Load Specifications
Load data in caliber .270 WSM with .277 | 156gr | Sako Hammerhead bullet and 70 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 Accurate MAGPRO.
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: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 90% | 55,172 psi | 86% | 2795 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 56,115 psi | 88% | 2818 fps | 100% |
| Accurate MAGPRO | <<locked>> | 90% | 56,028 psi | 88% | 2933 fps | 98.2% |
| ADI AR 2209 | <<locked>> | 88% | 55,201 psi | 87% | 2861 fps | 99.5% |
| ADI AR 2213 | <<locked>> | 92% | 56,405 psi | 88% | 2920 fps | 99% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 54,694 psi | 86% | 2890 fps | 99.1% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 49,734 psi | 78% | 2867 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 55,535 psi | 87% | 2858 fps | 99.5% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 55,535 psi | 87% | 2858 fps | 99.5% |
| Alliant Reloder-16 | <<locked>> | 84% | 55,521 psi | 87% | 2861 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 54,955 psi | 86% | 2851 fps | 99.5% |
| Alliant Reloder-22 | <<locked>> | 92% | 57,145 psi | 90% | 2927 fps | 99.7% |
| Alliant Reloder-23 | <<locked>> | 92% | 55,172 psi | 86% | 2844 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 57,653 psi | 90% | 2956 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 55,550 psi | 87% | 2936 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 57,450 psi | 90% | 2874 fps | 96.8% |
| Bofors RP15 | <<locked>> | 94% | 56,362 psi | 88% | 2910 fps | 99.6% |
| Bofors RP30 | <<locked>> | 98% | 54,505 psi | 85% | 2917 fps | 99.2% |
| Bofors RP5 | <<locked>> | 92% | 57,145 psi | 90% | 2927 fps | 99.7% |
| Bofors RP7 | <<locked>> | 82% | 56,971 psi | 89% | 2802 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 98% | 56,101 psi | 88% | 2913 fps | 99.5% |
| Hodgdon H414 | <<locked>> | 82% | 56,275 psi | 88% | 2858 fps | 100% |
| Hodgdon H4831 | <<locked>> | 90% | 56,434 psi | 88% | 2861 fps | 98.5% |
| Hodgdon H4831 SC | <<locked>> | 90% | 55,477 psi | 87% | 2844 fps | 98.4% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 56,173 psi | 88% | 2785 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 56,579 psi | 89% | 3031 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 56,246 psi | 88% | 2890 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,826 psi | 59% | 1778 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 54,766 psi | 86% | 2789 fps | 99.8% |
| IMR 4451 Enduron | <<locked>> | 82% | 57,508 psi | 90% | 2815 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 55,883 psi | 88% | 2805 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 57,188 psi | 90% | 2841 fps | 98.7% |
| IMR 7828 SSC | <<locked>> | 92% | 54,650 psi | 86% | 2904 fps | 98.9% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 45,788 psi | 72% | 2785 fps | 97.6% |
| Lovex S065 | <<locked>> | 82% | 55,941 psi | 88% | 2776 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 57,595 psi | 90% | 2825 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 56,637 psi | 89% | 2818 fps | 100% |
| Norma 204 | <<locked>> | 84% | 55,767 psi | 87% | 2844 fps | 99.4% |
| Norma 217ᴾ | <<locked>> | 100% | 46,166 psi | 72% | 2815 fps | 99.4% |
| Norma MRP | <<locked>> | 90% | 57,014 psi | 89% | 2946 fps | 100% |
| Norma URP | <<locked>> | 84% | 56,884 psi | 89% | 2841 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 55,477 psi | 87% | 2927 fps | 99.2% |
| Ramshot Hunter | <<locked>> | 84% | 55,709 psi | 87% | 2851 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 54,085 psi | 85% | 2864 fps | 99.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,711 psi | 61% | 1821 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 55,332 psi | 87% | 2835 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 56,449 psi | 88% | 2907 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 57,305 psi | 90% | 3028 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 56,855 psi | 89% | 2992 fps | 98.6% |
