Load Specifications
Load data in caliber .255 GS with .257 | 120gr | Speer Grand Slam bullet and 95 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-26 and Hodgdon Superformance.
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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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>> | 82% | 55,216 psi | 87% | 2802 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 56,188 psi | 88% | 2867 fps | 98.8% |
| Accurate 3100ᴾ | <<locked>> | 100% | 53,954 psi | 85% | 2910 fps | 99.6% |
| Accurate 4064 | <<locked>> | 84% | 55,521 psi | 87% | 2858 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 56,376 psi | 88% | 2966 fps | 100% |
| Accurate MAGPROᴾ | <<locked>> | 100% | 56,260 psi | 88% | 3054 fps | 96.2% |
| ADI AR 2208 | <<locked>> | 86% | 55,288 psi | 87% | 2884 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 57,159 psi | 90% | 3005 fps | 98.4% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 54,897 psi | 86% | 2999 fps | 96.8% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 54,505 psi | 85% | 3005 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 56,188 psi | 88% | 2910 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 56,463 psi | 88% | 2933 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 56,739 psi | 89% | 3018 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 54,418 psi | 85% | 2989 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 56,507 psi | 89% | 2995 fps | 98.4% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 53,780 psi | 84% | 2995 fps | 98.1% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 50,749 psi | 80% | 2930 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 44,034 psi | 69% | 2848 fps | 99% |
| Alliant Reloder-26 | <<locked>> | 98% | 54,418 psi | 85% | 3071 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 49,052 psi | 77% | 2913 fps | 97% |
| Bofors RP3 | <<locked>> | 86% | 57,087 psi | 89% | 2927 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 53,780 psi | 84% | 2995 fps | 98.1% |
| Bofors RP7 | <<locked>> | 90% | 56,608 psi | 89% | 2913 fps | 99% |
| Hodgdon H380 | <<locked>> | 86% | 57,493 psi | 90% | 2943 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 54,549 psi | 85% | 2959 fps | 99.2% |
| Hodgdon H4350 | <<locked>> | 88% | 54,563 psi | 86% | 2920 fps | 98.2% |
| Hodgdon H4831 | <<locked>> | 98% | 54,766 psi | 86% | 2940 fps | 96.1% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 57,638 psi | 90% | 2986 fps | 96.7% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 57,159 psi | 90% | 2940 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 55,274 psi | 87% | 2930 fps | 100% |
| Hodgdon Superformance | <<locked>> | 90% | 54,853 psi | 86% | 2995 fps | 99.1% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,535 psi | 57% | 1814 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 55,709 psi | 87% | 2887 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 54,795 psi | 86% | 2867 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 57,406 psi | 90% | 2904 fps | 99.4% |
| IMR 4350 | <<locked>> | 94% | 57,363 psi | 90% | 2943 fps | 99.1% |
| IMR 4451 Enduron | <<locked>> | 88% | 54,563 psi | 86% | 2884 fps | 99% |
| IMR 4831 | <<locked>> | 94% | 56,652 psi | 89% | 2953 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 54,476 psi | 85% | 2907 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 56,550 psi | 89% | 2933 fps | 96.7% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 52,083 psi | 82% | 2966 fps | 96.3% |
| Lovex S060 | <<locked>> | 82% | 56,347 psi | 88% | 2854 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 55,056 psi | 86% | 2861 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 54,752 psi | 86% | 2884 fps | 99.7% |
| Lovex S070 | <<locked>> | 92% | 55,941 psi | 88% | 2923 fps | 99.4% |
| Lovex S071ᴾ | <<locked>> | 100% | 44,904 psi | 70% | 2759 fps | 98.4% |
| Norma 201 | <<locked>> | 82% | 56,579 psi | 89% | 2874 fps | 100% |
