Load Specifications
Load data in caliber 7.21 Firebird with .284 | 135gr | CutEdge ER Raptor bullet and 61 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% | 57,972 psi | 87% | 3225 fps | 100% |
| Accurate High Country | <<locked>> | 84% | 56,347 psi | 84% | 3337 fps | 99.8% |
| Accurate MAGPRO | <<locked>> | 86% | 57,479 psi | 86% | 3343 fps | 99.4% |
| ADI AR 2209 | <<locked>> | 86% | 59,408 psi | 89% | 3330 fps | 100% |
| ADI AR 2213 | <<locked>> | 88% | 58,233 psi | 87% | 3346 fps | 99.9% |
| ADI AR 2217 | <<locked>> | 96% | 57,188 psi | 86% | 3314 fps | 100% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 58,305 psi | 87% | 3448 fps | 98.8% |
| ADI AR 2225 | <<locked>> | 98% | 56,333 psi | 84% | 3337 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 86% | 59,567 psi | 89% | 3323 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 82% | 59,393 psi | 89% | 3314 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 58,914 psi | 88% | 3314 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 88% | 58,508 psi | 88% | 3337 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 88% | 56,492 psi | 85% | 3235 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 92% | 57,276 psi | 86% | 3314 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 84% | 57,305 psi | 86% | 3323 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 60,307 psi | 90% | 3419 fps | 98.8% |
| Alliant Reloder-50ᴾ | <<locked>> | 100% | 55,390 psi | 83% | 3320 fps | 97.5% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 58,813 psi | 88% | 3297 fps | 98.6% |
| Bofors RP15 | <<locked>> | 90% | 57,870 psi | 87% | 3323 fps | 100% |
| Bofors RP30 | <<locked>> | 94% | 56,985 psi | 85% | 3327 fps | 99.9% |
| Bofors RP5 | <<locked>> | 88% | 58,508 psi | 88% | 3337 fps | 100% |
| Hodgdon H1000 | <<locked>> | 94% | 58,900 psi | 88% | 3340 fps | 100% |
| Hodgdon H4831 | <<locked>> | 86% | 56,927 psi | 85% | 3271 fps | 99.5% |
| Hodgdon H4831 SC | <<locked>> | 88% | 59,886 psi | 90% | 3317 fps | 99.7% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 59,379 psi | 89% | 3222 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 92% | 56,594 psi | 85% | 3409 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,652 psi | 56% | 2146 fps | 100% |
| IMR 4350 | <<locked>> | 82% | 57,522 psi | 86% | 3238 fps | 100% |
| IMR 4831 | <<locked>> | 82% | 58,218 psi | 87% | 3238 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 86% | 57,101 psi | 86% | 3245 fps | 99.6% |
| IMR 7828 SSC | <<locked>> | 88% | 56,507 psi | 85% | 3323 fps | 99.8% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 55,129 psi | 83% | 3307 fps | 99.8% |
| Lovex S070 | <<locked>> | 82% | 59,727 psi | 90% | 3271 fps | 100% |
| Lovex S071 | <<locked>> | 94% | 59,785 psi | 90% | 3251 fps | 100% |
| Norma 204 | <<locked>> | 82% | 59,219 psi | 89% | 3304 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 56,521 psi | 85% | 3333 fps | 100% |
| Norma MRP | <<locked>> | 86% | 58,827 psi | 88% | 3353 fps | 100% |
| Norma URP | <<locked>> | 82% | 60,017 psi | 90% | 3287 fps | 100% |
| Ramshot Grand | <<locked>> | 88% | 57,972 psi | 87% | 3346 fps | 99.9% |
| Ramshot Hunter | <<locked>> | 82% | 59,219 psi | 89% | 3297 fps | 100% |
