Load Specifications
Load data in caliber 7.21 Firebird with .284 | 171gr | Barnes Match Burner BT bullet and 89 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 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.
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% | 57,522 psi | 86% | 2910 fps | 100% |
| Accurate 3100 | <<locked>> | 82% | 58,813 psi | 88% | 2930 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 58,987 psi | 88% | 3051 fps | 99.6% |
| Accurate 8700 | <<locked>> | 98% | 56,507 psi | 85% | 3012 fps | 99.5% |
| ADI AR 2213 | <<locked>> | 82% | 57,334 psi | 86% | 3025 fps | 100% |
| ADI AR 2213 | <<locked>> | 82% | 58,668 psi | 88% | 3045 fps | 100% |
| ADI AR 2217 | <<locked>> | 90% | 57,580 psi | 86% | 3018 fps | 100% |
| ADI AR 2217 | <<locked>> | 90% | 59,030 psi | 88% | 3038 fps | 100% |
| ADI AR 2218 | <<locked>> | 94% | 58,755 psi | 88% | 3169 fps | 100% |
| ADI AR 2218 | <<locked>> | 92% | 56,231 psi | 84% | 3123 fps | 99.9% |
| ADI AR 2225 | <<locked>> | 92% | 57,928 psi | 87% | 3038 fps | 100% |
| ADI AR 2225 | <<locked>> | 92% | 59,582 psi | 89% | 3061 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 82% | 57,928 psi | 87% | 3015 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 82% | 59,248 psi | 89% | 3035 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 84% | 60,191 psi | 90% | 2963 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 82% | 57,609 psi | 86% | 2930 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 86% | 57,740 psi | 87% | 2999 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 86% | 59,117 psi | 89% | 3015 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 90% | 56,623 psi | 85% | 3068 fps | 99.6% |
| Alliant Reloder-33 | <<locked>> | 90% | 58,508 psi | 88% | 3097 fps | 99.8% |
| Alliant Reloder-50 | <<locked>> | 94% | 57,377 psi | 86% | 3074 fps | 99.5% |
| Alliant Reloder-50 | <<locked>> | 94% | 59,190 psi | 89% | 3097 fps | 99.7% |
| Baschieri & Pellagri 109 | <<locked>> | 84% | 56,985 psi | 85% | 2986 fps | 99.7% |
| Baschieri & Pellagri 109 | <<locked>> | 84% | 58,291 psi | 87% | 3009 fps | 99.8% |
| Bofors RP15 | <<locked>> | 84% | 57,537 psi | 86% | 3012 fps | 100% |
| Bofors RP15 | <<locked>> | 84% | 58,827 psi | 88% | 3028 fps | 100% |
| Bofors RP30 | <<locked>> | 88% | 57,725 psi | 87% | 3035 fps | 100% |
| Bofors RP30 | <<locked>> | 88% | 59,161 psi | 89% | 3051 fps | 100% |
| Bofors RP5 | <<locked>> | 82% | 57,928 psi | 87% | 3015 fps | 100% |
| Bofors RP5 | <<locked>> | 82% | 59,248 psi | 89% | 3035 fps | 100% |
| Hodgdon H1000 | <<locked>> | 88% | 58,798 psi | 88% | 3031 fps | 100% |
| Hodgdon H1000 | <<locked>> | 86% | 56,333 psi | 84% | 2992 fps | 100% |
| Hodgdon H4831 | <<locked>> | 82% | 59,277 psi | 89% | 3009 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 82% | 58,305 psi | 87% | 2995 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 82% | 59,553 psi | 89% | 3015 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 86% | 57,972 psi | 87% | 3100 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 86% | 59,712 psi | 90% | 3123 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,261 psi | 57% | 1939 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,348 psi | 57% | 1946 fps | 100% |
| Hodgdon US 869 | <<locked>> | 98% | 59,422 psi | 89% | 3051 fps | 96.9% |
| Hodgdon US 869 | <<locked>> | 96% | 56,811 psi | 85% | 3012 fps | 96.5% |
| IMR 4955 Enduron | <<locked>> | 82% | 58,871 psi | 88% | 2979 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 82% | 60,060 psi | 90% | 2999 fps | 100% |
| IMR 7828 SSC | <<locked>> | 84% | 60,162 psi | 90% | 3071 fps | 100% |
