Load Specifications
Load data in caliber 8 x 57 PCC with .321 | 170gr | Remington SP Core-Lokt bullet and 98 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.
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You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 23.62"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 82% | 55,332 psi | 87% | 2877 fps | 100% |
| Accurate 2495 | <<locked>> | 86% | 54,708 psi | 86% | 2907 fps | 100% |
| Accurate 2520 | <<locked>> | 82% | 56,115 psi | 88% | 2972 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 56,826 psi | 89% | 2959 fps | 97.4% |
| Accurate 3100ᴾ | <<locked>> | 100% | 45,484 psi | 71% | 2854 fps | 96.9% |
| Accurate 4064 | <<locked>> | 88% | 54,824 psi | 86% | 2956 fps | 100% |
| Accurate 4350 | <<locked>> | 96% | 54,940 psi | 86% | 3041 fps | 99.6% |
| ADI AR 2206H | <<locked>> | 84% | 54,621 psi | 86% | 2982 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 90% | 55,709 psi | 87% | 2986 fps | 99.8% |
| ADI Benchmark 8208 | <<locked>> | 84% | 56,913 psi | 89% | 2986 fps | 100% |
| Alliant AR-Comp | <<locked>> | 82% | 54,650 psi | 86% | 2907 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 86% | 54,607 psi | 86% | 3110 fps | 99.9% |
| Alliant Power Pro Varmintᴾ | <<locked>> | 100% | 52,721 psi | 83% | 3012 fps | 95.8% |
| Alliant Power Pro Varmintᴾ | <<locked>> | 100% | 52,721 psi | 83% | 3012 fps | 95.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 90% | 56,057 psi | 88% | 3009 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 88% | 56,550 psi | 89% | 3035 fps | 99.9% |
| Alliant Reloder-16 | <<locked>> | 98% | 55,869 psi | 88% | 3104 fps | 99.9% |
| Alliant Reloder-17 | <<locked>> | 94% | 57,290 psi | 90% | 3140 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 43,120 psi | 68% | 2884 fps | 99.4% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 48,689 psi | 76% | 3064 fps | 99% |
| Baschieri & Pellagri 107 | <<locked>> | 84% | 54,462 psi | 85% | 2995 fps | 99.6% |
| Bofors RP3 | <<locked>> | 90% | 56,942 psi | 89% | 3028 fps | 100% |
| Bofors RP7 | <<locked>> | 94% | 56,681 psi | 89% | 2999 fps | 97.6% |
| Hodgdon Benchmark | <<locked>> | 82% | 54,940 psi | 86% | 2913 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 84% | 56,739 psi | 89% | 3018 fps | 100% |
| Hodgdon H380 | <<locked>> | 90% | 57,624 psi | 90% | 3041 fps | 99.6% |
| Hodgdon H414 | <<locked>> | 94% | 54,012 psi | 85% | 3038 fps | 97.8% |
| Hodgdon H4350 | <<locked>> | 92% | 54,244 psi | 85% | 2999 fps | 96.5% |
| Hodgdon H4895 | <<locked>> | 84% | 55,172 psi | 86% | 2995 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 55,912 psi | 88% | 3025 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 86% | 55,013 psi | 86% | 3031 fps | 100% |
| Hodgdon Superformance | <<locked>> | 94% | 54,447 psi | 85% | 3074 fps | 97.6% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,766 psi | 56% | 1857 fps | 100% |
| Hodgdon VARGET | <<locked>> | 86% | 56,304 psi | 88% | 2999 fps | 100% |
| IMR 3031 | <<locked>> | 84% | 55,390 psi | 87% | 2976 fps | 100% |
| IMR 4064 | <<locked>> | 88% | 55,201 psi | 87% | 2969 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 86% | 54,911 psi | 86% | 2946 fps | 97.8% |
| IMR 4350 | <<locked>> | 98% | 57,188 psi | 90% | 3025 fps | 97.8% |