| Rottweil R 904 | <<locked>> | 88% | 56,347 psi | 88% | 2828 fps | 99% |
| Rottweil R 905 | <<locked>> | 88% | 55,013 psi | 86% | 2848 fps | 99.5% |
| Rottweil R 907 | <<locked>> | 82% | 56,971 psi | 89% | 2802 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 82% | 55,941 psi | 88% | 2776 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 57,595 psi | 90% | 2825 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 54,897 psi | 86% | 2730 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 54,578 psi | 86% | 2844 fps | 99.5% |
| Somchem S361 | <<locked>> | 88% | 57,740 psi | 90% | 2822 fps | 98.6% |
| Somchem S365 | <<locked>> | 84% | 54,389 psi | 85% | 2802 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 55,637 psi | 87% | 2822 fps | 99.8% |
| Vihtavuori N160 | <<locked>> | 82% | 55,027 psi | 86% | 2782 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 54,940 psi | 86% | 2802 fps | 99.7% |
| Vihtavuori N550 | <<locked>> | 82% | 54,592 psi | 86% | 2792 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 54,795 psi | 86% | 2831 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 56,565 psi | 89% | 2940 fps | 98.8% |
| Vihtavuori N565 | <<locked>> | 96% | 57,551 psi | 90% | 2933 fps | 99% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 57,551 psi | 90% | 2989 fps | 98.2% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 57,450 psi | 90% | 2782 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 56,463 psi | 88% | 2861 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 56,739 psi | 89% | 2986 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 54,897 psi | 86% | 2812 fps | 99.4% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 80% | 41,147 psi | 64% | 2556 fps | 99.1% |
| Accurate 4350 | <<locked>> | 80% | 52,823 psi | 83% | 2772 fps | 100% |
| Accurate MAGPRO | 58.1 gr | 82% | 43,424 psi | 68% | 2700 fps | 95.3% |
| ADI AR 2209 | <<locked>> | 80% | 43,294 psi | 68% | 2644 fps | 97.6% |
| ADI AR 2213 | <<locked>> | 82% | 41,597 psi | 65% | 2641 fps | 95.8% |
| ADI AR 2217 | <<locked>> | 90% | 40,495 psi | 63% | 2615 fps | 95.7% |
| ADI AR 2225 | <<locked>> | 84% | 31,401 psi | 49% | 2434 fps | 95.3% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 43,874 psi | 69% | 2651 fps | 97.8% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 43,874 psi | 69% | 2651 fps | 97.8% |
| Alliant Reloder-16 | <<locked>> | 80% | 49,182 psi | 77% | 2762 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 43,468 psi | 68% | 2644 fps | 97.7% |
| Alliant Reloder-22 | <<locked>> | 80% | 39,653 psi | 62% | 2602 fps | 96.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 38,609 psi | 61% | 2566 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 34,011 psi | 53% | 2497 fps | 98.3% |
| Alliant Reloder-26 | <<locked>> | 80% | 42,525 psi | 67% | 2717 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 51,242 psi | 80% | 2766 fps | 95.3% |
| Bofors RP15 | <<locked>> | 80% | 37,362 psi | 59% | 2546 fps | 95.9% |
| Bofors RP30 | <<locked>> | 86% | 37,942 psi | 59% | 2595 fps | 95.4% |
| Bofors RP5 | <<locked>> | 80% | 39,653 psi | 62% | 2602 fps | 96.8% |
| Bofors RP7 | <<locked>> | 80% | 53,824 psi | 84% | 2753 fps | 99.7% |
| Hodgdon H1000 | <<locked>> | 84% | 36,651 psi | 57% | 2526 fps | 95% |
| Hodgdon H414 | <<locked>> | 80% | 53,127 psi | 83% | 2808 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 80% | 41,510 psi | 65% | 2589 fps | 95.2% |
| Hodgdon H4831 SC | <<locked>> | 82% | 43,424 psi | 68% | 2628 fps | 95.7% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 47,021 psi | 74% | 2648 fps | 100% |
| Hodgdon Retumbo | 55 gr | 82% | 35,230 psi | 55% | 2575 fps | 95.8% |
| Hodgdon Superformance | <<locked>> | 80% | 52,750 psi | 83% | 2838 fps | 99.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,529 psi | 45% | 1588 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 48,921 psi | 77% | 2690 fps | 99.3% |
