Load Specifications
Load data in caliber 7.21 Firebird with .284 | 168gr | Berger VLD Hunting bullet and 46 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.
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Max Load - Barrel Length: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 82% | 56,898 psi | 85% | 2927 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 58,088 psi | 87% | 3058 fps | 99.5% |
| Accurate MAGPRO | <<locked>> | 82% | 60,249 psi | 90% | 3110 fps | 100% |
| ADI AR 2213 | <<locked>> | 82% | 56,666 psi | 85% | 3038 fps | 100% |
| ADI AR 2217 | <<locked>> | 90% | 56,826 psi | 85% | 3031 fps | 100% |
| ADI AR 2218 | <<locked>> | 94% | 58,030 psi | 87% | 3179 fps | 99.9% |
| ADI AR 2225 | <<locked>> | 92% | 57,087 psi | 86% | 3051 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 82% | 57,290 psi | 86% | 3028 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 84% | 59,524 psi | 89% | 2979 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 86% | 57,058 psi | 86% | 3012 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 92% | 60,104 psi | 90% | 3146 fps | 99.8% |
| Alliant Reloder-50 | <<locked>> | 94% | 56,449 psi | 85% | 3081 fps | 99.3% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 60,263 psi | 90% | 3058 fps | 99.8% |
| Bofors RP15 | <<locked>> | 84% | 56,898 psi | 85% | 3025 fps | 100% |
| Bofors RP30 | <<locked>> | 88% | 56,985 psi | 85% | 3045 fps | 100% |
| Bofors RP5 | <<locked>> | 82% | 57,290 psi | 86% | 3028 fps | 100% |
| Hodgdon H1000 | <<locked>> | 88% | 58,030 psi | 87% | 3045 fps | 100% |
| Hodgdon H4831 | <<locked>> | 82% | 58,653 psi | 88% | 3022 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 82% | 57,696 psi | 86% | 3009 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 86% | 57,130 psi | 86% | 3114 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 38,159 psi | 57% | 1952 fps | 100% |
| Hodgdon US 869 | <<locked>> | 98% | 58,610 psi | 88% | 3061 fps | 96.6% |
| IMR 4955 Enduron | <<locked>> | 82% | 58,349 psi | 87% | 2992 fps | 100% |
| IMR 7828 SSC | <<locked>> | 84% | 59,451 psi | 89% | 3084 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 88% | 57,246 psi | 86% | 2963 fps | 97.6% |
| IMR 8133 Enduron | <<locked>> | 96% | 59,988 psi | 90% | 3104 fps | 100% |
| Lovex D100 | <<locked>> | 92% | 59,263 psi | 89% | 3022 fps | 97.1% |
| Lovex S071 | <<locked>> | 88% | 59,176 psi | 89% | 2959 fps | 100% |
| Norma 217 | <<locked>> | 94% | 57,812 psi | 87% | 3064 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 57,145 psi | 86% | 3051 fps | 100% |
| Ramshot LRT | <<locked>> | 94% | 57,363 psi | 86% | 3100 fps | 96.5% |
| Ramshot Magnum | <<locked>> | 86% | 59,843 psi | 90% | 3031 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 39,320 psi | 59% | 1998 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 86% | 58,030 psi | 87% | 3097 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 88% | 56,869 psi | 85% | 3077 fps | 100% |
| Shooters World 50 BMG | <<locked>> | 92% | 59,263 psi | 89% | 3022 fps | 97.1% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 59,437 psi | 89% | 3061 fps | 99.4% |
| Vihtavuori 20N29ᴾ | <<locked>> | 100% | 52,794 psi | 79% | 2972 fps | 97.2% |
| Vihtavuori 24N41 | <<locked>> | 96% | 59,219 psi | 89% | 3074 fps | 96.6% |
| Vihtavuori N165 | <<locked>> | 84% | 57,464 psi | 86% | 2949 fps | 100% |
| Vihtavuori N170 | <<locked>> | 88% | 57,290 psi | 86% | 3002 fps | 98.7% |
| Vihtavuori N565 | <<locked>> | 86% | 58,581 psi | 88% | 3054 fps | 100% |
| Vihtavuori N568 | <<locked>> | 88% | 57,043 psi | 86% | 3077 fps | 100% |
| Vihtavuori N570 | <<locked>> | 90% | 59,030 psi | 88% | 3156 fps | 99.6% |
| Winchester StaBALL HD | <<locked>> | 82% | 57,696 psi | 86% | 3025 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 82% | 57,029 psi | 85% | 2959 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% | 53,272 psi | 80% | 2874 fps | 100% |
| Accurate 8700 | <<locked>> | 90% | 40,292 psi | 60% | 2733 fps | 95.7% |
