Load Specifications
Bullet:.257 | 100gr | Swift A-Frame
Bullet Manufacturer:Swift
Bullet Weight:100 gr
Bullet Diameter:0.257"
Bullet Length:<<locked>>
Caliber:.25 WSSM load data
Case Length (l3):1.67"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:54.3 Grains of Water
Primer Size:Large Rifle (LR)
Barrel Length:24"
Max. allowed Pressure:63,817 psi
Recommended Twist Rate:1:11.5
Load data in caliber .25 WSSM with .257 | 100gr | Swift A-Frame bullet and 101 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Power Pro 2000-MR, ReloadSwiss RS 60 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: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 86% | 55,666 psi | 87% | 2995 fps | 100% |
| Accurate 2460 | <<locked>> | 82% | 54,244 psi | 85% | 3022 fps | 100% |
| Accurate 2495 | <<locked>> | 92% | 57,479 psi | 90% | 3061 fps | 100% |
| Accurate 2520 | <<locked>> | 86% | 54,128 psi | 85% | 3064 fps | 100% |
| Accurate 4064 | <<locked>> | 94% | 57,276 psi | 90% | 3107 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 53,447 psi | 84% | 3127 fps | 98.9% |
| ADI AR 2206H | <<locked>> | 88% | 54,650 psi | 86% | 3091 fps | 99.6% |
| ADI AR 2208 | <<locked>> | 94% | 55,767 psi | 87% | 3087 fps | 99.4% |
| ADI Benchmark 8208 | <<locked>> | 88% | 57,217 psi | 90% | 3094 fps | 100% |
| Alliant AR-Comp | <<locked>> | 86% | 54,157 psi | 85% | 3025 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 82% | 55,608 psi | 87% | 3159 fps | 99.9% |
| Alliant Power Pro 2000-MR | <<locked>> | 90% | 54,230 psi | 85% | 3205 fps | 99.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 94% | 55,666 psi | 87% | 3114 fps | 99.9% |
| Alliant Reloder-10x | <<locked>> | 82% | 55,317 psi | 87% | 3002 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 92% | 56,405 psi | 88% | 3136 fps | 99.5% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 51,576 psi | 81% | 3130 fps | 98.9% |
| Alliant Reloder-17 | <<locked>> | 98% | 56,492 psi | 89% | 3238 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 36,709 psi | 58% | 2828 fps | 96.7% |
| Baschieri & Pellagri 106 | <<locked>> | 82% | 57,130 psi | 90% | 2972 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 88% | 54,650 psi | 86% | 3104 fps | 99.1% |
| Bofors RP3 | <<locked>> | 94% | 56,057 psi | 88% | 3127 fps | 100% |
| Bofors RP7 | <<locked>> | 98% | 56,652 psi | 89% | 3091 fps | 96.4% |
| Hodgdon Benchmark | <<locked>> | 86% | 55,666 psi | 87% | 3028 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 88% | 56,565 psi | 89% | 3123 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 84% | 55,027 psi | 86% | 3176 fps | 99.4% |
| Hodgdon H322 | <<locked>> | 82% | 54,215 psi | 85% | 3038 fps | 100% |
| Hodgdon H335 | <<locked>> | 82% | 55,376 psi | 87% | 3064 fps | 100% |
| Hodgdon H380 | <<locked>> | 94% | 57,450 psi | 90% | 3140 fps | 98.9% |
| Hodgdon H414ᴾ | <<locked>> | 100% | 56,695 psi | 89% | 3182 fps | 97.2% |
| Hodgdon H4350 | <<locked>> | 98% | 57,595 psi | 90% | 3143 fps | 95.8% |
| Hodgdon H4895 | <<locked>> | 88% | 55,230 psi | 87% | 3104 fps | 99.8% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 47,688 psi | 75% | 2999 fps | 99.2% |
| Hodgdon LEVERevolution | <<locked>> | 90% | 54,578 psi | 86% | 3136 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 98% | 54,201 psi | 85% | 3159 fps | 96.1% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,128 psi | 55% | 1900 fps | 100% |
| Hodgdon VARGET | <<locked>> | 90% | 56,623 psi | 89% | 3107 fps | 99.9% |
| IMR 3031 | <<locked>> | 88% | 55,071 psi | 86% | 3094 fps | 100% |
| IMR 4064 | <<locked>> | 92% | 55,172 psi | 86% | 3071 fps | 99.5% |