| IMR 4451 Enduron | <<locked>> | 80% | 54,317 psi | 85% | 2766 fps | 99.9% |
| IMR 4831 | <<locked>> | 80% | 49,603 psi | 78% | 2710 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 42,917 psi | 67% | 2582 fps | 95.8% |
| IMR 7828 SSC | <<locked>> | 82% | 40,263 psi | 63% | 2621 fps | 95.5% |
| IMR 8133 Enduron | <<locked>> | 94% | 38,392 psi | 60% | 2625 fps | 95.3% |
| Lovex S065 | <<locked>> | 80% | 52,910 psi | 83% | 2730 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 51,474 psi | 81% | 2726 fps | 99.8% |
| Lovex S071 | <<locked>> | 80% | 36,245 psi | 57% | 2448 fps | 98.2% |
| Norma 204 | <<locked>> | 80% | 49,168 psi | 77% | 2733 fps | 98.6% |
| Norma 217 | <<locked>> | 88% | 32,634 psi | 51% | 2500 fps | 95.4% |
| Norma MRP | <<locked>> | 80% | 41,640 psi | 65% | 2671 fps | 98.6% |
| Norma URP | <<locked>> | 80% | 50,647 psi | 79% | 2746 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 40,205 psi | 63% | 2635 fps | 95.9% |
| Ramshot Hunter | <<locked>> | 80% | 49,269 psi | 77% | 2746 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 80% | 34,316 psi | 54% | 2474 fps | 95.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,182 psi | 46% | 1627 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 51,996 psi | 81% | 2785 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 49,371 psi | 77% | 2799 fps | 100% |
| ReloadSwiss RS 76 | 57.4 gr | 80% | 32,445 psi | 51% | 2497 fps | 95.7% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 43,482 psi | 68% | 2749 fps | 95.5% |
| Rottweil R 904 | <<locked>> | 80% | 44,527 psi | 70% | 2621 fps | 96.8% |
| Rottweil R 905 | <<locked>> | 80% | 43,279 psi | 68% | 2638 fps | 97.8% |
| Rottweil R 907 | <<locked>> | 80% | 53,824 psi | 84% | 2753 fps | 99.7% |
| Shooters World Long Rifle | <<locked>> | 80% | 52,910 psi | 83% | 2730 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 51,474 psi | 81% | 2726 fps | 99.8% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 51,851 psi | 81% | 2680 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 42,917 psi | 67% | 2631 fps | 97.7% |
| Somchem S361 | <<locked>> | 80% | 45,368 psi | 71% | 2608 fps | 96.2% |
| Somchem S365 | <<locked>> | 80% | 48,240 psi | 76% | 2710 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 43,990 psi | 69% | 2618 fps | 98.6% |
| Vihtavuori N160 | <<locked>> | 80% | 51,953 psi | 81% | 2733 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 38,566 psi | 60% | 2500 fps | 97% |
| Vihtavuori N550 | <<locked>> | 80% | 51,387 psi | 81% | 2740 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 43,497 psi | 68% | 2641 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 41,481 psi | 65% | 2657 fps | 95.4% |
| Vihtavuori N565 | <<locked>> | 84% | 40,118 psi | 63% | 2612 fps | 95.3% |
| Vihtavuori N568 | <<locked>> | 92% | 44,599 psi | 70% | 2756 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 50,560 psi | 79% | 2687 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 53,127 psi | 83% | 2808 fps | 99.9% |
| Winchester StaBALL HD | <<locked>> | 80% | 35,128 psi | 55% | 2618 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 40,306 psi | 63% | 2546 fps | 96.9% |
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 70 powders for .270 WSM loaded with the .277 | 156gr | Sako Hammerhead. Hodgdon Retumbo delivers the highest muzzle velocity at 3,031 fps; across all powders the maximum-charge window runs from 1,778 fps to 3,031 fps. ADI AR 2217 gives the best case fill at 100 %, and 70 of the 70 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 156.0 gr projectile in 0.277" calls for a 1:12.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, 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. Hodgdon Retumbo, ReloadSwiss RS 76, Accurate MAGPRO rank at the top here: for .270 WSM with the .277 | 156gr | Sako Hammerhead 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.