| Accurate MAGPRO | <<locked>> | 80% | 56,260 psi | 84% | 3048 fps | 100% |
| ADI AR 2213 | <<locked>> | 80% | 52,765 psi | 79% | 2976 fps | 100% |
| ADI AR 2217 | <<locked>> | 80% | 39,958 psi | 60% | 2730 fps | 99.2% |
| ADI AR 2218 | 90.7 gr | 84% | 39,842 psi | 60% | 2812 fps | 96.2% |
| ADI AR 2225 | <<locked>> | 80% | 37,333 psi | 56% | 2707 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 53,476 psi | 80% | 2972 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 80% | 52,228 psi | 78% | 2877 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 46,427 psi | 70% | 2848 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 80% | 38,421 psi | 58% | 2733 fps | 95.4% |
| Alliant Reloder-50 | <<locked>> | 84% | 39,131 psi | 59% | 2736 fps | 95.1% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 49,617 psi | 74% | 2881 fps | 98.8% |
| Bofors RP15 | <<locked>> | 80% | 49,908 psi | 75% | 2910 fps | 100% |
| Bofors RP30 | <<locked>> | 80% | 43,468 psi | 65% | 2805 fps | 99.6% |
| Bofors RP5 | <<locked>> | 80% | 53,476 psi | 80% | 2972 fps | 100% |
| Hodgdon H1000 | <<locked>> | 80% | 43,656 psi | 65% | 2805 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 80% | 54,940 psi | 82% | 2963 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 80% | 53,882 psi | 81% | 2949 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 80% | 46,035 psi | 69% | 2930 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,747 psi | 43% | 1749 fps | 100% |
| Hodgdon US 869 | <<locked>> | 96% | 54,505 psi | 82% | 2995 fps | 95.6% |
| IMR 4955 Enduron | <<locked>> | 80% | 54,795 psi | 82% | 2936 fps | 100% |
| IMR 7828 SSC | <<locked>> | 80% | 51,721 psi | 78% | 2963 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 82% | 47,195 psi | 71% | 2782 fps | 95.2% |
| IMR 8133 Enduron | <<locked>> | 80% | 34,795 psi | 52% | 2625 fps | 97.6% |
| Lovex D100 | <<locked>> | 88% | 51,503 psi | 77% | 2890 fps | 95.4% |
| Lovex S071 | <<locked>> | 80% | 46,064 psi | 69% | 2756 fps | 100% |
| Norma 217 | <<locked>> | 80% | 35,549 psi | 53% | 2654 fps | 99.4% |
| Ramshot Grand | <<locked>> | 80% | 53,084 psi | 80% | 2986 fps | 100% |
| Ramshot LRT | 99.1 gr | 92% | 53,287 psi | 80% | 3031 fps | 95.5% |
| Ramshot Magnum | <<locked>> | 80% | 47,993 psi | 72% | 2851 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,559 psi | 44% | 1791 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 45,963 psi | 69% | 2904 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 42,119 psi | 63% | 2805 fps | 98.6% |
| Shooters World 50 BMG | <<locked>> | 88% | 51,503 psi | 77% | 2890 fps | 95.4% |
| SNPE Vectan SP 13 | <<locked>> | 90% | 42,308 psi | 63% | 2753 fps | 95.9% |
| Vihtavuori 20N29 | <<locked>> | 96% | 45,832 psi | 69% | 2841 fps | 95.3% |
| Vihtavuori 24N41 | <<locked>> | 94% | 55,013 psi | 82% | 3002 fps | 95.7% |
| Vihtavuori N165 | <<locked>> | 80% | 50,502 psi | 76% | 2844 fps | 100% |
| Vihtavuori N170 | <<locked>> | 80% | 43,656 psi | 65% | 2753 fps | 95.8% |
| Vihtavuori N565 | <<locked>> | 80% | 47,892 psi | 72% | 2877 fps | 99.7% |
| Vihtavuori N568 | <<locked>> | 80% | 42,931 psi | 64% | 2818 fps | 98.3% |
| Vihtavuori N570 | 84.6 gr | 80% | 41,133 psi | 62% | 2812 fps | 95.9% |
| Winchester StaBALL HD | <<locked>> | 80% | 53,592 psi | 80% | 2969 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 53,200 psi | 80% | 2900 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 46 powders for 7.21 Firebird loaded with the .284 | 168gr | Berger VLD Hunting. ADI AR 2218 delivers the highest muzzle velocity at 3,179 fps; across all powders the maximum-charge window runs from 1,952 fps to 3,179 fps. Accurate 8700 gives the best case fill at 100 %, and 46 of the 46 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 168.0 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, Ramshot LRT, Vihtavuori N570 rank at the top here: for 7.21 Firebird with the .284 | 168gr | Berger VLD Hunting 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.