Load Specifications
Load data in caliber 7.21 Firebird with .284 | 177gr | Brenneke TIG bullet and 38 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ADI AR 2218, Ramshot LRT and Alliant Reloder-50.
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>> | 82% | 60,075 psi | 90% | 2904 fps | 100% |
| Accurate 8700 | <<locked>> | 98% | 58,378 psi | 88% | 3002 fps | 99.8% |
| ADI AR 2213 | <<locked>> | 82% | 60,205 psi | 90% | 3025 fps | 100% |
| ADI AR 2217 | <<locked>> | 88% | 56,797 psi | 85% | 2963 fps | 100% |
| ADI AR 2218 | <<locked>> | 92% | 58,189 psi | 87% | 3117 fps | 100% |
| ADI AR 2225 | <<locked>> | 90% | 57,334 psi | 86% | 2986 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 82% | 59,074 psi | 89% | 2904 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 84% | 56,797 psi | 85% | 2940 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 90% | 60,176 psi | 90% | 3084 fps | 100% |
| Alliant Reloder-50 | <<locked>> | 92% | 56,913 psi | 85% | 3025 fps | 99.6% |
| Baschieri & Pellagri 109 | <<locked>> | 84% | 59,466 psi | 89% | 2986 fps | 100% |
| Bofors RP15 | <<locked>> | 84% | 60,307 psi | 90% | 3009 fps | 100% |
| Bofors RP30 | <<locked>> | 86% | 56,884 psi | 85% | 2976 fps | 100% |
| Hodgdon H1000 | <<locked>> | 86% | 57,986 psi | 87% | 2976 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 84% | 57,421 psi | 86% | 3045 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,377 psi | 58% | 1919 fps | 100% |
| Hodgdon US 869 | <<locked>> | 96% | 58,494 psi | 88% | 3002 fps | 97.2% |
| IMR 7828 SSC | <<locked>> | 82% | 58,987 psi | 88% | 3012 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 88% | 60,307 psi | 90% | 2953 fps | 98.6% |
| IMR 8133 Enduron | <<locked>> | 94% | 60,263 psi | 90% | 3041 fps | 100% |
| Lovex D100 | <<locked>> | 90% | 58,740 psi | 88% | 2956 fps | 97.7% |
| Lovex S071 | <<locked>> | 86% | 58,769 psi | 88% | 2887 fps | 100% |
| Norma 217 | <<locked>> | 92% | 58,349 psi | 87% | 3002 fps | 100% |
| Ramshot LRT | <<locked>> | 92% | 57,276 psi | 86% | 3038 fps | 97.1% |
| Ramshot Magnum | <<locked>> | 84% | 59,335 psi | 89% | 2959 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,537 psi | 59% | 1962 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 84% | 58,001 psi | 87% | 3025 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 86% | 56,884 psi | 85% | 3009 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 90% | 58,740 psi | 88% | 2956 fps | 97.7% |
| SNPE Vectan SP 13 | <<locked>> | 98% | 59,582 psi | 89% | 3002 fps | 99.7% |
| Vihtavuori 20N29ᴾ | <<locked>> | 100% | 57,188 psi | 86% | 2986 fps | 98.6% |
| Vihtavuori 24N41 | <<locked>> | 94% | 59,059 psi | 89% | 3012 fps | 97.3% |
| Vihtavuori N165 | <<locked>> | 82% | 56,855 psi | 85% | 2877 fps | 100% |
| Vihtavuori N170 | <<locked>> | 86% | 56,782 psi | 85% | 2936 fps | 99.1% |
| Vihtavuori N565 | <<locked>> | 84% | 58,349 psi | 87% | 2989 fps | 100% |
| Vihtavuori N568 | <<locked>> | 86% | 57,000 psi | 85% | 3012 fps | 100% |
| Vihtavuori N570 | <<locked>> | 88% | 59,030 psi | 88% | 3087 fps | 99.8% |
| Winchester Supreme 780 | <<locked>> | 82% | 60,278 psi | 90% | 2940 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% | 56,362 psi | 84% | 2851 fps | 100% |
| Accurate 8700 | <<locked>> | 86% | 37,724 psi | 57% | 2618 fps | 95.4% |
| ADI AR 2213 | <<locked>> | 80% | 56,188 psi | 84% | 2963 fps | 100% |
| ADI AR 2217 | <<locked>> | 80% | 42,917 psi | 64% | 2730 fps | 99.8% |
