Load Specifications
Bullet Manufacturer:Hornady
Bullet Weight:117 gr
Bullet Diameter:0.257"
Bullet Length:<<locked>>
Caliber:.255 GS load data
Case Length (l3):2.165"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:62 Grains of Water
Primer Size:Large Rifle (LR)
Barrel Length:24"
Max. allowed Pressure:63,817 psi
Recommended Twist Rate:1:11.0
Load data in caliber .255 GS with .257 | 117gr | Hornady InterLock RN bullet and 100 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 70, Alliant Reloder-16 and Alliant Reloder-26.
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% | 57,624 psi | 90% | 2867 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 55,114 psi | 86% | 2884 fps | 98.4% |
| Accurate 3100ᴾ | <<locked>> | 100% | 52,591 psi | 82% | 2920 fps | 99.3% |
| Accurate 4064 | <<locked>> | 84% | 54,389 psi | 85% | 2874 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 55,042 psi | 86% | 2982 fps | 100% |
| ADI AR 2206H | <<locked>> | 82% | 56,753 psi | 89% | 2953 fps | 100% |
| ADI AR 2208 | <<locked>> | 86% | 54,650 psi | 86% | 2910 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 55,941 psi | 88% | 3018 fps | 98% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 53,693 psi | 84% | 3009 fps | 96.2% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 57,551 psi | 90% | 3091 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 55,419 psi | 87% | 2933 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 55,709 psi | 87% | 2956 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 55,840 psi | 88% | 3038 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 90% | 57,014 psi | 89% | 3061 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 55,245 psi | 87% | 3009 fps | 97.9% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 52,388 psi | 82% | 3005 fps | 97.6% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 49,400 psi | 77% | 2943 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 43,236 psi | 68% | 2861 fps | 98.6% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 56,971 psi | 89% | 3143 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 57,029 psi | 89% | 2976 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 48,124 psi | 75% | 2927 fps | 96.5% |
| Bofors RP3 | <<locked>> | 86% | 56,246 psi | 88% | 2949 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 52,388 psi | 82% | 3005 fps | 97.6% |
| Bofors RP7 | <<locked>> | 90% | 55,564 psi | 87% | 2930 fps | 98.7% |
| Hodgdon H380 | <<locked>> | 86% | 56,753 psi | 89% | 2969 fps | 100% |
| Hodgdon H414 | <<locked>> | 92% | 57,116 psi | 90% | 3031 fps | 99.3% |
| Hodgdon H4350 | <<locked>> | 90% | 57,130 psi | 90% | 2992 fps | 98.4% |
| Hodgdon H4831ᴾ | <<locked>> | 100% | 57,464 psi | 90% | 3012 fps | 96.4% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 56,362 psi | 88% | 2995 fps | 96.2% |
| Hodgdon H4895 | <<locked>> | 82% | 57,435 psi | 90% | 2963 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 56,202 psi | 88% | 2963 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 54,099 psi | 85% | 2946 fps | 100% |
| Hodgdon Superformance | <<locked>> | 90% | 53,519 psi | 84% | 3009 fps | 98.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,405 psi | 57% | 1834 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 55,013 psi | 86% | 2913 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 57,566 psi | 90% | 2943 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 56,739 psi | 89% | 2923 fps | 99.2% |
| IMR 4350 | <<locked>> | 94% | 56,536 psi | 89% | 2966 fps | 98.8% |
| IMR 4451 Enduron | <<locked>> | 90% | 57,188 psi | 90% | 2959 fps | 99.2% |
| IMR 4831 | <<locked>> | 94% | 55,361 psi | 87% | 2969 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 57,130 psi | 90% | 2982 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 55,405 psi | 87% | 2943 fps | 96.2% |
| Lovex D073.6 | <<locked>> | 82% | 57,334 psi | 90% | 2927 fps | 100% |
| Lovex S060 | <<locked>> | 82% | 55,738 psi | 87% | 2877 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 57,725 psi | 90% | 2936 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 57,348 psi | 90% | 2956 fps | 99.8% |
| Lovex S070 | <<locked>> | 92% | 55,143 psi | 86% | 2943 fps | 99.1% |