| IMR 7828 SSC | <<locked>> | 82% | 57,435 psi | 86% | 3031 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 88% | 57,812 psi | 87% | 2949 fps | 97.8% |
| IMR 7977 Enduron | <<locked>> | 88% | 58,987 psi | 88% | 2969 fps | 98.1% |
| IMR 8133 Enduron | <<locked>> | 94% | 56,884 psi | 85% | 3035 fps | 100% |
| IMR 8133 Enduron | <<locked>> | 94% | 58,465 psi | 88% | 3054 fps | 100% |
| Lovex D100 | <<locked>> | 92% | 59,988 psi | 90% | 3012 fps | 97.4% |
| Lovex D100 | <<locked>> | 90% | 57,203 psi | 86% | 2969 fps | 97% |
| Lovex S071 | <<locked>> | 88% | 59,814 psi | 90% | 2943 fps | 100% |
| Lovex S071 | <<locked>> | 86% | 57,522 psi | 86% | 2910 fps | 100% |
| Norma 217 | <<locked>> | 94% | 58,668 psi | 88% | 3051 fps | 100% |
| Norma 217 | <<locked>> | 92% | 56,521 psi | 85% | 3018 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 57,914 psi | 87% | 3035 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 59,350 psi | 89% | 3058 fps | 100% |
| Ramshot LRT | <<locked>> | 94% | 57,957 psi | 87% | 3091 fps | 96.8% |
| Ramshot LRT | <<locked>> | 94% | 59,669 psi | 89% | 3117 fps | 97.2% |
| Ramshot Magnum | <<locked>> | 84% | 56,246 psi | 84% | 2959 fps | 100% |
| Ramshot Magnum | <<locked>> | 84% | 57,856 psi | 87% | 2979 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,421 psi | 59% | 1985 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,508 psi | 59% | 1991 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 86% | 58,900 psi | 88% | 3084 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 84% | 56,304 psi | 84% | 3045 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 88% | 57,682 psi | 86% | 3064 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 88% | 59,437 psi | 89% | 3087 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 92% | 59,988 psi | 90% | 3012 fps | 97.4% |
| Shooters World 50 BMG | <<locked>> | 90% | 57,203 psi | 86% | 2969 fps | 97% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 60,292 psi | 90% | 3051 fps | 99.5% |
| SNPE Vectan SP 13 | <<locked>> | 98% | 57,856 psi | 87% | 3015 fps | 99.4% |
| Vihtavuori 20N29ᴾ | <<locked>> | 100% | 53,621 psi | 80% | 2969 fps | 97.6% |
| Vihtavuori 20N29ᴾ | <<locked>> | 100% | 55,376 psi | 83% | 2995 fps | 98% |
| Vihtavuori 24N41 | <<locked>> | 96% | 59,814 psi | 90% | 3061 fps | 96.9% |
| Vihtavuori 24N41 | <<locked>> | 94% | 57,377 psi | 86% | 3022 fps | 96.5% |
| Vihtavuori N165 | <<locked>> | 84% | 58,073 psi | 87% | 2936 fps | 100% |
| Vihtavuori N165 | <<locked>> | 84% | 59,277 psi | 89% | 2956 fps | 100% |
| Vihtavuori N170 | <<locked>> | 88% | 57,769 psi | 87% | 2989 fps | 98.9% |
| Vihtavuori N170 | <<locked>> | 88% | 59,103 psi | 89% | 3009 fps | 99.2% |
| Vihtavuori N565 | <<locked>> | 86% | 59,306 psi | 89% | 3045 fps | 100% |
| Vihtavuori N565 | <<locked>> | 84% | 56,826 psi | 85% | 3005 fps | 100% |
| Vihtavuori N568 | <<locked>> | 88% | 57,827 psi | 87% | 3068 fps | 100% |
| Vihtavuori N568 | <<locked>> | 88% | 59,393 psi | 89% | 3091 fps | 100% |
| Vihtavuori N570 | <<locked>> | 90% | 59,654 psi | 89% | 3143 fps | 99.7% |
| Vihtavuori N570 | <<locked>> | 88% | 57,217 psi | 86% | 3100 fps | 99.5% |
| Winchester StaBALL HD | <<locked>> | 82% | 58,537 psi | 88% | 3012 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 82% | 60,176 psi | 90% | 3028 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 82% | 57,638 psi | 86% | 2946 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 82% | 58,827 psi | 88% | 2963 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% | 53,867 psi | 81% | 2858 fps | 100% |
| Accurate 3100 | <<locked>> | 80% | 54,998 psi | 82% | 2874 fps | 100% |