| ADI AR 2218 | 88.3 gr | 80% | 37,043 psi | 56% | 2687 fps | 95.8% |
| ADI AR 2225 | <<locked>> | 80% | 40,350 psi | 60% | 2703 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 80% | 55,434 psi | 83% | 2854 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 49,661 psi | 74% | 2835 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 80% | 41,640 psi | 62% | 2746 fps | 97.2% |
| Alliant Reloder-50 | 91.9 gr | 82% | 39,465 psi | 59% | 2687 fps | 95.9% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 52,330 psi | 78% | 2871 fps | 99.5% |
| Bofors RP15 | <<locked>> | 80% | 52,982 psi | 79% | 2897 fps | 100% |
| Bofors RP30 | <<locked>> | 80% | 46,514 psi | 70% | 2802 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 46,804 psi | 70% | 2799 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 80% | 49,690 psi | 74% | 2923 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,863 psi | 43% | 1716 fps | 100% |
| Hodgdon US 869 | <<locked>> | 92% | 50,836 psi | 76% | 2871 fps | 95.4% |
| IMR 7828 SSC | <<locked>> | 80% | 55,027 psi | 82% | 2953 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 80% | 46,615 psi | 70% | 2720 fps | 95.9% |
| IMR 8133 Enduron | <<locked>> | 80% | 37,608 psi | 56% | 2631 fps | 98.9% |
| Lovex D100 | <<locked>> | 84% | 47,514 psi | 71% | 2766 fps | 95% |
| Lovex S071 | <<locked>> | 80% | 48,791 psi | 73% | 2740 fps | 100% |
| Norma 217 | <<locked>> | 80% | 38,551 psi | 58% | 2661 fps | 100% |
| Ramshot LRT | 96.9 gr | 88% | 49,661 psi | 74% | 2907 fps | 95.2% |
| Ramshot Magnum | <<locked>> | 80% | 51,387 psi | 77% | 2844 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,834 psi | 45% | 1759 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 49,951 psi | 75% | 2900 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 45,585 psi | 68% | 2815 fps | 99.5% |
| Shooters World 50 BMG | <<locked>> | 84% | 47,514 psi | 71% | 2766 fps | 95% |
| SNPE Vectan SP 13 | <<locked>> | 86% | 39,595 psi | 59% | 2638 fps | 95.7% |
| Vihtavuori 20N29 | <<locked>> | 92% | 42,975 psi | 64% | 2726 fps | 95.1% |
| Vihtavuori 24N41 | <<locked>> | 90% | 51,184 psi | 77% | 2881 fps | 95.4% |
| Vihtavuori N165 | <<locked>> | 80% | 53,374 psi | 80% | 2828 fps | 100% |
| Vihtavuori N170 | <<locked>> | 80% | 46,398 psi | 70% | 2753 fps | 97.2% |
| Vihtavuori N565 | <<locked>> | 80% | 50,966 psi | 76% | 2867 fps | 100% |
| Vihtavuori N568 | <<locked>> | 80% | 46,151 psi | 69% | 2822 fps | 99.3% |
| Vihtavuori N570 | <<locked>> | 80% | 44,425 psi | 67% | 2822 fps | 97.6% |
| Winchester Supreme 780 | <<locked>> | 80% | 56,333 psi | 84% | 2887 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 38 powders for 7.21 Firebird loaded with the .284 | 177gr | Brenneke TIG. ADI AR 2218 delivers the highest muzzle velocity at 3,117 fps; across all powders the maximum-charge window runs from 1,919 fps to 3,117 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 38 of the 38 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (460 MPa), the top charges use 58–90 %, leaving at least 10 % headroom. The 177.0 gr projectile in 0.284" calls for a 1:11.5 twist; slower twists will usually not stabilise this weight. Hodgdon TrailBoss, ReloadSwiss RS 14, Vihtavuori 20N29 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, Ramshot LRT, Alliant Reloder-50 rank at the top here: for 7.21 Firebird with the .284 | 177gr | Brenneke TIG 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.