Load Specifications
Load data in caliber .255 GS with .257 | 115gr | Frontier PH HPBT bullet and 101 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 70, Hodgdon Superformance and Alliant Reloder-17.
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 2495 | <<locked>> | 84% | 55,317 psi | 87% | 2858 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 57,174 psi | 90% | 2927 fps | 98.4% |
| Accurate 3100ᴾ | <<locked>> | 100% | 50,082 psi | 78% | 2897 fps | 98.8% |
| Accurate 4064 | <<locked>> | 86% | 55,637 psi | 87% | 2913 fps | 100% |
| Accurate 4350 | <<locked>> | 94% | 56,231 psi | 88% | 3018 fps | 100% |
| ADI AR 2206H | <<locked>> | 82% | 54,781 psi | 86% | 2940 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 56,173 psi | 88% | 2949 fps | 100% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 57,580 psi | 90% | 3061 fps | 97.9% |
| ADI Benchmark 8208 | <<locked>> | 82% | 56,971 psi | 89% | 2936 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 55,056 psi | 86% | 3068 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 88% | 56,507 psi | 89% | 2966 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 86% | 57,145 psi | 90% | 2995 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 96% | 56,710 psi | 89% | 3071 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 90% | 54,549 psi | 85% | 3048 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 56,347 psi | 88% | 3041 fps | 97.8% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 50,053 psi | 78% | 2979 fps | 96.7% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 47,021 psi | 74% | 2920 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 41,321 psi | 65% | 2831 fps | 97.8% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 53,867 psi | 84% | 3117 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 54,824 psi | 86% | 2959 fps | 100% |
| Bofors RP3 | <<locked>> | 86% | 53,824 psi | 84% | 2933 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 50,053 psi | 78% | 2979 fps | 96.7% |
| Bofors RP7 | <<locked>> | 92% | 56,913 psi | 89% | 2966 fps | 98.6% |
| Hodgdon BL-C2 | <<locked>> | 82% | 56,985 psi | 89% | 2969 fps | 100% |
| Hodgdon H380 | <<locked>> | 86% | 54,447 psi | 85% | 2949 fps | 99.8% |
| Hodgdon H414 | <<locked>> | 92% | 54,897 psi | 86% | 3012 fps | 98.8% |
| Hodgdon H4350 | <<locked>> | 90% | 55,013 psi | 86% | 2972 fps | 97.8% |
| Hodgdon H4895 | <<locked>> | 82% | 55,361 psi | 87% | 2949 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 98% | 57,130 psi | 90% | 2992 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 55,477 psi | 87% | 2986 fps | 100% |
| Hodgdon Superformance | <<locked>> | 92% | 54,940 psi | 86% | 3048 fps | 98.6% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,085 psi | 57% | 1834 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 56,536 psi | 89% | 2953 fps | 100% |
| IMR 3031 | <<locked>> | 82% | 55,912 psi | 88% | 2930 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 55,593 psi | 87% | 2930 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 55,013 psi | 86% | 2910 fps | 98.7% |
| IMR 4350 | <<locked>> | 94% | 54,157 psi | 85% | 2940 fps | 98.3% |
| IMR 4451 Enduron | <<locked>> | 90% | 55,143 psi | 86% | 2940 fps | 98.7% |
| IMR 4831 | <<locked>> | 96% | 56,623 psi | 89% | 3009 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 55,071 psi | 86% | 2972 fps | 100% |
| IMR 4955 Enduronᴾ | <<locked>> | 100% | 57,058 psi | 89% | 2982 fps | 96.1% |
| IMR 8208 XBR | <<locked>> | 82% | 56,971 psi | 89% | 2936 fps | 100% |
| Lovex D073.6 | <<locked>> | 82% | 55,216 psi | 87% | 2917 fps | 100% |
| Lovex S060 | <<locked>> | 84% | 57,276 psi | 90% | 2917 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 55,709 psi | 87% | 2923 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 55,259 psi | 87% | 2940 fps | 99.5% |
| Lovex S070 | <<locked>> | 94% | 56,434 psi | 88% | 2979 fps | 99.1% |
| Lovex S071ᴾ | <<locked>> | 100% | 41,684 psi | 65% | 2743 fps | 97.1% |
| Norma 201 | <<locked>> | 84% | 57,029 psi | 89% | 2933 fps | 100% |
| Norma 202 | <<locked>> | 82% | 54,447 psi | 85% | 2884 fps | 100% |
| Norma 203B | <<locked>> | 86% | 56,391 psi | 88% | 2982 fps | 100% |
| Norma 204 | <<locked>> | 94% | 55,158 psi | 86% | 2999 fps | 97.3% |