| IMR 4166 Enduron | <<locked>> | 90% | 55,390 psi | 87% | 3045 fps | 96.7% |
| IMR 4198 | <<locked>> | 82% | 55,143 psi | 86% | 2959 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 96% | 55,216 psi | 87% | 3071 fps | 96.6% |
| IMR 4831ᴾ | <<locked>> | 100% | 50,589 psi | 79% | 3061 fps | 98.5% |
| IMR 4895 | <<locked>> | 90% | 53,983 psi | 85% | 3110 fps | 99.6% |
| IMR 8208 XBR | <<locked>> | 88% | 57,217 psi | 90% | 3094 fps | 100% |
| Lovex D073.5 | <<locked>> | 82% | 53,940 psi | 85% | 3025 fps | 100% |
| Lovex D073.6 | <<locked>> | 88% | 54,128 psi | 85% | 3064 fps | 100% |
| Lovex S060 | <<locked>> | 88% | 54,418 psi | 85% | 3015 fps | 99.6% |
| Lovex S062 | <<locked>> | 92% | 54,882 psi | 86% | 3068 fps | 100% |
| Lovex S065ᴾ | <<locked>> | 100% | 57,522 psi | 90% | 3110 fps | 98.3% |
| Lovex S070ᴾ | <<locked>> | 100% | 54,926 psi | 86% | 3091 fps | 96.9% |
| Norma 201 | <<locked>> | 90% | 56,753 psi | 89% | 3087 fps | 100% |
| Norma 202 | <<locked>> | 90% | 57,595 psi | 90% | 3094 fps | 100% |
| Norma 203B | <<locked>> | 92% | 55,564 psi | 87% | 3123 fps | 99.7% |
| Norma URPᴾ | <<locked>> | 100% | 52,591 psi | 82% | 3117 fps | 98.7% |
| Ramshot Big Game | <<locked>> | 92% | 56,086 psi | 88% | 3146 fps | 99.7% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 51,663 psi | 81% | 3104 fps | 97% |
| Ramshot TAC | <<locked>> | 86% | 54,288 psi | 85% | 3054 fps | 98% |
| Ramshot Wild Boar | <<locked>> | 88% | 57,479 psi | 90% | 3136 fps | 99.8% |
| Ramshot X-Terminator | <<locked>> | 84% | 54,955 psi | 86% | 3045 fps | 99.6% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,549 psi | 56% | 1946 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 84% | 56,695 psi | 89% | 3077 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 92% | 54,070 psi | 85% | 3058 fps | 97.1% |
| ReloadSwiss RS 52 | <<locked>> | 90% | 56,739 psi | 89% | 3205 fps | 99.6% |
| ReloadSwiss RS 60 | <<locked>> | 96% | 56,115 psi | 88% | 3241 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 53,142 psi | 83% | 3146 fps | 98.6% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 53,388 psi | 84% | 3176 fps | 98.3% |
| Rottweil R 901 | <<locked>> | 86% | 54,375 psi | 85% | 3022 fps | 100% |
| Rottweil R 902 | <<locked>> | 92% | 57,203 psi | 90% | 3084 fps | 100% |
| Rottweil R 903 | <<locked>> | 96% | 55,912 psi | 88% | 3117 fps | 99.9% |
| Rottweil R 907 | <<locked>> | 98% | 56,652 psi | 89% | 3091 fps | 96.4% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 57,522 psi | 90% | 3110 fps | 98.3% |
| Shooters World Match Rifle | <<locked>> | 88% | 54,128 psi | 85% | 3064 fps | 100% |
| Shooters World Precision | <<locked>> | 92% | 54,882 psi | 86% | 3068 fps | 100% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 54,926 psi | 86% | 3091 fps | 96.9% |
| Shooters World Tactical Rifle | <<locked>> | 82% | 56,492 psi | 89% | 3048 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 94% | 54,346 psi | 85% | 3127 fps | 99.6% |
| SNPE Vectan SP 3 | <<locked>> | 82% | 55,912 psi | 88% | 3022 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 88% | 56,405 psi | 88% | 3091 fps | 98.7% |
| SNPE Vectan SP 9 | <<locked>> | 90% | 56,826 psi | 89% | 3117 fps | 99.8% |
| SNPE Vectan Tubal 3000 | <<locked>> | 88% | 55,085 psi | 86% | 2976 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 94% | 55,114 psi | 86% | 2972 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 98% | 54,766 psi | 86% | 3009 fps | 96.6% |
| Somchem S321 | <<locked>> | 84% | 55,056 psi | 86% | 3077 fps | 100% |
| Somchem S335 | <<locked>> | 90% | 57,725 psi | 90% | 3022 fps | 100% |