| Lovex S071ᴾ | <<locked>> | 100% | 43,743 psi | 69% | 2766 fps | 97.9% |
| Norma 201 | <<locked>> | 82% | 55,579 psi | 87% | 2894 fps | 100% |
| Norma 202 | <<locked>> | 82% | 56,173 psi | 88% | 2890 fps | 100% |
| Norma 203B | <<locked>> | 84% | 54,998 psi | 86% | 2943 fps | 100% |
| Norma 204 | <<locked>> | 94% | 57,246 psi | 90% | 3015 fps | 98% |
| Norma MRPᴾ | <<locked>> | 100% | 55,738 psi | 87% | 3094 fps | 99.2% |
| Norma URP | <<locked>> | 94% | 57,305 psi | 90% | 3018 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 55,608 psi | 87% | 2966 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 51,532 psi | 81% | 2995 fps | 96.2% |
| Ramshot Hunter | <<locked>> | 94% | 56,043 psi | 88% | 3018 fps | 99.6% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 45,716 psi | 72% | 2861 fps | 96.7% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,941 psi | 58% | 1877 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 56,579 psi | 89% | 2949 fps | 99.5% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 56,521 psi | 89% | 3022 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 56,811 psi | 89% | 3058 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 54,911 psi | 86% | 3005 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 57,232 psi | 90% | 3091 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 42,192 psi | 66% | 2874 fps | 96.5% |
| Rottweil R 902 | <<locked>> | 84% | 56,246 psi | 88% | 2897 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 56,101 psi | 88% | 2943 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 54,331 psi | 85% | 2936 fps | 96.6% |
| Rottweil R 905 | <<locked>> | 98% | 54,389 psi | 85% | 2992 fps | 97.9% |
| Rottweil R 907 | <<locked>> | 90% | 55,564 psi | 87% | 2930 fps | 98.7% |
| Shooters World Long Rifle | <<locked>> | 92% | 57,348 psi | 90% | 2956 fps | 99.8% |
| Shooters World Match Rifle | <<locked>> | 82% | 57,334 psi | 90% | 2927 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 57,725 psi | 90% | 2936 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 55,143 psi | 86% | 2943 fps | 99.1% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 54,027 psi | 85% | 2949 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 55,259 psi | 87% | 2923 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 56,304 psi | 88% | 2825 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 57,101 psi | 89% | 2825 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 57,087 psi | 89% | 2907 fps | 99.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 53,911 psi | 84% | 2986 fps | 97.8% |
| Somchem S335 | <<locked>> | 82% | 56,072 psi | 88% | 2822 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 56,014 psi | 88% | 2936 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 55,970 psi | 88% | 2927 fps | 96% |
| Somchem S365 | <<locked>> | 96% | 56,550 psi | 89% | 3018 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 55,347 psi | 87% | 2972 fps | 98.7% |
| Vihtavuori N133 | <<locked>> | 82% | 56,840 psi | 89% | 2805 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 56,594 psi | 89% | 2854 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 56,898 psi | 89% | 2871 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 57,696 psi | 90% | 2913 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 55,869 psi | 88% | 2959 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 50,734 psi | 80% | 2881 fps | 97.6% |
| Vihtavuori N540 | <<locked>> | 84% | 55,027 psi | 86% | 2867 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 54,853 psi | 86% | 2963 fps | 99.9% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 55,332 psi | 87% | 3022 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 56,115 psi | 88% | 3084 fps | 96.5% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 55,492 psi | 87% | 2927 fps | 100% |
| Winchester 760 | <<locked>> | 92% | 57,479 psi | 90% | 3038 fps | 99.3% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 44,628 psi | 70% | 2995 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 55,317 psi | 87% | 2930 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 55,303 psi | 87% | 2963 fps | 97.8% |
