Load Specifications
Load data in caliber 7 x 66 SE v. Hofe with .284 | 170gr | Sierra RN Prohunter bullet and 71 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon Retumbo, ReloadSwiss RS 76 and ReloadSwiss RS 80.
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: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 90% | 55,506 psi | 87% | 2848 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 56,246 psi | 88% | 2867 fps | 100% |
| Accurate High Country | <<locked>> | 88% | 57,130 psi | 90% | 3005 fps | 99.8% |
| Accurate MAGPRO | <<locked>> | 88% | 54,070 psi | 85% | 2949 fps | 99% |
| ADI AR 2209 | <<locked>> | 88% | 56,840 psi | 89% | 2933 fps | 100% |
| ADI AR 2213 | <<locked>> | 90% | 54,969 psi | 86% | 2946 fps | 99.7% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 57,029 psi | 89% | 2976 fps | 99.9% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 49,342 psi | 77% | 2943 fps | 96.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 51,314 psi | 80% | 2940 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 57,174 psi | 90% | 2920 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 56,492 psi | 89% | 2923 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 90% | 55,303 psi | 87% | 2943 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 92% | 57,058 psi | 89% | 2904 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 56,739 psi | 89% | 2972 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 57,624 psi | 90% | 2995 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 54,186 psi | 85% | 3005 fps | 97.7% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 55,898 psi | 88% | 2907 fps | 98% |
| Bofors RP15 | <<locked>> | 92% | 54,520 psi | 85% | 2927 fps | 99.9% |
| Bofors RP30 | <<locked>> | 98% | 56,608 psi | 89% | 2989 fps | 99.9% |
| Bofors RP5 | <<locked>> | 90% | 55,303 psi | 87% | 2943 fps | 100% |
| Bofors RP7 | <<locked>> | 82% | 57,551 psi | 90% | 2864 fps | 100% |
| Hodgdon H1000 | <<locked>> | 96% | 54,621 psi | 86% | 2940 fps | 100% |
| Hodgdon H414 | <<locked>> | 82% | 57,479 psi | 90% | 2920 fps | 100% |
| Hodgdon H4831 | <<locked>> | 88% | 54,534 psi | 85% | 2881 fps | 99.2% |
| Hodgdon H4831 SC | <<locked>> | 90% | 57,145 psi | 90% | 2920 fps | 99.5% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 57,392 psi | 90% | 2838 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 55,622 psi | 87% | 3061 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,565 psi | 59% | 1814 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 56,101 psi | 88% | 2858 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 56,492 psi | 89% | 2858 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 55,158 psi | 86% | 2861 fps | 99.4% |
| IMR 7828 SSC | <<locked>> | 92% | 56,971 psi | 89% | 2986 fps | 99.8% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 46,876 psi | 73% | 2851 fps | 99% |
| Lovex S065 | <<locked>> | 82% | 56,318 psi | 88% | 2828 fps | 100% |
| Lovex S070 | <<locked>> | 82% | 54,781 psi | 86% | 2831 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 56,927 psi | 89% | 2867 fps | 100% |
| Norma 204 | <<locked>> | 84% | 57,043 psi | 89% | 2913 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 47,500 psi | 74% | 2877 fps | 100% |
| Norma MRP | <<locked>> | 88% | 55,376 psi | 87% | 2959 fps | 100% |
| Norma URP | <<locked>> | 82% | 54,505 psi | 85% | 2848 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 54,085 psi | 85% | 2949 fps | 99.8% |
| Ramshot Hunter | <<locked>> | 84% | 56,855 psi | 89% | 2907 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 56,507 psi | 89% | 2940 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,464 psi | 60% | 1857 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 56,246 psi | 88% | 2890 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 54,636 psi | 86% | 2917 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 56,478 psi | 89% | 3054 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 55,680 psi | 87% | 3018 fps | 99.4% |