| IMR 4451 Enduron | <<locked>> | 92% | 54,911 psi | 86% | 2972 fps | 97.8% |
| IMR 4831 | <<locked>> | 98% | 55,521 psi | 87% | 3035 fps | 99.7% |
| IMR 4895 | <<locked>> | 86% | 54,520 psi | 85% | 3009 fps | 100% |
| IMR 8208 XBR | <<locked>> | 84% | 56,913 psi | 89% | 2986 fps | 100% |
| Lovex D073.6 | <<locked>> | 84% | 54,694 psi | 86% | 2959 fps | 100% |
| Lovex S060 | <<locked>> | 86% | 57,392 psi | 90% | 2963 fps | 100% |
| Lovex S062 | <<locked>> | 88% | 55,347 psi | 87% | 2969 fps | 100% |
| Lovex S065 | <<locked>> | 94% | 54,520 psi | 85% | 2966 fps | 98.8% |
| Lovex S070 | <<locked>> | 96% | 55,579 psi | 87% | 3005 fps | 98.2% |
| Norma 201 | <<locked>> | 86% | 56,826 psi | 89% | 2982 fps | 100% |
| Norma 202 | <<locked>> | 86% | 57,566 psi | 90% | 2982 fps | 100% |
| Norma 203B | <<locked>> | 88% | 55,796 psi | 87% | 3018 fps | 100% |
| Norma 204 | <<locked>> | 96% | 54,404 psi | 85% | 3022 fps | 96% |
| Norma MRPᴾ | <<locked>> | 100% | 48,341 psi | 76% | 3018 fps | 96.5% |
| Norma URP | <<locked>> | 98% | 57,595 psi | 90% | 3087 fps | 99.8% |
| Ramshot Big Game | <<locked>> | 88% | 56,536 psi | 89% | 3045 fps | 100% |
| Ramshot Hunter | <<locked>> | 98% | 56,260 psi | 88% | 3081 fps | 98.8% |
| Ramshot TAC | <<locked>> | 84% | 57,363 psi | 90% | 3009 fps | 99.3% |
| Ramshot Wild Boar | <<locked>> | 84% | 57,058 psi | 89% | 3022 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 82% | 57,696 psi | 90% | 2986 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,303 psi | 57% | 1900 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 54,143 psi | 85% | 2963 fps | 98.2% |
| ReloadSwiss RS 52 | <<locked>> | 86% | 57,290 psi | 90% | 3104 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 92% | 57,000 psi | 89% | 3136 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 96% | 54,839 psi | 86% | 3068 fps | 99.5% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 53,983 psi | 85% | 3094 fps | 99.3% |
| Rottweil R 901 | <<locked>> | 82% | 54,317 psi | 85% | 2910 fps | 100% |
| Rottweil R 902 | <<locked>> | 88% | 57,479 psi | 90% | 2979 fps | 100% |
| Rottweil R 903 | <<locked>> | 92% | 56,811 psi | 89% | 3022 fps | 100% |
| Rottweil R 907 | <<locked>> | 94% | 56,681 psi | 89% | 2999 fps | 97.6% |
| Shooters World Long Rifle | <<locked>> | 94% | 54,520 psi | 85% | 2966 fps | 98.8% |
| Shooters World Match Rifle | <<locked>> | 84% | 54,694 psi | 86% | 2959 fps | 100% |
| Shooters World Precision | <<locked>> | 88% | 55,347 psi | 87% | 2969 fps | 100% |
| Shooters World SW4350 | <<locked>> | 96% | 55,579 psi | 87% | 3005 fps | 98.2% |
| SNPE Vectan SP 11 | <<locked>> | 90% | 54,911 psi | 86% | 3028 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 84% | 55,898 psi | 88% | 2986 fps | 99.4% |
| SNPE Vectan SP 9 | <<locked>> | 86% | 56,594 psi | 89% | 3009 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 84% | 54,636 psi | 86% | 2867 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 90% | 55,245 psi | 87% | 2867 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 94% | 54,824 psi | 86% | 2920 fps | 97.8% |
| Somchem S335 | <<locked>> | 86% | 57,479 psi | 90% | 2910 fps | 100% |
| Somchem S341 | <<locked>> | 84% | 55,448 psi | 87% | 2972 fps | 100% |
