72% | 3045 fps | 95.2% |
| Vihtavuori N555 | <<locked>> | 80% | 51,750 psi | 78% | 3110 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 50,966 psi | 76% | 3179 fps | 99.2% |
| Vihtavuori N565 | <<locked>> | 80% | 42,743 psi | 64% | 2982 fps | 97.8% |
| Vihtavuori N568 | <<locked>> | 82% | 40,611 psi | 61% | 2966 fps | 95.8% |
| Vihtavuori N570 | 93 gr | 86% | 44,875 psi | 67% | 3100 fps | 95.2% |
| Winchester StaBALL HD | <<locked>> | 80% | 46,673 psi | 70% | 3097 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 48,225 psi | 72% | 3035 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 | 140gr | Berger VLD Hunting. ADI AR 2218 delivers the highest muzzle velocity at 3,419 fps; across all powders the maximum-charge window runs from 2,123 fps to 3,419 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 140.0 gr projectile in 0.284" calls for a 1:10.5 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, Hodgdon Retumbo, Vihtavuori N570 rank at the top here: for 7.21 Firebird with the .284 | 140gr | Berger VLD 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.