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% | 50,749 psi | 80% | 2776 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 48,559 psi | 76% | 2772 fps | 97.3% |
| Accurate 3100 | <<locked>> | 88% | 34,954 psi | 55% | 2579 fps | 95.3% |
| Accurate 4064 | <<locked>> | 80% | 48,051 psi | 75% | 2779 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 36,463 psi | 57% | 2631 fps | 97.6% |
| ADI AR 2206H | <<locked>> | 80% | 53,447 psi | 84% | 2904 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 45,455 psi | 71% | 2753 fps | 99.6% |
| ADI AR 2209 | <<locked>> | 92% | 45,948 psi | 72% | 2841 fps | 95.7% |
| ADI AR 2213 | <<locked>> | 98% | 50,357 psi | 79% | 2949 fps | 95.4% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 49,966 psi | 78% | 2966 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 45,730 psi | 72% | 2772 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 48,936 psi | 77% | 2844 fps | 99.9% |
| Alliant Reloder-16 | 40.4 gr | 80% | 35,621 psi | 56% | 2641 fps | 97.6% |
| Alliant Reloder-17 | <<locked>> | 80% | 40,248 psi | 63% | 2769 fps | 99.7% |
| Alliant Reloder-19 | <<locked>> | 90% | 42,844 psi | 67% | 2779 fps | 95% |
| Alliant Reloder-22 | <<locked>> | 94% | 43,018 psi | 67% | 2825 fps | 95.2% |
| Alliant Reloder-23 | <<locked>> | 82% | 27,804 psi | 44% | 2444 fps | 96% |
| Alliant Reloder-25 | <<locked>> | 92% | 33,446 psi | 52% | 2615 fps | 95% |
| Alliant Reloder-26 | 46.8 gr | 84% | 31,821 psi | 50% | 2618 fps | 95.3% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 53,069 psi | 83% | 2913 fps | 100% |
| Bofors RP15 | <<locked>> | 98% | 45,150 psi | 71% | 2867 fps | 95.7% |
| Bofors RP3 | <<locked>> | 80% | 45,948 psi | 72% | 2782 fps | 100% |
| Bofors RP5 | <<locked>> | 94% | 43,018 psi | 67% | 2825 fps | 95.2% |
| Bofors RP7 | <<locked>> | 80% | 40,567 psi | 64% | 2648 fps | 95.4% |
| Hodgdon H380 | <<locked>> | 80% | 46,499 psi | 73% | 2795 fps | 99.2% |
| Hodgdon H414 | <<locked>> | 80% | 38,493 psi | 60% | 2680 fps | 95.4% |
| Hodgdon H4350 | <<locked>> | 82% | 44,193 psi | 69% | 2762 fps | 95.7% |
| Hodgdon H4831 | <<locked>> | 98% | 53,853 psi | 84% | 2956 fps | 95.6% |
| Hodgdon H4831 SC | <<locked>> | 98% | 52,852 psi | 83% | 2936 fps | 95.4% |
| Hodgdon H4895 | <<locked>> | 80% | 54,027 psi | 85% | 2910 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 33,069 psi | 52% | 2533 fps | 98.2% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 50,531 psi | 79% | 2890 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 40,030 psi | 63% | 2743 fps | 95.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,180 psi | 43% | 1640 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 51,445 psi | 81% | 2858 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 47,790 psi | 75% | 2785 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 80% | 50,024 psi | 78% | 2812 fps | 98.2% |
| IMR 4350 | <<locked>> | 84% | 41,191 psi | 65% | 2684 fps | 95.6% |
| IMR 4451 Enduron | <<locked>> | 80% | 42,032 psi | 66% | 2684 fps | 96.4% |
| IMR 4831 | <<locked>> | 80% | 35,056 psi | 55% | 2582 fps | 97.2% |
| IMR 4895 | <<locked>> | 80% | 50,212 psi | 79% | 2874 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 52,170 psi | 82% | 2890 fps | 95.4% |
| Lovex D073.6 | <<locked>> | 80% | 53,519 psi | 84% | 2874 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 52,475 psi | 82% | 2828 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 48,066 psi | 75% | 2785 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 39,610 psi | 62% | 2635 fps | 97.2% |
| Lovex S070 | <<locked>> | 80% | 37,695 psi | 59% | 2608 fps | 95.4% |
| Lovex S071 | <<locked>> | 94% | 36,143 psi | 57% | 2608 fps | 95.8% |
| Norma 201 | <<locked>> | 80% | 52,257 psi | 82% | 2844 fps | 100% |
| Norma 202 | <<locked>> | 80% | 52,808 psi | 83% | 2841 fps | 100% |
| Norma 203B | <<locked>> | 80% | 48,312 psi | 76% | 2831 fps | 100% |
| Norma 204 | <<locked>> | 88% | 46,731 psi | 73% | 2835 fps | 95.8% |
| Norma MRP | <<locked>> | 90% | 39,436 psi | 62% | 2779 fps | 95.5% |
| Norma URP | <<locked>> | 80% | 36,201 psi | 57% | 2625 fps | 97.4% |
| Ramshot Big Game | <<locked>> | 80% | 48,573 psi | 76% | 2854 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 47,892 psi | 75% | 2927 fps | 95.2% |