| Norma 202 | <<locked>> | 82% | 57,188 psi | 90% | 2871 fps | 100% |
| Norma 203B | <<locked>> | 84% | 55,753 psi | 87% | 2917 fps | 100% |
| Norma 204 | <<locked>> | 92% | 54,607 psi | 86% | 2940 fps | 97.8% |
| Norma MRPᴾ | <<locked>> | 100% | 57,290 psi | 90% | 3087 fps | 99.5% |
| Norma URP | <<locked>> | 92% | 54,665 psi | 86% | 2946 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 56,434 psi | 88% | 2943 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 52,475 psi | 82% | 2982 fps | 96.8% |
| Ramshot Hunter | <<locked>> | 94% | 57,348 psi | 90% | 3005 fps | 99.8% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 46,920 psi | 74% | 2854 fps | 97.3% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,101 psi | 58% | 1854 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 57,348 psi | 90% | 2930 fps | 99.6% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 53,838 psi | 84% | 2982 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 55,927 psi | 88% | 2986 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 54,607 psi | 86% | 3015 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 42,946 psi | 67% | 2864 fps | 97.2% |
| Rottweil R 902 | <<locked>> | 84% | 57,290 psi | 90% | 2877 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 57,290 psi | 90% | 2923 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 55,143 psi | 86% | 2920 fps | 97% |
| Rottweil R 905 | <<locked>> | 98% | 55,709 psi | 87% | 2982 fps | 98.4% |
| Rottweil R 907 | <<locked>> | 90% | 56,608 psi | 89% | 2913 fps | 99% |
| Shooters World Long Rifle | <<locked>> | 90% | 54,752 psi | 86% | 2884 fps | 99.7% |
| Shooters World Precision | <<locked>> | 84% | 55,056 psi | 86% | 2861 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 55,941 psi | 88% | 2923 fps | 99.4% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 55,187 psi | 86% | 2930 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 56,304 psi | 88% | 2907 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 57,305 psi | 90% | 2802 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 54,607 psi | 86% | 2756 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 54,331 psi | 85% | 2835 fps | 99.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 55,259 psi | 87% | 2976 fps | 98.3% |
| Somchem S335 | <<locked>> | 82% | 57,029 psi | 89% | 2799 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 57,145 psi | 90% | 2917 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 57,203 psi | 90% | 2917 fps | 96.6% |
| Somchem S365 | <<locked>> | 94% | 53,969 psi | 85% | 2949 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 56,231 psi | 88% | 2953 fps | 99% |
| Vihtavuori N135 | <<locked>> | 84% | 57,348 psi | 90% | 2828 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 57,624 psi | 90% | 2844 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 54,955 psi | 86% | 2841 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 57,145 psi | 90% | 2943 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 52,011 psi | 82% | 2874 fps | 98.1% |
| Vihtavuori N540 | <<locked>> | 84% | 56,043 psi | 88% | 2848 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 56,101 psi | 88% | 2946 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 56,753 psi | 89% | 3009 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 57,537 psi | 90% | 3074 fps | 97.1% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 56,710 psi | 89% | 2910 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 54,911 psi | 86% | 2963 fps | 99.2% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 45,832 psi | 72% | 2989 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 56,463 psi | 88% | 2913 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 56,666 psi | 89% | 2949 fps | 98.3% |
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% | 51,459 psi | 81% | 2749 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 49,182 psi | 77% | 2753 fps | 97.7% |
