Load Specifications
Load data in caliber 7.21 Firebird with .284 | 150gr | RWS Speed Tip Professional bullet and 51 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ADI AR 2218, Vihtavuori N570 and Hodgdon Retumbo.
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% | 60,220 psi | 90% | 3117 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 52,707 psi | 79% | 3100 fps | 97.9% |
| Accurate MAGPRO | <<locked>> | 84% | 59,698 psi | 89% | 3245 fps | 99.9% |
| ADI AR 2209 | <<locked>> | 82% | 57,087 psi | 86% | 3153 fps | 100% |
| ADI AR 2213 | <<locked>> | 86% | 60,176 psi | 90% | 3238 fps | 100% |
| ADI AR 2217 | <<locked>> | 94% | 59,814 psi | 90% | 3219 fps | 100% |
| ADI AR 2218 | <<locked>> | 96% | 56,739 psi | 85% | 3294 fps | 99.3% |
| ADI AR 2225 | <<locked>> | 96% | 59,654 psi | 89% | 3238 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 56,782 psi | 85% | 3143 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 84% | 56,652 psi | 85% | 3166 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 86% | 58,711 psi | 88% | 3120 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 90% | 59,857 psi | 90% | 3202 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 82% | 59,988 psi | 90% | 3215 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 58,972 psi | 88% | 3268 fps | 99.3% |
| Alliant Reloder-50 | <<locked>> | 98% | 59,146 psi | 89% | 3258 fps | 99% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 60,031 psi | 90% | 3192 fps | 99.4% |
| Bofors RP15 | <<locked>> | 88% | 59,973 psi | 90% | 3219 fps | 100% |
| Bofors RP30 | <<locked>> | 92% | 59,727 psi | 90% | 3232 fps | 100% |
| Bofors RP5 | <<locked>> | 84% | 56,652 psi | 85% | 3166 fps | 100% |
| Hodgdon H1000 | <<locked>> | 90% | 57,174 psi | 86% | 3176 fps | 100% |
| Hodgdon H4831 | <<locked>> | 84% | 58,537 psi | 88% | 3159 fps | 99.9% |
| Hodgdon H4831 SC | <<locked>> | 84% | 57,377 psi | 86% | 3143 fps | 99.9% |
| Hodgdon Retumbo | <<locked>> | 90% | 59,814 psi | 90% | 3310 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,971 psi | 57% | 2054 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 84% | 58,479 psi | 88% | 3136 fps | 100% |
| IMR 7828 SSC | <<locked>> | 86% | 58,682 psi | 88% | 3222 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 90% | 57,116 psi | 86% | 3084 fps | 96.4% |
| IMR 8133 Enduron | <<locked>> | 98% | 58,537 psi | 88% | 3228 fps | 100% |
| Lovex S071 | <<locked>> | 90% | 58,479 psi | 88% | 3094 fps | 100% |
| Norma 217 | <<locked>> | 98% | 60,147 psi | 90% | 3245 fps | 100% |
| Norma MRP | <<locked>> | 82% | 56,927 psi | 85% | 3179 fps | 100% |
| Ramshot Grand | <<locked>> | 84% | 56,275 psi | 84% | 3182 fps | 100% |
| Ramshot Magnum | <<locked>> | 88% | 58,972 psi | 88% | 3163 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,073 psi | 59% | 2100 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 88% | 56,623 psi | 85% | 3228 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 60,176 psi | 90% | 3268 fps | 100% |
| Rottweil R 904 | <<locked>> | 82% | 57,290 psi | 86% | 3120 fps | 100% |
| Rottweil R 905 | <<locked>> | 82% | 56,565 psi | 85% | 3133 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 54,447 psi | 82% | 3110 fps | 97.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 60,220 psi | 90% | 3192 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 58,755 psi | 88% | 3110 fps | 99.9% |
| Somchem S385 | <<locked>> | 82% | 56,927 psi | 85% | 3100 fps | 100% |
| Vihtavuori N165 | <<locked>> | 86% | 57,029 psi | 85% | 3087 fps | 100% |
| Vihtavuori N170 | <<locked>> | 90% | 56,724 psi | 85% | 3123 fps | 97.8% |
| Vihtavuori N555 | <<locked>> | 84% | 60,350 psi | 90% | 3150 fps | 100% |
| Vihtavuori N560 | <<locked>> | 84% | 60,147 psi | 90% | 3251 fps | 100% |
| Vihtavuori N565 | <<locked>> | 88% | 57,798 psi | 87% | 3186 fps | 100% |
| Vihtavuori N568 | <<locked>> | 92% | 60,147 psi | 90% | 3268 fps | 99.9% |
| Vihtavuori N570 | <<locked>> | 92% | 57,667 psi | 86% | 3274 fps | 98.8% |
| Winchester StaBALL HD | <<locked>> | 84% | 56,304 psi | 84% | 3163 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 84% | 56,869 psi | 85% | 3100 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% | 49,414 psi | 74% | 2949 fps | 100% |
| Accurate 8700 | <<locked>> | 96% | 45,223 psi | 68% | 2959 fps | 96% |
| Accurate MAGPRO | <<locked>> | 80% | 51,851 psi | 78% | 3110 fps | 99.3% |