| Ramshot Magnum | <<locked>> | 90% | 56,550 psi | 85% | 3264 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,522 psi | 58% | 2195 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 57,783 psi | 87% | 3389 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 94% | 56,942 psi | 85% | 3350 fps | 99.5% |
| Rottweil R 904 | <<locked>> | 86% | 59,785 psi | 90% | 3297 fps | 99.9% |
| Rottweil R 905 | <<locked>> | 86% | 58,784 psi | 88% | 3307 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 59,727 psi | 90% | 3271 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 60,249 psi | 90% | 3219 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 58,392 psi | 88% | 3304 fps | 100% |
| Somchem S361 | <<locked>> | 84% | 57,522 psi | 86% | 3219 fps | 99.6% |
| Somchem S365 | <<locked>> | 82% | 57,798 psi | 87% | 3228 fps | 100% |
| Somchem S385 | <<locked>> | 86% | 59,045 psi | 89% | 3268 fps | 100% |
| Vihtavuori N165 | <<locked>> | 90% | 59,059 psi | 89% | 3251 fps | 100% |
| Vihtavuori N170 | <<locked>> | 94% | 58,610 psi | 88% | 3274 fps | 97.1% |
| Vihtavuori N555 | <<locked>> | 86% | 58,073 psi | 87% | 3264 fps | 100% |
| Vihtavuori N560 | <<locked>> | 86% | 58,175 psi | 87% | 3360 fps | 99.7% |
| Vihtavuori N565 | <<locked>> | 92% | 59,263 psi | 89% | 3346 fps | 99.9% |
| Vihtavuori N568 | <<locked>> | 94% | 57,246 psi | 86% | 3353 fps | 99.2% |
| Vihtavuori N570 | <<locked>> | 96% | 58,798 psi | 88% | 3425 fps | 98.2% |
| Winchester StaBALL HD | <<locked>> | 88% | 57,058 psi | 86% | 3327 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 59,248 psi | 89% | 3268 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% | 43,976 psi | 66% | 2982 fps | 99.9% |
| Accurate High Country | <<locked>> | 80% | 48,747 psi | 73% | 3192 fps | 98.9% |
| Accurate MAGPRO | <<locked>> | 80% | 46,021 psi | 69% | 3127 fps | 97.4% |
| ADI AR 2209 | <<locked>> | 80% | 48,341 psi | 72% | 3133 fps | 99.4% |
| ADI AR 2213 | <<locked>> | 80% | 43,526 psi | 65% | 3064 fps | 97.8% |
| ADI AR 2217 | <<locked>> | 82% | 34,621 psi | 52% | 2835 fps | 95.1% |
| ADI AR 2218 | <<locked>> | 94% | 46,325 psi | 69% | 3199 fps | 95.6% |
| ADI AR 2225 | <<locked>> | 80% | 29,501 psi | 44% | 2720 fps | 95.8% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 48,747 psi | 73% | 3136 fps | 99.5% |
| Alliant Reloder-16 | <<locked>> | 80% | 55,680 psi | 83% | 3255 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 48,254 psi | 72% | 3127 fps | 99.4% |
| Alliant Reloder-22 | <<locked>> | 80% | 44,208 psi | 66% | 3068 fps | 98.9% |
| Alliant Reloder-23 | <<locked>> | 80% | 42,917 psi | 64% | 3002 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 37,159 psi | 56% | 2930 fps | 99.7% |
| Alliant Reloder-26 | <<locked>> | 80% | 49,139 psi | 74% | 3189 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 47,645 psi | 71% | 3182 fps | 96% |
| Alliant Reloder-50 | <<locked>> | 96% | 47,456 psi | 71% | 3166 fps | 95.4% |
| Baschieri & Pellagri 109 | <<locked>> | 82% | 44,991 psi | 67% | 3035 fps | 95.5% |
| Bofors RP15 | <<locked>> | 80% | 41,118 psi | 62% | 2995 fps | 98.1% |
| Bofors RP30 | <<locked>> | 80% | 34,606 psi | 52% | 2848 fps | 95.1% |
| Bofors RP5 | <<locked>> | 80% | 44,208 psi | 66% | 3068 fps | 98.9% |
| Hodgdon H1000 | <<locked>> | 80% | 35,201 psi | 53% | 2854 fps | 96% |
| Hodgdon H4831 | <<locked>> | 80% | 46,224 psi | 69% | 3071 fps | 97.9% |
| Hodgdon H4831 SC | <<locked>> | 80% | 45,252 psi | 68% | 3048 fps | 97.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 51,982 psi | 78% | 3110 fps | 100% |