| Somchem S341 | <<locked>> | 88% | 55,825 psi | 87% | 3081 fps | 99.7% |
| Somchem S355 | <<locked>> | 96% | 56,173 psi | 88% | 3114 fps | 99.9% |
| Somchem S365ᴾ | <<locked>> | 100% | 47,224 psi | 74% | 3064 fps | 99.9% |
| Vihtavuori N130 | <<locked>> | 84% | 54,911 psi | 86% | 2946 fps | 100% |
| Vihtavuori N133 | <<locked>> | 88% | 55,201 psi | 87% | 2963 fps | 100% |
| Vihtavuori N135 | <<locked>> | 92% | 57,014 psi | 89% | 3054 fps | 100% |
| Vihtavuori N140 | <<locked>> | 90% | 54,520 psi | 85% | 3018 fps | 100% |
| Vihtavuori N150 | <<locked>> | 96% | 54,404 psi | 85% | 3041 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 55,303 psi | 87% | 3114 fps | 98.9% |
| Vihtavuori N530 | <<locked>> | 86% | 54,201 psi | 85% | 3041 fps | 100% |
| Vihtavuori N540 | <<locked>> | 92% | 56,405 psi | 88% | 3068 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 54,346 psi | 85% | 3117 fps | 98.7% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 39,610 psi | 62% | 2913 fps | 96.7% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 56,304 psi | 88% | 3097 fps | 100% |
| Winchester 748 | <<locked>> | 86% | 53,882 psi | 84% | 3091 fps | 100% |
| Winchester 760ᴾ | <<locked>> | 100% | 57,072 psi | 89% | 3189 fps | 97.2% |
| Winchester StaBALL Match | <<locked>> | 90% | 56,782 psi | 89% | 3127 fps | 99.9% |
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 2015 | <<locked>> | 80% | 46,253 psi | 72% | 2848 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 50,531 psi | 79% | 2963 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 38,885 psi | 61% | 2756 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 44,266 psi | 69% | 2900 fps | 99.9% |
| Accurate 4064 | <<locked>> | 80% | 36,753 psi | 58% | 2743 fps | 99.6% |
| Accurate 4350 | <<locked>> | 90% | 37,521 psi | 59% | 2815 fps | 95.2% |
| ADI AR 2206H | <<locked>> | 80% | 42,583 psi | 67% | 2864 fps | 97.9% |
| ADI AR 2208 | <<locked>> | 80% | 36,187 psi | 57% | 2697 fps | 95.3% |
| ADI Benchmark 8208 | <<locked>> | 80% | 44,657 psi | 70% | 2877 fps | 99.2% |
| Alliant AR-Comp | <<locked>> | 80% | 44,469 psi | 70% | 2874 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 52,098 psi | 82% | 3100 fps | 99.7% |
| Alliant Power Pro 2000-MR | 39 gr | 80% | 38,609 psi | 61% | 2877 fps | 95.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 35,665 psi | 56% | 2720 fps | 97% |
| Alliant Reloder-10x | <<locked>> | 80% | 51,909 psi | 81% | 2953 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 38,377 psi | 60% | 2785 fps | 96.3% |
| Alliant Reloder-16 | <<locked>> | 90% | 37,956 psi | 59% | 2835 fps | 95.3% |
| Alliant Reloder-17 | 39.3 gr | 82% | 32,837 psi | 51% | 2726 fps | 95.1% |
| Alliant Reloder-23 | <<locked>> | 98% | 34,548 psi | 54% | 2772 fps | 95.8% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 53,505 psi | 84% | 2920 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 41,481 psi | 65% | 2854 fps | 96.6% |
| Bofors RP3 | <<locked>> | 80% | 35,172 psi | 55% | 2720 fps | 97% |
| Bofors RP7 | <<locked>> | 96% | 53,185 psi | 83% | 3031 fps | 95.7% |
| Hodgdon Benchmark | <<locked>> | 80% | 46,340 psi | 73% | 2867 fps | 99.7% |
| Hodgdon BL-C2 | <<locked>> | 80% | 43,337 psi | 68% | 2897 fps | 99.4% |
| Hodgdon CFE223 | <<locked>> | 80% | 47,659 psi | 75% | 3045 fps | 98.5% |
| Hodgdon H322 | <<locked>> | 80% | 50,836 psi | 80% | 2986 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 51,967 psi | 81% | 3012 fps | 100% |
| Hodgdon H380 | <<locked>> | 84% | 41,118 psi | 64% | 2838 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 96% | 49,472 psi | 78% | 3058 fps | 95.6% |
