Load Specifications
Load data in caliber 7.21 Firebird with .284 | 150gr | Remington PSP Core-Lokt bullet and 50 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.
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Max Load - Barrel Length: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 84% | 58,044 psi | 87% | 3084 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 54,969 psi | 82% | 3133 fps | 98.4% |
| Accurate MAGPRO | <<locked>> | 82% | 57,363 psi | 86% | 3205 fps | 99.8% |
| ADI AR 2209 | <<locked>> | 82% | 58,798 psi | 88% | 3179 fps | 100% |
| ADI AR 2213 | <<locked>> | 84% | 57,914 psi | 87% | 3202 fps | 100% |
| ADI AR 2217 | <<locked>> | 92% | 57,783 psi | 87% | 3186 fps | 100% |
| ADI AR 2218 | <<locked>> | 96% | 59,016 psi | 88% | 3330 fps | 99.6% |
| ADI AR 2225 | <<locked>> | 94% | 57,885 psi | 87% | 3209 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 58,233 psi | 87% | 3166 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 84% | 58,494 psi | 88% | 3192 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 84% | 56,724 psi | 85% | 3087 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 88% | 57,885 psi | 87% | 3173 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 56,869 psi | 85% | 3228 fps | 99.1% |
| Alliant Reloder-50 | <<locked>> | 96% | 57,363 psi | 86% | 3225 fps | 98.8% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 57,870 psi | 87% | 3156 fps | 99.3% |
| Bofors RP15 | <<locked>> | 86% | 57,870 psi | 87% | 3182 fps | 100% |
| Bofors RP30 | <<locked>> | 90% | 57,856 psi | 87% | 3199 fps | 100% |
| Bofors RP5 | <<locked>> | 84% | 58,494 psi | 88% | 3192 fps | 100% |
| Hodgdon H1000 | <<locked>> | 90% | 59,205 psi | 89% | 3202 fps | 100% |
| Hodgdon H4831 | <<locked>> | 84% | 60,089 psi | 90% | 3186 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 84% | 59,146 psi | 89% | 3173 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 88% | 57,856 psi | 87% | 3274 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,101 psi | 57% | 2064 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 84% | 59,770 psi | 90% | 3156 fps | 100% |
| IMR 7828 SSC | <<locked>> | 84% | 56,550 psi | 85% | 3186 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 90% | 58,740 psi | 88% | 3114 fps | 96.9% |
| IMR 8133 Enduron | <<locked>> | 96% | 56,811 psi | 85% | 3196 fps | 100% |
| Lovex S071 | <<locked>> | 90% | 60,321 psi | 90% | 3117 fps | 100% |
| Norma 217 | <<locked>> | 96% | 58,407 psi | 88% | 3219 fps | 100% |
| Norma MRP | <<locked>> | 82% | 58,842 psi | 88% | 3209 fps | 100% |
| Ramshot Grand | <<locked>> | 84% | 58,305 psi | 87% | 3212 fps | 100% |
| Ramshot Magnum | <<locked>> | 86% | 56,782 psi | 85% | 3130 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,189 psi | 59% | 2113 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 88% | 59,001 psi | 88% | 3258 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 57,885 psi | 87% | 3228 fps | 99.9% |
| Rottweil R 904 | <<locked>> | 82% | 58,740 psi | 88% | 3146 fps | 100% |
| Rottweil R 905 | <<locked>> | 82% | 58,291 psi | 87% | 3159 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 56,478 psi | 85% | 3143 fps | 98.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 82% | 57,957 psi | 87% | 3156 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 60,292 psi | 90% | 3133 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 58,537 psi | 88% | 3123 fps | 100% |
| Vihtavuori N165 | <<locked>> | 86% | 58,740 psi | 88% | 3110 fps | 100% |
| Vihtavuori N170 | <<locked>> | 90% | 58,523 psi | 88% | 3153 fps | 98.2% |
| Vihtavuori N555 | <<locked>> | 82% | 58,421 psi | 88% | 3120 fps | 100% |
| Vihtavuori N560 | <<locked>> | 82% | 58,044 psi | 87% | 3219 fps | 100% |
| Vihtavuori N565 | <<locked>> | 88% | 59,698 psi | 89% | 3215 fps | 100% |
| Vihtavuori N568 | <<locked>> | 90% | 58,160 psi | 87% | 3232 fps | 99.8% |
| Vihtavuori N570 | <<locked>> | 92% | 59,799 psi | 90% | 3304 fps | 99.2% |
| Winchester StaBALL HD | <<locked>> | 84% | 58,537 psi | 88% | 3189 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 84% | 58,363 psi | 87% | 3123 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% | 50,720 psi | 76% | 2972 fps | 100% |
| Accurate 8700 | <<locked>> | 94% | 43,816 psi | 66% | 2923 fps | 95.7% |
