Load Specifications
Load data in caliber 7.21 Firebird with .284 | 132gr | CutEdge Maximus bullet and 55 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% | 58,943 psi | 88% | 3268 fps | 100% |
| Accurate MAGPRO | <<locked>> | 86% | 58,363 psi | 87% | 3386 fps | 99.4% |
| ADI AR 2209 | <<locked>> | 86% | 60,278 psi | 90% | 3373 fps | 100% |
| ADI AR 2213 | <<locked>> | 88% | 59,190 psi | 89% | 3389 fps | 99.9% |
| ADI AR 2217 | <<locked>> | 96% | 58,363 psi | 87% | 3360 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 59,640 psi | 89% | 3497 fps | 99% |
| ADI AR 2225 | <<locked>> | 98% | 57,667 psi | 86% | 3379 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 82% | 60,350 psi | 90% | 3356 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 59,727 psi | 90% | 3356 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 88% | 59,480 psi | 89% | 3376 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 88% | 57,377 psi | 86% | 3271 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 92% | 58,233 psi | 87% | 3353 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 84% | 58,508 psi | 88% | 3366 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 96% | 57,000 psi | 85% | 3386 fps | 98.2% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 56,927 psi | 85% | 3369 fps | 97.8% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 59,567 psi | 89% | 3337 fps | 98.7% |
| Bofors RP15 | <<locked>> | 90% | 58,813 psi | 88% | 3366 fps | 100% |
| Bofors RP30 | <<locked>> | 94% | 58,015 psi | 87% | 3369 fps | 100% |
| Bofors RP5 | <<locked>> | 88% | 59,480 psi | 89% | 3376 fps | 100% |
| Hodgdon H1000 | <<locked>> | 94% | 60,133 psi | 90% | 3386 fps | 100% |
| Hodgdon H4831 | <<locked>> | 86% | 57,870 psi | 87% | 3314 fps | 99.6% |
| Hodgdon H4831 SC | <<locked>> | 86% | 56,724 psi | 85% | 3291 fps | 99.5% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 60,220 psi | 90% | 3261 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 92% | 57,827 psi | 87% | 3451 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,623 psi | 56% | 2175 fps | 100% |
| IMR 4350 | <<locked>> | 82% | 58,262 psi | 87% | 3278 fps | 100% |
| IMR 4831 | <<locked>> | 82% | 59,045 psi | 89% | 3278 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 86% | 57,856 psi | 87% | 3287 fps | 99.6% |
| IMR 7828 SSC | <<locked>> | 88% | 57,522 psi | 86% | 3369 fps | 99.8% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 56,434 psi | 85% | 3353 fps | 99.9% |
| Lovex S071 | <<locked>> | 92% | 57,043 psi | 86% | 3238 fps | 100% |
| Norma 204 | <<locked>> | 82% | 59,915 psi | 90% | 3346 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 57,856 psi | 87% | 3376 fps | 100% |
| Norma MRP | <<locked>> | 86% | 59,799 psi | 90% | 3396 fps | 100% |
| Ramshot Grand | <<locked>> | 88% | 59,176 psi | 89% | 3392 fps | 100% |
| Ramshot Hunter | <<locked>> | 82% | 59,930 psi | 90% | 3337 fps | 100% |
| Ramshot Magnum | <<locked>> | 90% | 57,566 psi | 86% | 3307 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,609 psi | 58% | 2228 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 59,146 psi | 89% | 3432 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 94% | 58,305 psi | 87% | 3396 fps | 99.6% |
| Rottweil R 904 | <<locked>> | 84% | 56,681 psi | 85% | 3274 fps | 99.7% |
| Rottweil R 905 | <<locked>> | 86% | 59,466 psi | 89% | 3346 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 59,074 psi | 89% | 3343 fps | 100% |
| Somchem S361 | <<locked>> | 84% | 58,291 psi | 87% | 3258 fps | 99.6% |
| Somchem S365 | <<locked>> | 82% | 58,697 psi | 88% | 3268 fps | 100% |
| Somchem S385 | <<locked>> | 86% | 59,814 psi | 90% | 3310 fps | 100% |
| Vihtavuori N165 | <<locked>> | 90% | 60,089 psi | 90% | 3294 fps | 100% |
| Vihtavuori N170 | <<locked>> | 94% | 59,480 psi | 89% | 3317 fps | 97.2% |
| Vihtavuori N555 | <<locked>> | 86% | 59,016 psi | 88% | 3304 fps | 100% |
| Vihtavuori N560 | <<locked>> | 86% | 59,103 psi | 89% | 3399 fps | 99.7% |
| Vihtavuori N565 | <<locked>> | 92% | 60,234 psi | 90% | 3386 fps | 99.9% |
| Vihtavuori N568 | <<locked>> | 94% | 58,479 psi | 88% | 3399 fps | 99.3% |
| Vihtavuori N570 | <<locked>> | 96% | 60,046 psi | 90% | 3471 fps | 98.4% |
| Winchester StaBALL HD | <<locked>> | 88% | 58,392 psi | 88% | 3366 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 60,089 psi | 90% | 3310 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% | 44,585 psi | 67% | 3018 fps | 99.9% |
| Accurate MAGPRO | <<locked>> | 80% | 46,833 psi | 70% | 3163 fps | 97.4% |
| ADI AR 2209 | <<locked>> | 80% | 49,139 psi | 74% | 3176 fps | 99.5% |