| Norma MRPᴾ | <<locked>> | 100% | 52,881 psi | 83% | 3068 fps | 98.6% |
| Norma URP | <<locked>> | 94% | 54,940 psi | 86% | 3002 fps | 99.9% |
| Ramshot Big Game | <<locked>> | 86% | 57,130 psi | 90% | 3005 fps | 100% |
| Ramshot Hunter | <<locked>> | 96% | 57,392 psi | 90% | 3058 fps | 99.6% |
| Ramshot TAC | <<locked>> | 82% | 57,334 psi | 90% | 2966 fps | 99.7% |
| Ramshot Wild Boar | <<locked>> | 82% | 57,450 psi | 90% | 2982 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,898 psi | 58% | 1880 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 54,476 psi | 85% | 2930 fps | 99.1% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 54,273 psi | 85% | 3009 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 53,940 psi | 85% | 3038 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 56,159 psi | 88% | 3041 fps | 99.9% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 54,708 psi | 86% | 3068 fps | 99.9% |
| Rottweil R 902 | <<locked>> | 84% | 54,259 psi | 85% | 2884 fps | 100% |
| Rottweil R 903 | <<locked>> | 90% | 57,667 psi | 90% | 2982 fps | 100% |
| Rottweil R 904 | <<locked>> | 98% | 55,448 psi | 87% | 2969 fps | 96.4% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 55,782 psi | 87% | 3028 fps | 97.8% |
| Rottweil R 907 | <<locked>> | 92% | 56,913 psi | 89% | 2966 fps | 98.6% |
| Shooters World Long Rifle | <<locked>> | 92% | 55,259 psi | 87% | 2940 fps | 99.5% |
| Shooters World Match Rifle | <<locked>> | 82% | 55,216 psi | 87% | 2917 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 55,709 psi | 87% | 2923 fps | 100% |
| Shooters World SW4350 | <<locked>> | 94% | 56,434 psi | 88% | 2979 fps | 99.1% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 55,535 psi | 87% | 2989 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 56,289 psi | 88% | 2949 fps | 99.8% |
| SNPE Vectan SP 9 | <<locked>> | 84% | 56,782 psi | 89% | 2963 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 54,679 psi | 86% | 2818 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 55,550 psi | 87% | 2822 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 55,071 psi | 86% | 2890 fps | 98.7% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 55,274 psi | 87% | 3025 fps | 97.7% |
| Somchem S335 | <<locked>> | 84% | 57,580 psi | 90% | 2861 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 55,811 psi | 87% | 2933 fps | 100% |
| Somchem S355 | <<locked>> | 90% | 57,537 psi | 90% | 2976 fps | 100% |
| Somchem S361 | <<locked>> | 98% | 57,711 psi | 90% | 2966 fps | 96% |
| Somchem S365 | <<locked>> | 96% | 53,983 psi | 85% | 3005 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 56,405 psi | 88% | 3002 fps | 98.6% |
| Vihtavuori N133 | <<locked>> | 82% | 55,129 psi | 86% | 2802 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 54,360 psi | 85% | 2844 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 54,897 psi | 86% | 2864 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 55,463 psi | 87% | 2900 fps | 100% |
| Vihtavuori N160 | <<locked>> | 94% | 57,203 psi | 90% | 2995 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 48,472 psi | 76% | 2858 fps | 96.8% |
| Vihtavuori N530 | <<locked>> | 82% | 57,682 psi | 90% | 2940 fps | 100% |
| Vihtavuori N540 | <<locked>> | 86% | 56,579 psi | 89% | 2907 fps | 100% |
| Vihtavuori N550 | <<locked>> | 94% | 56,144 psi | 88% | 2999 fps | 99.9% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 52,576 psi | 82% | 2999 fps | 100% |
| Winchester 6.5 StaBALL | <<locked>> | 94% | 57,058 psi | 89% | 2963 fps | 100% |
| Winchester 760 | <<locked>> | 92% | 55,230 psi | 87% | 3018 fps | 98.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 42,540 psi | 67% | 2966 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 84% | 57,232 psi | 90% | 2976 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 52,939 psi | 83% | 2936 fps | 97% |
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 2495 | <<locked>> | 80% | 48,849 psi | 77% | 2766 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 46,876 psi | 73% | 2753 fps | 96.5% |
| Accurate 3100 | <<locked>> | 90% | 35,665 psi | 56% | 2612 fps | 95.2% |