| Rottweil R 904 | <<locked>> | 88% | 57,609 psi | 90% | 2900 fps | 99.8% |
| Rottweil R 905 | <<locked>> | 88% | 56,188 psi | 88% | 2913 fps | 100% |
| Rottweil R 907 | <<locked>> | 82% | 57,551 psi | 90% | 2864 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 82% | 56,318 psi | 88% | 2828 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 54,781 psi | 86% | 2831 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 55,216 psi | 87% | 2785 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 55,782 psi | 87% | 2910 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 55,506 psi | 87% | 2841 fps | 99.3% |
| Somchem S365 | <<locked>> | 84% | 55,608 psi | 87% | 2851 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 56,695 psi | 89% | 2884 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 56,043 psi | 88% | 2838 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 56,260 psi | 88% | 2867 fps | 100% |
| Vihtavuori N170 | <<locked>> | 96% | 55,027 psi | 86% | 2884 fps | 96.1% |
| Vihtavuori N550 | <<locked>> | 82% | 55,114 psi | 86% | 2841 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 55,492 psi | 87% | 2881 fps | 100% |
| Vihtavuori N560 | <<locked>> | 88% | 54,998 psi | 86% | 2963 fps | 99.4% |
| Vihtavuori N565 | <<locked>> | 94% | 55,274 psi | 87% | 2949 fps | 99.6% |
| Vihtavuori N568 | <<locked>> | 98% | 56,449 psi | 88% | 3018 fps | 99.1% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 57,464 psi | 90% | 3077 fps | 98% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 55,317 psi | 87% | 2789 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 57,740 psi | 90% | 2923 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 56,057 psi | 88% | 2992 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 56,275 psi | 88% | 2881 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 80% | 39,639 psi | 62% | 2579 fps | 99.6% |
| Accurate 4350 | <<locked>> | 80% | 52,489 psi | 82% | 2812 fps | 100% |
| Accurate High Country | <<locked>> | 80% | 43,221 psi | 68% | 2756 fps | 98% |
| Accurate MAGPRO | <<locked>> | 80% | 40,770 psi | 64% | 2697 fps | 96.1% |
| ADI AR 2209 | <<locked>> | 80% | 43,671 psi | 68% | 2707 fps | 98.8% |
| ADI AR 2213 | <<locked>> | 80% | 39,073 psi | 61% | 2644 fps | 96.7% |
| ADI AR 2217 | <<locked>> | 86% | 35,491 psi | 56% | 2559 fps | 95.8% |
| ADI AR 2218 | <<locked>> | 98% | 46,021 psi | 72% | 2874 fps | 95.3% |
| ADI AR 2225 | <<locked>> | 82% | 28,340 psi | 44% | 2408 fps | 95.6% |
| Alliant Reloder-16 | <<locked>> | 80% | 50,212 psi | 79% | 2815 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 43,627 psi | 68% | 2700 fps | 98.8% |
| Alliant Reloder-22 | <<locked>> | 80% | 39,624 psi | 62% | 2651 fps | 98.1% |
| Alliant Reloder-23 | <<locked>> | 80% | 38,406 psi | 60% | 2602 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 33,127 psi | 52% | 2530 fps | 99.1% |
| Alliant Reloder-26 | <<locked>> | 80% | 42,888 psi | 67% | 2759 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 96% | 46,557 psi | 73% | 2867 fps | 95.9% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 46,412 psi | 73% | 2736 fps | 95.9% |
| Bofors RP15 | <<locked>> | 80% | 36,796 psi | 58% | 2585 fps | 97.2% |
| Bofors RP30 | <<locked>> | 82% | 32,837 psi | 51% | 2516 fps | 95% |
| Bofors RP5 | <<locked>> | 80% | 39,624 psi | 62% | 2651 fps | 98.1% |
| Bofors RP7 | <<locked>> | 80% | 54,114 psi | 85% | 2812 fps | 100% |
| Hodgdon H1000 | <<locked>> | 82% | 33,808 psi | 53% | 2516 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 80% | 53,809 psi | 84% | 2864 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 41,597 psi | 65% | 2644 fps | 96.8% |
| Hodgdon H4831 SC | <<locked>> | 80% | 40,886 psi | 64% | 2631 fps | 96.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 47,282 psi | 74% | 2694 fps | 100% |
| Hodgdon Retumbo | 62.3 gr | 80% | 32,401 psi | 51% | 2559 fps | 96.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,210 psi | 44% | 1621 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 49,429 psi | 77% | 2749 fps | 99.9% |