| Hodgdon Retumbo | 81.1 gr | 80% | 36,303 psi | 54% | 2972 fps | 97.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,210 psi | 42% | 1926 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 53,925 psi | 81% | 3179 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 54,476 psi | 82% | 3179 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 46,949 psi | 70% | 3058 fps | 98.2% |
| IMR 7828 SSC | <<locked>> | 80% | 42,293 psi | 63% | 3045 fps | 97.5% |
| IMR 8133 Enduron | <<locked>> | 88% | 36,027 psi | 54% | 2900 fps | 95.6% |
| Lovex S070 | <<locked>> | 80% | 55,985 psi | 84% | 3212 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 37,637 psi | 56% | 2841 fps | 99.1% |
| Norma 204 | <<locked>> | 80% | 55,201 psi | 83% | 3238 fps | 99.9% |
| Norma 217 | <<locked>> | 84% | 31,401 psi | 47% | 2785 fps | 95.9% |
| Norma MRP | <<locked>> | 80% | 47,297 psi | 71% | 3150 fps | 99.9% |
| Norma URP | <<locked>> | 80% | 56,159 psi | 84% | 3228 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 42,627 psi | 64% | 3058 fps | 98% |
| Ramshot Hunter | <<locked>> | 80% | 55,288 psi | 83% | 3235 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 38,203 psi | 57% | 2913 fps | 98.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,906 psi | 43% | 1972 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 35,737 psi | 54% | 2940 fps | 98.5% |
| ReloadSwiss RS 80 | 91.9 gr | 84% | 38,363 psi | 57% | 2963 fps | 95% |
| Rottweil R 904 | <<locked>> | 80% | 48,965 psi | 73% | 3104 fps | 98.9% |
| Rottweil R 905 | <<locked>> | 80% | 47,703 psi | 72% | 3110 fps | 99.4% |
| Shooters World SW4350 | <<locked>> | 80% | 55,985 psi | 84% | 3212 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 56,202 psi | 84% | 3156 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 47,355 psi | 71% | 3107 fps | 99.4% |
| Somchem S361 | <<locked>> | 80% | 50,140 psi | 75% | 3087 fps | 98.6% |
| Somchem S365 | <<locked>> | 80% | 53,983 psi | 81% | 3173 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 48,080 psi | 72% | 3081 fps | 99.8% |
| Vihtavuori N165 | <<locked>> | 80% | 42,119 psi | 63% | 2946 fps | 98.9% |
| Vihtavuori N170 | <<locked>> | 90% | 50,952 psi | 76% | 3136 fps | 95.3% |
| Vihtavuori N555 | <<locked>> | 80% | 47,485 psi | 71% | 3091 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 46,920 psi | 70% | 3146 fps | 98.1% |
| Vihtavuori N565 | <<locked>> | 80% | 38,754 psi | 58% | 2933 fps | 96% |
| Vihtavuori N568 | <<locked>> | 86% | 42,612 psi | 64% | 3064 fps | 96% |
| Vihtavuori N570 | 94.7 gr | 90% | 46,978 psi | 70% | 3196 fps | 95.3% |
| Winchester StaBALL HD | <<locked>> | 80% | 41,640 psi | 62% | 3061 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 44,483 psi | 67% | 3009 fps | 98.9% |
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 61 powders for 7.21 Firebird loaded with the .284 | 135gr | CutEdge ER Raptor. ADI AR 2218 delivers the highest muzzle velocity at 3,448 fps; across all powders the maximum-charge window runs from 2,146 fps to 3,448 fps. ADI AR 2218 gives the best case fill at 100 %, and 61 of the 61 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 135.0 gr projectile in 0.284" calls for a 1:8.5 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 | 135gr | CutEdge ER Raptor 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.