| Accurate 4064 | <<locked>> | 80% | 46,224 psi | 72% | 2769 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 34,635 psi | 54% | 2605 fps | 96.7% |
| ADI AR 2206H | <<locked>> | 80% | 51,430 psi | 81% | 2887 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 43,671 psi | 68% | 2733 fps | 99.2% |
| ADI AR 2209 | <<locked>> | 94% | 47,036 psi | 74% | 2874 fps | 95.6% |
| ADI Benchmark 8208 | <<locked>> | 80% | 53,534 psi | 84% | 2887 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 48,008 psi | 75% | 2949 fps | 99.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 44,150 psi | 69% | 2762 fps | 99.9% |
| Alliant Reloder-15 | <<locked>> | 80% | 47,021 psi | 74% | 2828 fps | 99.7% |
| Alliant Reloder-16 | <<locked>> | 80% | 34,258 psi | 54% | 2621 fps | 96.8% |
| Alliant Reloder-17 | 42.4 gr | 80% | 38,522 psi | 60% | 2749 fps | 99.3% |
| Alliant Reloder-19 | <<locked>> | 94% | 46,572 psi | 73% | 2867 fps | 95.7% |
| Alliant Reloder-22 | <<locked>> | 98% | 46,862 psi | 73% | 2920 fps | 95.9% |
| Alliant Reloder-23 | <<locked>> | 84% | 28,282 psi | 44% | 2470 fps | 95.8% |
| Alliant Reloder-25 | <<locked>> | 96% | 36,463 psi | 57% | 2710 fps | 96% |
| Alliant Reloder-26 | <<locked>> | 86% | 32,474 psi | 51% | 2651 fps | 95.2% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 51,198 psi | 80% | 2900 fps | 99.8% |
| Bofors RP3 | <<locked>> | 80% | 44,309 psi | 69% | 2772 fps | 99.9% |
| Bofors RP5 | <<locked>> | 98% | 46,862 psi | 73% | 2920 fps | 95.9% |
| Bofors RP7 | <<locked>> | 82% | 41,785 psi | 65% | 2690 fps | 95.4% |
| Hodgdon BL-C2 | <<locked>> | 80% | 53,534 psi | 84% | 2917 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 44,672 psi | 70% | 2776 fps | 98.7% |
| Hodgdon H414 | <<locked>> | 82% | 39,262 psi | 62% | 2713 fps | 95.3% |
| Hodgdon H4350 | <<locked>> | 84% | 45,295 psi | 71% | 2795 fps | 95.6% |
| Hodgdon H4895 | <<locked>> | 80% | 52,025 psi | 82% | 2897 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 31,691 psi | 50% | 2513 fps | 97.5% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 48,515 psi | 76% | 2874 fps | 100% |
| Hodgdon Superformance | 47.1 gr | 84% | 41,379 psi | 65% | 2789 fps | 95.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,919 psi | 42% | 1640 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 49,835 psi | 78% | 2848 fps | 100% |
| IMR 3031 | <<locked>> | 80% | 52,634 psi | 82% | 2881 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 45,919 psi | 72% | 2766 fps | 99.6% |
| IMR 4166 Enduron | <<locked>> | 80% | 48,283 psi | 76% | 2795 fps | 97.6% |
| IMR 4350 | <<locked>> | 86% | 42,206 psi | 66% | 2720 fps | 95.6% |
| IMR 4451 Enduron | <<locked>> | 80% | 40,466 psi | 63% | 2661 fps | 95.5% |
| IMR 4831 | <<locked>> | 80% | 33,605 psi | 53% | 2566 fps | 96.4% |
| IMR 4895 | <<locked>> | 80% | 48,225 psi | 76% | 2858 fps | 99.9% |
| IMR 4955 Enduron | <<locked>> | 98% | 53,592 psi | 84% | 2927 fps | 95.3% |
| IMR 8208 XBR | <<locked>> | 80% | 53,534 psi | 84% | 2887 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 51,764 psi | 81% | 2864 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 50,618 psi | 79% | 2812 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 46,137 psi | 72% | 2769 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 38,232 psi | 60% | 2618 fps | 96.4% |
| Lovex S070 | <<locked>> | 82% | 38,754 psi | 61% | 2648 fps | 95.3% |
| Lovex S071 | <<locked>> | 96% | 36,651 psi | 57% | 2635 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 50,589 psi | 79% | 2835 fps | 100% |
| Norma 202 | <<locked>> | 80% | 51,097 psi | 80% | 2835 fps | 100% |
| Norma 203B | <<locked>> | 80% | 46,398 psi | 73% | 2815 fps | 99.8% |
| Norma 204 | <<locked>> | 90% | 48,080 psi | 75% | 2874 fps | 95.8% |
| Norma MRP | <<locked>> | 92% | 40,205 psi | 63% | 2808 fps | 95.4% |
| Norma URP | <<locked>> | 80% | 34,766 psi | 54% | 2605 fps | 96.6% |
| Ramshot Big Game | <<locked>> | 80% | 46,659 psi | 73% | 2835 fps | 99.8% |
| Ramshot Hunter | <<locked>> | 82% | 36,042 psi | 56% | 2648 fps | 95.1% |
| Ramshot TAC | <<locked>> | 80% | 53,693 psi | 84% | 2910 fps | 99.5% |