| ADI AR 2209 | <<locked>> | 80% | 53,403 psi | 80% | 3094 fps | 100% |
| ADI AR 2213 | <<locked>> | 80% | 48,718 psi | 73% | 3045 fps | 99.5% |
| ADI AR 2217 | <<locked>> | 80% | 36,506 psi | 55% | 2772 fps | 97.2% |
| ADI AR 2218 | 95.2 gr | 88% | 41,959 psi | 63% | 2979 fps | 95.4% |
| ADI AR 2225 | <<locked>> | 80% | 33,837 psi | 51% | 2743 fps | 99% |
| Alliant Reloder-19 | <<locked>> | 80% | 53,243 psi | 80% | 3084 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 49,472 psi | 74% | 3041 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 80% | 48,269 psi | 72% | 2959 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 42,409 psi | 64% | 2913 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 80% | 55,666 psi | 83% | 3153 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 86% | 43,627 psi | 65% | 2976 fps | 96% |
| Alliant Reloder-50 | <<locked>> | 90% | 43,961 psi | 66% | 2969 fps | 95.5% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 46,267 psi | 69% | 2943 fps | 97.1% |
| Bofors RP15 | <<locked>> | 80% | 46,151 psi | 69% | 2976 fps | 99.6% |
| Bofors RP30 | <<locked>> | 80% | 39,711 psi | 60% | 2854 fps | 98.2% |
| Bofors RP5 | <<locked>> | 80% | 49,472 psi | 74% | 3041 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 80% | 39,740 psi | 60% | 2851 fps | 98.7% |
| Hodgdon H4831 | <<locked>> | 80% | 51,126 psi | 77% | 3035 fps | 99.4% |
| Hodgdon H4831 SC | <<locked>> | 80% | 50,111 psi | 75% | 3018 fps | 99.3% |
| Hodgdon Retumbo | 81.7 gr | 80% | 41,568 psi | 62% | 2979 fps | 99.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,587 psi | 43% | 1844 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 51,401 psi | 77% | 3015 fps | 99.5% |
| IMR 7828 SSC | <<locked>> | 80% | 47,601 psi | 71% | 3028 fps | 99.4% |
| IMR 7977 Enduron | <<locked>> | 88% | 53,563 psi | 80% | 3022 fps | 95.6% |
| IMR 8133 Enduron | <<locked>> | 82% | 33,779 psi | 51% | 2720 fps | 95.9% |
| Lovex S071 | <<locked>> | 80% | 42,467 psi | 64% | 2822 fps | 100% |
| Norma 217 | <<locked>> | 80% | 31,865 psi | 48% | 2680 fps | 97.3% |
| Norma MRP | <<locked>> | 80% | 53,098 psi | 80% | 3120 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 48,472 psi | 73% | 3048 fps | 99.7% |
| Ramshot Magnum | <<locked>> | 80% | 43,816 psi | 66% | 2910 fps | 99.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,356 psi | 44% | 1883 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 41,278 psi | 62% | 2953 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 38,000 psi | 57% | 2835 fps | 96.2% |
| Rottweil R 904 | <<locked>> | 80% | 53,708 psi | 81% | 3061 fps | 99.9% |
| Rottweil R 905 | <<locked>> | 80% | 52,953 psi | 79% | 3074 fps | 100% |
| SNPE Vectan SP 13 | <<locked>> | 94% | 44,106 psi | 66% | 2910 fps | 95.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 52,605 psi | 79% | 3071 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 55,071 psi | 83% | 3051 fps | 99.8% |
| Somchem S385 | <<locked>> | 80% | 53,243 psi | 80% | 3041 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 46,905 psi | 70% | 2917 fps | 99.9% |
| Vihtavuori N170 | <<locked>> | 84% | 46,195 psi | 69% | 2927 fps | 95.2% |
| Vihtavuori N555 | <<locked>> | 80% | 53,185 psi | 80% | 3045 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 52,417 psi | 79% | 3120 fps | 99.6% |
| Vihtavuori N565 | <<locked>> | 80% | 44,005 psi | 66% | 2933 fps | 98.6% |
| Vihtavuori N568 | <<locked>> | 80% | 39,015 psi | 58% | 2854 fps | 95.9% |
| Vihtavuori N570 | 89 gr | 84% | 43,062 psi | 65% | 2982 fps | 95.3% |
| Winchester StaBALL HD | <<locked>> | 80% | 48,399 psi | 73% | 3041 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 49,443 psi | 74% | 2976 fps | 99.9% |
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 51 powders for 7.21 Firebird loaded with the .284 | 150gr | RWS Speed Tip Professional. Hodgdon Retumbo delivers the highest muzzle velocity at 3,310 fps; across all powders the maximum-charge window runs from 2,054 fps to 3,310 fps. Accurate 8700 gives the best case fill at 100 %, and 51 of the 51 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 1:10.0 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, Vihtavuori N570, Hodgdon Retumbo rank at the top here: for 7.21 Firebird with the .284 | 150gr | RWS Speed Tip Professional 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.