| Somchem S355 | <<locked>> | 92% | 56,840 psi | 89% | 3015 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 55,927 psi | 88% | 3087 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 51,779 psi | 81% | 2966 fps | 96.7% |
| Vihtavuori N130 | <<locked>> | 82% | 57,740 psi | 90% | 2874 fps | 100% |
| Vihtavuori N133 | <<locked>> | 84% | 54,955 psi | 86% | 2851 fps | 100% |
| Vihtavuori N135 | <<locked>> | 88% | 57,348 psi | 90% | 2940 fps | 100% |
| Vihtavuori N140 | <<locked>> | 86% | 54,476 psi | 85% | 2907 fps | 100% |
| Vihtavuori N150 | <<locked>> | 92% | 54,839 psi | 86% | 2940 fps | 100% |
| Vihtavuori N160 | <<locked>> | 96% | 56,202 psi | 88% | 3025 fps | 99.6% |
| Vihtavuori N530 | <<locked>> | 84% | 57,508 psi | 90% | 2986 fps | 100% |
| Vihtavuori N540 | <<locked>> | 88% | 56,318 psi | 88% | 2953 fps | 100% |
| Vihtavuori N550 | <<locked>> | 96% | 55,506 psi | 87% | 3035 fps | 99.5% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 47,703 psi | 75% | 2966 fps | 99.3% |
| Winchester 6.5 StaBALL | <<locked>> | 96% | 56,536 psi | 89% | 3002 fps | 100% |
| Winchester 748 | <<locked>> | 82% | 54,099 psi | 85% | 2979 fps | 100% |
| Winchester 760 | <<locked>> | 94% | 54,244 psi | 85% | 3041 fps | 97.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 38,609 psi | 61% | 2897 fps | 99.5% |
| Winchester StaBALL Match | <<locked>> | 86% | 56,826 psi | 89% | 3018 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 23.62"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 80% | 52,185 psi | 82% | 2835 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 45,005 psi | 71% | 2756 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 52,460 psi | 82% | 2917 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 46,673 psi | 73% | 2782 fps | 95.2% |
| Accurate 3100 | <<locked>> | 96% | 39,552 psi | 62% | 2736 fps | 95.2% |
| Accurate 4064 | <<locked>> | 80% | 42,583 psi | 67% | 2753 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 33,866 psi | 53% | 2625 fps | 95.1% |
| ADI AR 2206H | <<locked>> | 80% | 48,066 psi | 75% | 2871 fps | 99.5% |
| ADI AR 2208 | <<locked>> | 80% | 40,872 psi | 64% | 2713 fps | 97.9% |
| ADI Benchmark 8208 | <<locked>> | 80% | 50,169 psi | 79% | 2877 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 51,140 psi | 80% | 2861 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 44,309 psi | 69% | 2917 fps | 98.6% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 49,545 psi | 78% | 2956 fps | 95% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 49,545 psi | 78% | 2956 fps | 95% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 40,799 psi | 64% | 2740 fps | 99.1% |
| Alliant Reloder-15 | <<locked>> | 80% | 43,714 psi | 69% | 2805 fps | 98.6% |
| Alliant Reloder-16 | <<locked>> | 82% | 33,736 psi | 53% | 2635 fps | 95.1% |
| Alliant Reloder-17 | 64.5 gr | 80% | 35,375 psi | 55% | 2707 fps | 97.6% |
| Alliant Reloder-23 | <<locked>> | 90% | 31,357 psi | 49% | 2595 fps | 95.9% |
| Alliant Reloder-26 | <<locked>> | 92% | 36,564 psi | 57% | 2789 fps | 95.5% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 47,601 psi | 75% | 2877 fps | 98.9% |
| Bofors RP3 | <<locked>> | 80% | 40,741 psi | 64% | 2743 fps | 99.2% |
| Bofors RP7 | <<locked>> | 88% | 46,862 psi | 73% | 2828 fps | 95.5% |