| Accurate MAGPRO | <<locked>> | 80% | 53,490 psi | 80% | 3140 fps | 99.5% |
| ADI AR 2209 | <<locked>> | 80% | 54,955 psi | 82% | 3117 fps | 100% |
| ADI AR 2213 | <<locked>> | 80% | 50,227 psi | 75% | 3068 fps | 99.7% |
| ADI AR 2217 | <<locked>> | 80% | 37,681 psi | 56% | 2799 fps | 97.7% |
| ADI AR 2218 | 97.9 gr | 88% | 43,613 psi | 65% | 3018 fps | 96.3% |
| ADI AR 2225 | <<locked>> | 80% | 35,114 psi | 53% | 2772 fps | 99.3% |
| Alliant Reloder-19 | <<locked>> | 80% | 54,549 psi | 82% | 3107 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 50,966 psi | 76% | 3068 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 80% | 49,690 psi | 74% | 2982 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 43,961 psi | 66% | 2940 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 84% | 42,134 psi | 63% | 2936 fps | 95.6% |
| Alliant Reloder-50 | <<locked>> | 88% | 42,583 psi | 64% | 2933 fps | 95.1% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 47,529 psi | 71% | 2969 fps | 97.5% |
| Bofors RP15 | <<locked>> | 80% | 47,456 psi | 71% | 3002 fps | 99.8% |
| Bofors RP30 | <<locked>> | 80% | 40,988 psi | 61% | 2881 fps | 98.5% |
| Bofors RP5 | <<locked>> | 80% | 50,966 psi | 76% | 3068 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 41,234 psi | 62% | 2884 fps | 99.1% |
| Hodgdon H4831 | <<locked>> | 80% | 52,504 psi | 79% | 3061 fps | 99.6% |
| Hodgdon H4831 SC | <<locked>> | 80% | 51,503 psi | 77% | 3045 fps | 99.5% |
| Hodgdon Retumbo | 84 gr | 80% | 43,178 psi | 65% | 3009 fps | 99.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,558 psi | 43% | 1850 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 52,707 psi | 79% | 3038 fps | 99.7% |
| IMR 7828 SSC | <<locked>> | 80% | 49,153 psi | 74% | 3054 fps | 99.6% |
| IMR 7977 Enduron | <<locked>> | 86% | 51,474 psi | 77% | 2989 fps | 95.2% |
| IMR 8133 Enduron | <<locked>> | 80% | 32,648 psi | 49% | 2684 fps | 95.5% |
| Lovex S071 | <<locked>> | 80% | 43,816 psi | 66% | 2844 fps | 100% |
| Norma 217 | <<locked>> | 80% | 33,301 psi | 50% | 2717 fps | 98% |
| Norma MRP | <<locked>> | 80% | 54,824 psi | 82% | 3146 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 50,111 psi | 75% | 3074 fps | 99.8% |
| Ramshot Magnum | <<locked>> | 80% | 45,368 psi | 68% | 2936 fps | 99.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,443 psi | 44% | 1896 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 43,120 psi | 65% | 2982 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 39,624 psi | 59% | 2867 fps | 96.8% |
| Rottweil R 904 | <<locked>> | 80% | 55,143 psi | 83% | 3087 fps | 100% |
| Rottweil R 905 | <<locked>> | 80% | 54,491 psi | 82% | 3100 fps | 100% |
| SNPE Vectan SP 13 | <<locked>> | 94% | 45,890 psi | 69% | 2946 fps | 95.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 54,143 psi | 81% | 3094 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 56,434 psi | 85% | 3074 fps | 99.9% |
| Somchem S385 | <<locked>> | 80% | 54,679 psi | 82% | 3064 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 48,124 psi | 72% | 2940 fps | 100% |
| Vihtavuori N170 | <<locked>> | 84% | 47,645 psi | 71% | 2956 fps | 95.8% |
| Vihtavuori N555 | <<locked>> | 80% | 54,650 psi | 82% | 3064 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 54,085 psi | 81% | 3150 fps | 99.8% |
| Vihtavuori N565 | <<locked>> | 80% | 45,426 psi | 68% | 2959 fps | 98.9% |
| Vihtavuori N568 | <<locked>> | 80% | 40,495 psi | 61% | 2884 fps | 96.6% |
| Vihtavuori N570 | 91.5 gr | 84% | 44,759 psi | 67% | 3015 fps | 96% |
| Winchester StaBALL HD | <<locked>> | 80% | 50,401 psi | 76% | 3068 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 50,792 psi | 76% | 2999 fps | 100% |
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 50 powders for 7.21 Firebird loaded with the .284 | 150gr | Remington PSP Core-Lokt. ADI AR 2218 delivers the highest muzzle velocity at 3,330 fps; across all powders the maximum-charge window runs from 2,064 fps to 3,330 fps. Accurate 8700 gives the best case fill at 100 %, and 50 of the 50 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 150.0 gr projectile in 0.284" calls for a 1:12.0 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 | 150gr | Remington PSP Core-Lokt 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.