| Ramshot Wild Boar | <<locked>> | 80% | 53,664 psi | 84% | 2927 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,470 psi | 43% | 1680 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 44,947 psi | 70% | 2759 fps | 97.5% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 50,488 psi | 79% | 2946 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 40,930 psi | 64% | 2812 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 34,461 psi | 54% | 2625 fps | 96.2% |
| ReloadSwiss RS 70 | 43.1 gr | 80% | 33,866 psi | 53% | 2625 fps | 95.3% |
| Rottweil R 902 | <<locked>> | 80% | 48,080 psi | 75% | 2785 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 41,626 psi | 65% | 2713 fps | 99.7% |
| Rottweil R 904 | <<locked>> | 96% | 51,996 psi | 81% | 2910 fps | 95.6% |
| Rottweil R 905 | <<locked>> | 94% | 45,411 psi | 71% | 2848 fps | 95.5% |
| Rottweil R 907 | <<locked>> | 82% | 41,785 psi | 65% | 2690 fps | 95.4% |
| Shooters World Long Rifle | <<locked>> | 80% | 38,232 psi | 60% | 2618 fps | 96.4% |
| Shooters World Match Rifle | <<locked>> | 80% | 51,764 psi | 81% | 2864 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 46,137 psi | 72% | 2769 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 38,754 psi | 61% | 2648 fps | 95.3% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 42,525 psi | 67% | 2762 fps | 99.4% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 52,533 psi | 82% | 2887 fps | 99.6% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 49,864 psi | 78% | 2854 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 51,227 psi | 80% | 2766 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 43,163 psi | 68% | 2631 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 39,740 psi | 62% | 2608 fps | 95.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 44,976 psi | 70% | 2841 fps | 95.4% |
| Somchem S335 | <<locked>> | 80% | 51,256 psi | 80% | 2772 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 52,112 psi | 82% | 2877 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 42,192 psi | 66% | 2717 fps | 99.6% |
| Somchem S361 | <<locked>> | 96% | 53,911 psi | 84% | 2904 fps | 95.1% |
| Somchem S365 | <<locked>> | 80% | 31,212 psi | 49% | 2559 fps | 98.6% |
| Somchem S385 | <<locked>> | 90% | 40,654 psi | 64% | 2720 fps | 95% |
| Vihtavuori N133 | <<locked>> | 80% | 51,735 psi | 81% | 2753 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 47,993 psi | 75% | 2753 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 48,414 psi | 76% | 2766 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 40,147 psi | 63% | 2644 fps | 99.9% |
| Vihtavuori N160 | <<locked>> | 80% | 36,027 psi | 56% | 2605 fps | 97% |
| Vihtavuori N165 | <<locked>> | 96% | 42,525 psi | 67% | 2746 fps | 95.1% |
| Vihtavuori N530 | <<locked>> | 80% | 54,099 psi | 85% | 2887 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 46,688 psi | 73% | 2756 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 35,607 psi | 56% | 2608 fps | 96.6% |
| Vihtavuori N555 | <<locked>> | 82% | 28,935 psi | 45% | 2493 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 35,433 psi | 56% | 2579 fps | 98.8% |
| Winchester 760 | <<locked>> | 82% | 39,508 psi | 62% | 2720 fps | 95.4% |
| Winchester StaBALL HD | <<locked>> | 86% | 26,745 psi | 42% | 2497 fps | 95.4% |
| Winchester StaBALL Match | <<locked>> | 80% | 49,850 psi | 78% | 2864 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 45,934 psi | 72% | 2815 fps | 95.3% |
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 114 powders for .255 GS loaded with the .257 | 115gr | Frontier PH HPBT. Alliant Reloder-26 delivers the highest muzzle velocity at 3,117 fps; across all powders the maximum-charge window runs from 1,834 fps to 3,117 fps. Accurate 3100 gives the best case fill at 100 %, and 114 of the 114 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 115.0 gr projectile in 0.257" calls for a 1:9.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate MAGPRO, ADI AR 2209 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. ReloadSwiss RS 70, Hodgdon Superformance, Alliant Reloder-17 rank at the top here: for .255 GS with the .257 | 115gr | Frontier PH HPBT they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate MAGPRO, Hodgdon H1000, Hodgdon Retumbo burn incompletely and react more sensitively to barrel length and temperature. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.