| Hodgdon Benchmark | <<locked>> | 80% | 51,750 psi | 81% | 2864 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 49,690 psi | 78% | 2907 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 41,466 psi | 65% | 2749 fps | 97% |
| Hodgdon H414 | <<locked>> | 88% | 44,295 psi | 69% | 2858 fps | 95.6% |
| Hodgdon H4350 | <<locked>> | 88% | 47,790 psi | 75% | 2881 fps | 95% |
| Hodgdon H4895 | <<locked>> | 80% | 48,588 psi | 76% | 2884 fps | 99.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 29,124 psi | 46% | 2474 fps | 95% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 44,933 psi | 70% | 2858 fps | 99.7% |
| Hodgdon Superformance | 76.8 gr | 90% | 47,166 psi | 74% | 2940 fps | 95.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,614 psi | 42% | 1660 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 46,514 psi | 73% | 2831 fps | 99.6% |
| IMR 3031 | <<locked>> | 80% | 48,791 psi | 76% | 2877 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 42,931 psi | 67% | 2749 fps | 98.6% |
| IMR 4166 Enduron | <<locked>> | 80% | 45,324 psi | 71% | 2772 fps | 95.8% |
| IMR 4350 | <<locked>> | 92% | 47,384 psi | 74% | 2858 fps | 95.7% |
| IMR 4451 Enduron | <<locked>> | 86% | 45,788 psi | 72% | 2805 fps | 95.8% |
| IMR 4831 | <<locked>> | 84% | 35,070 psi | 55% | 2638 fps | 95.7% |
| IMR 4895 | <<locked>> | 80% | 44,817 psi | 70% | 2838 fps | 99.2% |
| IMR 8208 XBR | <<locked>> | 80% | 50,169 psi | 79% | 2877 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 47,790 psi | 75% | 2851 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 47,834 psi | 75% | 2805 fps | 99.5% |
| Lovex S062 | <<locked>> | 80% | 43,120 psi | 68% | 2756 fps | 99.6% |
| Lovex S065 | <<locked>> | 84% | 40,147 psi | 63% | 2694 fps | 95.8% |
| Lovex S070 | <<locked>> | 88% | 43,410 psi | 68% | 2782 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 47,137 psi | 74% | 2822 fps | 99.9% |
| Norma 202 | <<locked>> | 80% | 47,529 psi | 74% | 2828 fps | 100% |
| Norma 203B | <<locked>> | 80% | 43,091 psi | 68% | 2792 fps | 98.9% |
| Norma 204 | <<locked>> | 94% | 50,778 psi | 80% | 2956 fps | 95.1% |
| Norma MRP | <<locked>> | 98% | 45,150 psi | 71% | 2949 fps | 95.5% |
| Norma URP | <<locked>> | 82% | 34,026 psi | 53% | 2625 fps | 95% |
| Ramshot Big Game | <<locked>> | 80% | 43,047 psi | 67% | 2812 fps | 98.8% |
| Ramshot Hunter | <<locked>> | 88% | 40,408 psi | 63% | 2782 fps | 95.3% |
| Ramshot TAC | <<locked>> | 80% | 50,314 psi | 79% | 2890 fps | 98.3% |
| Ramshot Wild Boar | <<locked>> | 80% | 50,096 psi | 79% | 2910 fps | 99.7% |
| Ramshot X-Terminator | <<locked>> | 80% | 54,157 psi | 85% | 2930 fps | 99.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,006 psi | 42% | 1699 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 41,684 psi | 65% | 2730 fps | 95.4% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 46,499 psi | 73% | 2920 fps | 99% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 37,637 psi | 59% | 2776 fps | 99.8% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 35,969 psi | 56% | 2697 fps | 95.5% |
| ReloadSwiss RS 70 | 70.5 gr | 86% | 38,276 psi | 60% | 2769 fps | 95.6% |
| Rottweil R 901 | <<locked>> | 80% | 51,271 psi | 80% | 2864 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 44,817 psi | 70% | 2772 fps | 99.7% |