| Accurate 8700 | <<locked>> | 90% | 40,770 psi | 61% | 2723 fps | 96.1% |
| Accurate 8700 | <<locked>> | 88% | 39,146 psi | 59% | 2687 fps | 95.5% |
| ADI AR 2213 | <<locked>> | 80% | 53,388 psi | 80% | 2963 fps | 100% |
| ADI AR 2213 | <<locked>> | 80% | 54,737 psi | 82% | 2986 fps | 100% |
| ADI AR 2217 | <<locked>> | 80% | 40,495 psi | 61% | 2720 fps | 99.4% |
| ADI AR 2217 | <<locked>> | 80% | 41,597 psi | 62% | 2740 fps | 99.5% |
| ADI AR 2218 | 90.4 gr | 82% | 37,478 psi | 56% | 2730 fps | 95.3% |
| ADI AR 2218 | 90.4 gr | 82% | 38,609 psi | 58% | 2759 fps | 95.9% |
| ADI AR 2225 | <<locked>> | 80% | 37,898 psi | 57% | 2694 fps | 100% |
| ADI AR 2225 | <<locked>> | 80% | 39,117 psi | 59% | 2717 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 54,085 psi | 81% | 2959 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 55,419 psi | 83% | 2976 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 80% | 52,808 psi | 79% | 2861 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 80% | 54,041 psi | 81% | 2877 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 47,021 psi | 70% | 2835 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 48,385 psi | 73% | 2854 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 80% | 39,015 psi | 58% | 2726 fps | 95.9% |
| Alliant Reloder-33 | <<locked>> | 80% | 40,263 psi | 60% | 2749 fps | 96.4% |
| Alliant Reloder-50 | <<locked>> | 84% | 39,639 psi | 59% | 2730 fps | 95.5% |
| Alliant Reloder-50 | <<locked>> | 84% | 40,959 psi | 61% | 2756 fps | 96.1% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 50,140 psi | 75% | 2871 fps | 99% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 51,140 psi | 77% | 2887 fps | 99.2% |
| Bofors RP15 | <<locked>> | 80% | 50,488 psi | 76% | 2897 fps | 100% |
| Bofors RP15 | <<locked>> | 80% | 51,648 psi | 77% | 2917 fps | 100% |
| Bofors RP30 | <<locked>> | 80% | 44,034 psi | 66% | 2795 fps | 99.7% |
| Bofors RP30 | <<locked>> | 80% | 45,150 psi | 68% | 2818 fps | 99.8% |
| Bofors RP5 | <<locked>> | 80% | 54,085 psi | 81% | 2959 fps | 100% |
| Bofors RP5 | <<locked>> | 80% | 55,419 psi | 83% | 2976 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 44,251 psi | 66% | 2795 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 80% | 45,397 psi | 68% | 2815 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 55,521 psi | 83% | 2949 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 80% | 54,433 psi | 82% | 2936 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 80% | 55,709 psi | 84% | 2956 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 80% | 46,702 psi | 70% | 2920 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 80% | 48,225 psi | 72% | 2943 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,819 psi | 43% | 1736 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,834 psi | 43% | 1742 fps | 100% |
| Hodgdon US 869 | <<locked>> | 94% | 51,474 psi | 77% | 2920 fps | 95% |
| Hodgdon US 869 | <<locked>> | 94% | 52,968 psi | 79% | 2946 fps | 95.5% |
| IMR 4955 Enduron | <<locked>> | 80% | 55,303 psi | 83% | 2927 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 56,478 psi | 85% | 2943 fps | 100% |
| IMR 7828 SSC | <<locked>> | 80% | 52,359 psi | 78% | 2949 fps | 100% |
| IMR 7828 SSC | <<locked>> | 80% | 53,737 psi | 81% | 2972 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 82% | 47,659 psi | 71% | 2772 fps | 95.6% |
| IMR 7977 Enduron | <<locked>> | 80% | 45,527 psi | 68% | 2733 fps | 95.1% |
| IMR 8133 Enduron | <<locked>> | 80% | 35,317 psi | 53% | 2618 fps | 97.9% |
| IMR 8133 Enduron | <<locked>> | 80% | 36,376 psi | 55% | 2641 fps | 98.3% |
| Lovex D100 | <<locked>> | 88% | 51,982 psi | 78% | 2881 fps | 95.7% |