| ADI AR 2213 | <<locked>> | 80% | 44,280 psi | 66% | 3104 fps | 97.8% |
| ADI AR 2217 | <<locked>> | 82% | 35,230 psi | 53% | 2871 fps | 95.2% |
| ADI AR 2218 | <<locked>> | 94% | 47,282 psi | 71% | 3241 fps | 95.9% |
| ADI AR 2225 | <<locked>> | 80% | 30,066 psi | 45% | 2756 fps | 95.9% |
| Alliant Reloder-16 | <<locked>> | 80% | 56,260 psi | 84% | 3291 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 48,878 psi | 73% | 3163 fps | 99.4% |
| Alliant Reloder-22 | <<locked>> | 80% | 44,962 psi | 67% | 3107 fps | 98.9% |
| Alliant Reloder-23 | <<locked>> | 80% | 43,627 psi | 65% | 3038 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 37,913 psi | 57% | 2969 fps | 99.7% |
| Alliant Reloder-26 | <<locked>> | 80% | 50,096 psi | 75% | 3228 fps | 100% |
| Alliant Reloder-33 | 101.2 gr | 90% | 45,121 psi | 68% | 3150 fps | 95.1% |
| Alliant Reloder-50 | <<locked>> | 96% | 48,617 psi | 73% | 3209 fps | 95.7% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 45,585 psi | 68% | 3074 fps | 95.6% |
| Bofors RP15 | <<locked>> | 80% | 41,756 psi | 63% | 3035 fps | 98.2% |
| Bofors RP30 | <<locked>> | 80% | 35,201 psi | 53% | 2881 fps | 95.2% |
| Bofors RP5 | <<locked>> | 80% | 44,962 psi | 67% | 3107 fps | 98.9% |
| Hodgdon H1000 | <<locked>> | 80% | 35,694 psi | 54% | 2890 fps | 96.1% |
| Hodgdon H4831 | <<locked>> | 80% | 46,731 psi | 70% | 3107 fps | 97.9% |
| Hodgdon H4831 SC | <<locked>> | 80% | 45,963 psi | 69% | 3087 fps | 97.7% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 52,736 psi | 79% | 3150 fps | 100% |
| Hodgdon Retumbo | 83.4 gr | 80% | 37,014 psi | 55% | 3012 fps | 97.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,166 psi | 42% | 1952 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 54,694 psi | 82% | 3219 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 55,361 psi | 83% | 3219 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 47,659 psi | 71% | 3097 fps | 98.2% |
| IMR 7828 SSC | <<locked>> | 80% | 43,062 psi | 65% | 3084 fps | 97.6% |
| IMR 8133 Enduron | <<locked>> | 88% | 36,753 psi | 55% | 2936 fps | 95.7% |
| Lovex S071 | <<locked>> | 80% | 38,203 psi | 57% | 2877 fps | 99.2% |
| Norma 204 | <<locked>> | 80% | 55,956 psi | 84% | 3281 fps | 99.9% |
| Norma 217 | <<locked>> | 84% | 32,053 psi | 48% | 2822 fps | 96% |
| Norma MRP | <<locked>> | 80% | 48,051 psi | 72% | 3189 fps | 99.9% |
| Ramshot Grand | <<locked>> | 80% | 43,381 psi | 65% | 3097 fps | 98% |
| Ramshot Hunter | <<locked>> | 80% | 56,014 psi | 84% | 3274 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 39,001 psi | 58% | 2953 fps | 98.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,964 psi | 43% | 2001 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 36,463 psi | 55% | 2979 fps | 98.6% |
| ReloadSwiss RS 80 | <<locked>> | 84% | 39,160 psi | 59% | 3002 fps | 95.2% |
| Rottweil R 904 | <<locked>> | 80% | 49,603 psi | 74% | 3143 fps | 98.9% |
| Rottweil R 905 | <<locked>> | 80% | 48,515 psi | 73% | 3153 fps | 99.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 48,167 psi | 72% | 3146 fps | 99.4% |
| Somchem S361 | <<locked>> | 80% | 50,836 psi | 76% | 3130 fps | 98.7% |
| Somchem S365 | <<locked>> | 80% | 54,897 psi | 82% | 3215 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 48,820 psi | 73% | 3123 fps | 99.8% |
| Vihtavuori N165 | <<locked>> | 80% | 42,685 psi | 64% | 2982 fps | 98.9% |
| Vihtavuori N170 | <<locked>> | 90% | 51,764 psi | 78% | 3179 fps | 95.5% |
| Vihtavuori N555 | <<locked>> | 80% | 48,211 psi | 72% | 3127 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 47,601 psi | 71% | 3186 fps | 98.2% |
| Vihtavuori N565 | <<locked>> | 80% | 39,421 psi | 59% | 2972 fps | 96.1% |
| Vihtavuori N568 | <<locked>> | 86% | 43,453 psi | 65% | 3100 fps | 96.2% |
| Vihtavuori N570 | 97.3 gr | 90% | 47,921 psi | 72% | 3235 fps | 95.5% |
| Winchester StaBALL HD | <<locked>> | 80% | 42,569 psi | 64% | 3100 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 45,165 psi | 68% | 3048 fps | 99% |
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 55 powders for 7.21 Firebird loaded with the .284 | 132gr | CutEdge Maximus. ADI AR 2218 delivers the highest muzzle velocity at 3,497 fps; across all powders the maximum-charge window runs from 2,175 fps to 3,497 fps. ADI AR 2218 gives the best case fill at 100 %, and 55 of the 55 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 132.0 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, Vihtavuori N570, Alliant Reloder-33 rank at the top here: for 7.21 Firebird with the .284 | 132gr | CutEdge Maximus 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.