| Rottweil R 903 | <<locked>> | 80% | 38,421 psi | 60% | 2687 fps | 98.5% |
| Rottweil R 907 | <<locked>> | 88% | 46,862 psi | 73% | 2828 fps | 95.5% |
| Shooters World Long Rifle | <<locked>> | 84% | 40,147 psi | 63% | 2694 fps | 95.8% |
| Shooters World Match Rifle | <<locked>> | 80% | 47,790 psi | 75% | 2851 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 43,120 psi | 68% | 2756 fps | 99.6% |
| Shooters World SW4350 | <<locked>> | 88% | 43,410 psi | 68% | 2782 fps | 95.5% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 39,262 psi | 62% | 2736 fps | 98.1% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 48,704 psi | 76% | 2864 fps | 98.5% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 46,572 psi | 73% | 2838 fps | 99.4% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 48,283 psi | 76% | 2769 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 40,422 psi | 63% | 2628 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 44,918 psi | 70% | 2749 fps | 95.7% |
| Somchem S335 | <<locked>> | 80% | 47,979 psi | 75% | 2769 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 48,428 psi | 76% | 2858 fps | 99.5% |
| Somchem S355 | <<locked>> | 80% | 39,001 psi | 61% | 2690 fps | 98.5% |
| Somchem S365 | <<locked>> | 80% | 28,558 psi | 45% | 2513 fps | 96.3% |
| Somchem S385 | <<locked>> | 96% | 45,368 psi | 71% | 2848 fps | 95.1% |
| Vihtavuori N130 | <<locked>> | 80% | 54,259 psi | 85% | 2828 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 48,689 psi | 76% | 2759 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 44,643 psi | 70% | 2749 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 45,150 psi | 71% | 2759 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 37,217 psi | 58% | 2625 fps | 99.1% |
| Vihtavuori N160 | <<locked>> | 82% | 35,534 psi | 56% | 2631 fps | 95.5% |
| Vihtavuori N530 | <<locked>> | 80% | 50,459 psi | 79% | 2874 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 43,540 psi | 68% | 2749 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 34,925 psi | 55% | 2625 fps | 95% |
| Vihtavuori N555 | <<locked>> | 88% | 32,068 psi | 50% | 2618 fps | 95.1% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 32,822 psi | 51% | 2543 fps | 96.9% |
| Winchester 748 | <<locked>> | 80% | 50,575 psi | 79% | 2927 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 44,295 psi | 69% | 2858 fps | 95.6% |
| Winchester StaBALL HD | <<locked>> | 92% | 29,718 psi | 47% | 2618 fps | 95.5% |
| Winchester StaBALL Match | <<locked>> | 80% | 46,383 psi | 73% | 2848 fps | 99.6% |
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 98 powders for 8 x 57 PCC loaded with the .321 | 170gr | Remington SP Core-Lokt. Alliant Reloder-17 delivers the highest muzzle velocity at 3,140 fps; across all powders the maximum-charge window runs from 1,857 fps to 3,140 fps. Accurate 3100 gives the best case fill at 100 %, and 98 of the 98 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 56–90 %, leaving at least 10 % headroom. The 170.0 gr projectile in 0.321" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, Alliant Power Pro Varmint, Alliant Power Pro Varmint 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 8 x 57 PCC with the .321 | 170gr | Remington SP Core-Lokt 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.