| Accurate 3100 | <<locked>> | 86% | 33,417 psi | 52% | 2513 fps | 95% |
| Accurate 4064 | <<locked>> | 80% | 48,776 psi | 76% | 2756 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 37,115 psi | 58% | 2618 fps | 98% |
| Accurate MAGPRO | <<locked>> | 98% | 52,388 psi | 82% | 2992 fps | 95.3% |
| ADI AR 2208 | <<locked>> | 80% | 46,021 psi | 72% | 2730 fps | 99.7% |
| ADI AR 2209 | <<locked>> | 90% | 44,092 psi | 69% | 2772 fps | 95.5% |
| ADI AR 2213 | <<locked>> | 96% | 48,008 psi | 75% | 2874 fps | 95.1% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 50,792 psi | 80% | 2946 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 46,702 psi | 73% | 2759 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 49,632 psi | 78% | 2822 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 36,405 psi | 57% | 2631 fps | 98.2% |
| Alliant Reloder-17 | <<locked>> | 80% | 41,205 psi | 65% | 2759 fps | 99.9% |
| Alliant Reloder-19 | <<locked>> | 90% | 43,555 psi | 68% | 2762 fps | 95.5% |
| Alliant Reloder-22 | <<locked>> | 94% | 43,816 psi | 69% | 2812 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 26,556 psi | 42% | 2375 fps | 95.6% |
| Alliant Reloder-25 | <<locked>> | 92% | 34,229 psi | 54% | 2612 fps | 95.9% |
| Alliant Reloder-26 | 45.7 gr | 82% | 30,472 psi | 48% | 2549 fps | 95% |
| Bofors RP15 | <<locked>> | 96% | 43,207 psi | 68% | 2799 fps | 95.4% |
| Bofors RP3 | <<locked>> | 80% | 46,963 psi | 74% | 2769 fps | 100% |
| Bofors RP5 | <<locked>> | 94% | 43,816 psi | 69% | 2812 fps | 95.8% |
| Bofors RP7 | <<locked>> | 80% | 41,379 psi | 65% | 2638 fps | 96% |
| Hodgdon H380 | <<locked>> | 80% | 47,152 psi | 74% | 2776 fps | 99.4% |
| Hodgdon H414 | <<locked>> | 80% | 39,131 psi | 61% | 2664 fps | 96% |
| Hodgdon H4350 | <<locked>> | 80% | 42,163 psi | 66% | 2687 fps | 95.4% |
| Hodgdon H4831 | <<locked>> | 96% | 51,343 psi | 80% | 2881 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 96% | 50,372 psi | 79% | 2867 fps | 95.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 33,852 psi | 53% | 2523 fps | 98.7% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 51,619 psi | 81% | 2874 fps | 100% |
| Hodgdon Superformance | 45.9 gr | 80% | 38,029 psi | 60% | 2671 fps | 95.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,296 psi | 43% | 1621 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 52,402 psi | 82% | 2838 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 48,385 psi | 76% | 2762 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 80% | 50,604 psi | 79% | 2792 fps | 98.5% |
| IMR 4350 | <<locked>> | 82% | 39,291 psi | 62% | 2615 fps | 95.3% |
| IMR 4451 Enduron | <<locked>> | 80% | 42,569 psi | 67% | 2664 fps | 96.8% |
| IMR 4831 | <<locked>> | 80% | 35,897 psi | 56% | 2572 fps | 97.7% |
| IMR 4895 | <<locked>> | 80% | 50,894 psi | 80% | 2851 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 49,821 psi | 78% | 2818 fps | 95.2% |
| IMR 7828 SSC | <<locked>> | 98% | 48,863 psi | 77% | 2907 fps | 95.5% |
| Lovex S060 | <<locked>> | 80% | 53,040 psi | 83% | 2805 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 48,675 psi | 76% | 2762 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 40,132 psi | 63% | 2615 fps | 97.6% |
| Lovex S070 | <<locked>> | 80% | 38,522 psi | 60% | 2595 fps | 96% |
| Lovex S071 | <<locked>> | 92% | 34,751 psi | 54% | 2546 fps | 95.6% |
| Norma 201 | <<locked>> | 80% | 52,910 psi | 83% | 2822 fps | 100% |
| Norma 202 | <<locked>> | 80% | 53,809 psi | 84% | 2822 fps | 100% |
| Norma 203B | <<locked>> | 80% | 48,994 psi | 77% | 2808 fps | 100% |
| Norma 204 | <<locked>> | 86% | 44,599 psi | 70% | 2762 fps | 95.6% |
| Norma MRP | <<locked>> | 88% | 37,710 psi | 59% | 2707 fps | 95.2% |
| Norma URP | <<locked>> | 80% | 37,086 psi | 58% | 2615 fps | 97.9% |
| Ramshot Big Game | <<locked>> | 80% | 49,313 psi | 77% | 2831 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 48,762 psi | 76% | 2913 fps | 95.8% |