| Lovex D100 | <<locked>> | 86% | 49,748 psi | 75% | 2841 fps | 95.2% |
| Lovex S071 | <<locked>> | 80% | 46,572 psi | 70% | 2743 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 47,558 psi | 71% | 2759 fps | 100% |
| Norma 217 | <<locked>> | 80% | 36,100 psi | 54% | 2648 fps | 99.6% |
| Norma 217 | <<locked>> | 80% | 37,231 psi | 56% | 2667 fps | 99.7% |
| Ramshot Grand | <<locked>> | 80% | 53,795 psi | 81% | 2976 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 55,230 psi | 83% | 2995 fps | 100% |
| Ramshot LRT | 99 gr | 92% | 54,070 psi | 81% | 3025 fps | 95.9% |
| Ramshot LRT | 99 gr | 90% | 51,721 psi | 78% | 2979 fps | 95.3% |
| Ramshot Magnum | <<locked>> | 80% | 48,646 psi | 73% | 2841 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 49,908 psi | 75% | 2861 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,646 psi | 44% | 1778 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,660 psi | 44% | 1785 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 46,688 psi | 70% | 2894 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 48,254 psi | 72% | 2917 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 42,757 psi | 64% | 2799 fps | 98.8% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 44,106 psi | 66% | 2822 fps | 99.1% |
| Shooters World 50 BMG | <<locked>> | 88% | 51,982 psi | 78% | 2881 fps | 95.7% |
| Shooters World 50 BMG | <<locked>> | 86% | 49,748 psi | 75% | 2841 fps | 95.2% |
| SNPE Vectan SP 13 | <<locked>> | 88% | 40,001 psi | 60% | 2684 fps | 95.3% |
| SNPE Vectan SP 13 | <<locked>> | 88% | 41,234 psi | 62% | 2710 fps | 95.9% |
| Vihtavuori 20N29 | <<locked>> | 96% | 46,528 psi | 70% | 2838 fps | 95.8% |
| Vihtavuori 20N29 | <<locked>> | 94% | 44,686 psi | 67% | 2799 fps | 95.3% |
| Vihtavuori 24N41 | <<locked>> | 92% | 51,982 psi | 78% | 2930 fps | 95.1% |
| Vihtavuori 24N41 | <<locked>> | 92% | 53,388 psi | 80% | 2956 fps | 95.6% |
| Vihtavuori N165 | <<locked>> | 80% | 51,039 psi | 77% | 2831 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 52,098 psi | 78% | 2848 fps | 100% |
| Vihtavuori N170 | <<locked>> | 80% | 44,164 psi | 66% | 2743 fps | 96.1% |
| Vihtavuori N170 | <<locked>> | 80% | 45,208 psi | 68% | 2762 fps | 96.5% |
| Vihtavuori N565 | <<locked>> | 80% | 48,486 psi | 73% | 2867 fps | 99.8% |
| Vihtavuori N565 | <<locked>> | 80% | 49,734 psi | 75% | 2887 fps | 99.9% |
| Vihtavuori N568 | <<locked>> | 80% | 43,526 psi | 65% | 2808 fps | 98.6% |
| Vihtavuori N568 | <<locked>> | 80% | 44,889 psi | 67% | 2835 fps | 98.9% |
| Vihtavuori N570 | 86.4 gr | 80% | 41,756 psi | 63% | 2805 fps | 96.4% |
| Vihtavuori N570 | 86.4 gr | 80% | 42,989 psi | 64% | 2828 fps | 96.8% |
| Winchester StaBALL HD | <<locked>> | 80% | 54,389 psi | 82% | 2956 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 55,970 psi | 84% | 2976 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 53,780 psi | 81% | 2887 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 54,998 psi | 82% | 2910 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 89 powders for 7.21 Firebird loaded with the .284 | 171gr | Barnes Match Burner BT. ADI AR 2218 delivers the highest muzzle velocity at 3,169 fps; across all powders the maximum-charge window runs from 1,939 fps to 3,169 fps. Accurate 8700 gives the best case fill at 100 %, and 89 of the 89 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. Accurate 8700, Hodgdon TrailBoss, 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. ADI AR 2218, Ramshot LRT, Vihtavuori N570 rank at the top here: for 7.21 Firebird with the .284 | 171gr | Barnes Match Burner BT 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.