| IMR 4831 | <<locked>> | 80% | 49,617 psi | 78% | 2756 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 43,004 psi | 67% | 2641 fps | 97.3% |
| IMR 7828 SSC | <<locked>> | 80% | 37,768 psi | 59% | 2621 fps | 96.4% |
| IMR 8133 Enduron | <<locked>> | 90% | 33,446 psi | 52% | 2556 fps | 95% |
| Lovex S065 | <<locked>> | 80% | 53,011 psi | 83% | 2782 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 51,314 psi | 80% | 2776 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 34,316 psi | 54% | 2461 fps | 98.7% |
| Norma 204 | <<locked>> | 80% | 49,864 psi | 78% | 2799 fps | 99.6% |
| Norma 217 | <<locked>> | 86% | 29,501 psi | 46% | 2467 fps | 95.6% |
| Norma MRP | <<locked>> | 80% | 41,742 psi | 65% | 2720 fps | 99.4% |
| Norma URP | <<locked>> | 80% | 50,937 psi | 80% | 2792 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 37,536 psi | 59% | 2631 fps | 96.7% |
| Ramshot Hunter | <<locked>> | 80% | 49,864 psi | 78% | 2802 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 33,620 psi | 53% | 2513 fps | 97.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,921 psi | 45% | 1660 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 52,605 psi | 82% | 2835 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 50,981 psi | 80% | 2861 fps | 100% |
| ReloadSwiss RS 76 | 66.6 gr | 80% | 31,343 psi | 49% | 2530 fps | 97.2% |
| ReloadSwiss RS 80 | 73.9 gr | 88% | 38,087 psi | 60% | 2680 fps | 95.4% |
| Rottweil R 904 | <<locked>> | 80% | 44,628 psi | 70% | 2680 fps | 98.2% |
| Rottweil R 905 | <<locked>> | 80% | 43,076 psi | 68% | 2687 fps | 98.9% |
| Rottweil R 907 | <<locked>> | 80% | 54,114 psi | 85% | 2812 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 80% | 53,011 psi | 83% | 2782 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 51,314 psi | 80% | 2776 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 51,924 psi | 81% | 2733 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 42,728 psi | 67% | 2680 fps | 98.8% |
| Somchem S361 | <<locked>> | 80% | 45,600 psi | 71% | 2674 fps | 97.8% |
| Somchem S365 | <<locked>> | 80% | 48,617 psi | 76% | 2749 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 43,642 psi | 68% | 2667 fps | 99.4% |
| Vihtavuori N160 | <<locked>> | 80% | 52,446 psi | 82% | 2785 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 37,956 psi | 59% | 2543 fps | 98.1% |
| Vihtavuori N170 | <<locked>> | 94% | 51,503 psi | 81% | 2825 fps | 95.3% |
| Vihtavuori N550 | <<locked>> | 80% | 51,822 psi | 81% | 2792 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 42,772 psi | 67% | 2674 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 41,640 psi | 65% | 2713 fps | 97% |
| Vihtavuori N565 | <<locked>> | 82% | 36,912 psi | 58% | 2592 fps | 95.7% |
| Vihtavuori N568 | <<locked>> | 88% | 39,436 psi | 62% | 2697 fps | 95.2% |
| Vihtavuori N570 | <<locked>> | 94% | 46,238 psi | 72% | 2877 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 51,619 psi | 81% | 2740 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 53,998 psi | 85% | 2867 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 35,433 psi | 56% | 2648 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 39,972 psi | 63% | 2595 fps | 98.1% |
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 71 powders for 7 x 66 SE v. Hofe loaded with the .284 | 170gr | Sierra RN Prohunter. Vihtavuori N570 delivers the highest muzzle velocity at 3,077 fps; across all powders the maximum-charge window runs from 1,814 fps to 3,077 fps. ADI AR 2217 gives the best case fill at 100 %, and 71 of the 71 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 59–90 %, leaving at least 10 % headroom. The 170.0 gr projectile in 0.284" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2218, ADI AR 2225 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. Hodgdon Retumbo, ReloadSwiss RS 76, ReloadSwiss RS 80 rank at the top here: for 7 x 66 SE v. Hofe with the .284 | 170gr | Sierra RN Prohunter 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.