| Ramshot Hunter | <<locked>> | 80% | 35,926 psi | 56% | 2598 fps | 95.8% |
| Ramshot Magnum | <<locked>> | 96% | 40,553 psi | 64% | 2726 fps | 95.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,615 psi | 43% | 1657 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 47,268 psi | 74% | 2759 fps | 98.5% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 43,787 psi | 69% | 2815 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 36,912 psi | 58% | 2635 fps | 97.7% |
| ReloadSwiss RS 70 | 44.1 gr | 80% | 35,853 psi | 56% | 2638 fps | 96.9% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 40,118 psi | 63% | 2795 fps | 96.1% |
| Rottweil R 902 | <<locked>> | 80% | 50,662 psi | 79% | 2776 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 44,208 psi | 69% | 2713 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 48,660 psi | 76% | 2808 fps | 95.6% |
| Rottweil R 905 | <<locked>> | 90% | 42,743 psi | 67% | 2746 fps | 95.5% |
| Rottweil R 907 | <<locked>> | 80% | 41,379 psi | 65% | 2638 fps | 96% |
| Shooters World Long Rifle | <<locked>> | 80% | 40,132 psi | 63% | 2615 fps | 97.6% |
| Shooters World Precision | <<locked>> | 80% | 48,675 psi | 76% | 2762 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 38,522 psi | 60% | 2595 fps | 96% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 45,310 psi | 71% | 2766 fps | 99.9% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 52,707 psi | 83% | 2851 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 53,838 psi | 84% | 2756 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 45,513 psi | 71% | 2621 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 39,320 psi | 62% | 2559 fps | 96.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 42,337 psi | 66% | 2743 fps | 95.3% |
| Somchem S335 | <<locked>> | 80% | 53,403 psi | 84% | 2749 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 44,396 psi | 70% | 2710 fps | 99.9% |
| Somchem S361 | <<locked>> | 92% | 50,111 psi | 79% | 2799 fps | 95% |
| Somchem S365 | <<locked>> | 80% | 33,460 psi | 52% | 2569 fps | 99.5% |
| Somchem S385 | <<locked>> | 88% | 40,640 psi | 64% | 2674 fps | 95.8% |
| Vihtavuori N135 | <<locked>> | 80% | 50,821 psi | 80% | 2740 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 50,981 psi | 80% | 2753 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 42,496 psi | 67% | 2641 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 38,334 psi | 60% | 2612 fps | 98.2% |
| Vihtavuori N165 | <<locked>> | 92% | 40,045 psi | 63% | 2651 fps | 95.1% |
| Vihtavuori N540 | <<locked>> | 80% | 49,095 psi | 77% | 2746 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 37,826 psi | 59% | 2612 fps | 97.9% |
| Vihtavuori N555 | <<locked>> | 80% | 29,196 psi | 46% | 2454 fps | 95.8% |
| Vihtavuori N560 | <<locked>> | 96% | 50,067 psi | 78% | 2946 fps | 95.4% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 37,608 psi | 59% | 2582 fps | 99.6% |
| Winchester 760 | <<locked>> | 80% | 39,378 psi | 62% | 2671 fps | 96% |
| Winchester StaBALL HD | <<locked>> | 82% | 25,150 psi | 39% | 2402 fps | 95.2% |
| Winchester StaBALL Match | <<locked>> | 80% | 52,779 psi | 83% | 2858 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 42,670 psi | 67% | 2710 fps | 95.2% |
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 95 powders for .255 GS loaded with the .257 | 120gr | Speer Grand Slam. Norma MRP delivers the highest muzzle velocity at 3,087 fps; across all powders the maximum-charge window runs from 1,814 fps to 3,087 fps. Accurate 3100 gives the best case fill at 100 %, and 95 of the 95 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 120.0 gr projectile in 0.257" calls for a 1:11.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate MAGPRO, ADI AR 2213 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-26, Hodgdon Superformance rank at the top here: for .255 GS with the .257 | 120gr | Speer Grand Slam 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.