| Ramshot Hunter | <<locked>> | 80% | 35,114 psi | 55% | 2605 fps | 95.1% |
| Ramshot Magnum | <<locked>> | 98% | 42,496 psi | 67% | 2795 fps | 95.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,485 psi | 43% | 1673 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 46,369 psi | 73% | 2772 fps | 98.1% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 52,649 psi | 83% | 2963 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 42,757 psi | 67% | 2828 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 36,187 psi | 57% | 2648 fps | 97.2% |
| ReloadSwiss RS 70 | 44.2 gr | 80% | 35,244 psi | 55% | 2651 fps | 96.3% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 39,363 psi | 62% | 2802 fps | 95.3% |
| Rottweil R 902 | <<locked>> | 80% | 49,763 psi | 78% | 2795 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 43,265 psi | 68% | 2726 fps | 99.9% |
| Rottweil R 904 | <<locked>> | 92% | 47,659 psi | 75% | 2818 fps | 95% |
| Rottweil R 905 | <<locked>> | 92% | 44,498 psi | 70% | 2815 fps | 95.7% |
| Rottweil R 907 | <<locked>> | 80% | 40,567 psi | 64% | 2648 fps | 95.4% |
| Shooters World Long Rifle | <<locked>> | 80% | 39,610 psi | 62% | 2635 fps | 97.2% |
| Shooters World Match Rifle | <<locked>> | 80% | 53,519 psi | 84% | 2874 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 48,066 psi | 75% | 2785 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 37,695 psi | 59% | 2608 fps | 95.4% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 44,338 psi | 69% | 2782 fps | 99.7% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 51,750 psi | 81% | 2867 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 52,881 psi | 83% | 2776 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 44,672 psi | 70% | 2641 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 38,783 psi | 61% | 2575 fps | 95.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 44,121 psi | 69% | 2808 fps | 95.5% |
| Somchem S335 | <<locked>> | 80% | 52,808 psi | 83% | 2776 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 43,772 psi | 69% | 2730 fps | 99.9% |
| Somchem S361 | <<locked>> | 94% | 52,359 psi | 82% | 2867 fps | 95.2% |
| Somchem S365 | <<locked>> | 80% | 32,837 psi | 51% | 2585 fps | 99.3% |
| Somchem S385 | <<locked>> | 88% | 39,697 psi | 62% | 2680 fps | 95.1% |
| Vihtavuori N133 | <<locked>> | 80% | 53,447 psi | 84% | 2759 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 49,821 psi | 78% | 2759 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 50,024 psi | 78% | 2772 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 41,626 psi | 65% | 2657 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 37,724 psi | 59% | 2628 fps | 97.8% |
| Vihtavuori N165 | <<locked>> | 94% | 41,626 psi | 65% | 2713 fps | 95.3% |
| Vihtavuori N540 | <<locked>> | 80% | 48,457 psi | 76% | 2766 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 37,188 psi | 58% | 2628 fps | 97.4% |
| Vihtavuori N555 | <<locked>> | 80% | 28,601 psi | 45% | 2464 fps | 95.1% |
| Vihtavuori N560 | <<locked>> | 98% | 52,330 psi | 82% | 3018 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 36,811 psi | 58% | 2595 fps | 99.3% |
| Winchester 760 | <<locked>> | 80% | 38,493 psi | 60% | 2680 fps | 95.4% |
| Winchester StaBALL HD | <<locked>> | 84% | 26,252 psi | 41% | 2467 fps | 95.6% |
| Winchester StaBALL Match | <<locked>> | 80% | 51,735 psi | 81% | 2874 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 94% | 44,744 psi | 70% | 2779 fps | 95.5% |
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 100 powders for .255 GS loaded with the .257 | 117gr | Hornady InterLock RN. Alliant Reloder-26 delivers the highest muzzle velocity at 3,143 fps; across all powders the maximum-charge window runs from 1,834 fps to 3,143 fps. Accurate 3100 gives the best case fill at 100 %, and 100 of the 100 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 117.0 gr projectile in 0.257" calls for a 1:11.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2213, Alliant Reloder-22 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, Alliant Reloder-16, Alliant Reloder-26 rank at the top here: for .255 GS with the .257 | 117gr | Hornady InterLock RN 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.