| Hodgdon H4350 | <<locked>> | 96% | 54,157 psi | 85% | 3087 fps | 95.1% |
| Hodgdon H4895 | <<locked>> | 80% | 42,975 psi | 67% | 2877 fps | 98.5% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 32,532 psi | 51% | 2661 fps | 95.2% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 38,769 psi | 61% | 2835 fps | 98% |
| Hodgdon Superformance | <<locked>> | 96% | 50,082 psi | 78% | 3081 fps | 95% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,063 psi | 41% | 1699 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 41,017 psi | 64% | 2818 fps | 98% |
| IMR 3031 | <<locked>> | 80% | 42,134 psi | 66% | 2877 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 37,913 psi | 59% | 2736 fps | 96.2% |
| IMR 4166 Enduron | <<locked>> | 86% | 48,965 psi | 77% | 2930 fps | 95.3% |
| IMR 4198 | <<locked>> | 80% | 52,069 psi | 82% | 2913 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 92% | 48,515 psi | 76% | 2949 fps | 95.1% |
| IMR 4831 | <<locked>> | 92% | 38,899 psi | 61% | 2828 fps | 95.8% |
| IMR 4895 | <<locked>> | 80% | 39,305 psi | 62% | 2822 fps | 97.2% |
| IMR 8208 XBR | <<locked>> | 80% | 44,657 psi | 70% | 2877 fps | 99.2% |
| Lovex D073.5 | <<locked>> | 80% | 50,285 psi | 79% | 2966 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 41,466 psi | 65% | 2844 fps | 99.7% |
| Lovex S060 | <<locked>> | 80% | 42,844 psi | 67% | 2802 fps | 98% |
| Lovex S062 | <<locked>> | 80% | 37,840 psi | 59% | 2743 fps | 98% |
| Lovex S065 | <<locked>> | 90% | 42,192 psi | 66% | 2831 fps | 95% |
| Lovex S070 | <<locked>> | 96% | 48,457 psi | 76% | 2976 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 41,742 psi | 65% | 2818 fps | 98.8% |
| Norma 202 | <<locked>> | 80% | 41,945 psi | 66% | 2831 fps | 99.9% |
| Norma 203B | <<locked>> | 80% | 37,768 psi | 59% | 2776 fps | 96.7% |
| Norma URP | <<locked>> | 90% | 37,985 psi | 60% | 2822 fps | 95.2% |
| Ramshot Big Game | <<locked>> | 80% | 37,275 psi | 58% | 2782 fps | 96.3% |
| Ramshot Hunter | <<locked>> | 96% | 45,266 psi | 71% | 2982 fps | 95.4% |
| Ramshot TAC | <<locked>> | 80% | 44,440 psi | 70% | 2871 fps | 95.9% |
| Ramshot Wild Boar | <<locked>> | 80% | 43,961 psi | 69% | 2897 fps | 98.2% |
| Ramshot X-Terminator | <<locked>> | 80% | 48,080 psi | 75% | 2923 fps | 98.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,527 psi | 42% | 1742 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 50,024 psi | 78% | 2969 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 47,456 psi | 74% | 2936 fps | 95.7% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 40,016 psi | 63% | 2894 fps | 96.7% |
| ReloadSwiss RS 60 | 38.4 gr | 80% | 32,808 psi | 51% | 2740 fps | 97.8% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 40,263 psi | 63% | 2900 fps | 95.7% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 43,540 psi | 68% | 2976 fps | 95.9% |
| Rottweil R 901 | <<locked>> | 80% | 45,426 psi | 71% | 2867 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 39,755 psi | 62% | 2766 fps | 98.4% |
| Rottweil R 903 | <<locked>> | 80% | 33,069 psi | 52% | 2661 fps | 95.9% |
| Rottweil R 907 | <<locked>> | 96% | 53,185 psi | 83% | 3031 fps | 95.7% |
| Shooters World Long Rifle | <<locked>> | 90% | 42,192 psi | 66% | 2831 fps | 95% |
| Shooters World Match Rifle | <<locked>> | 80% | 41,466 psi | 65% | 2844 fps | 99.7% |
| Shooters World Precision | <<locked>> | 80% | 37,840 psi | 59% | 2743 fps | 98% |
| Shooters World SW4350 | <<locked>> | 96% | 48,457 psi | 76% | 2976 fps | 95.5% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 53,026 psi | 83% | 2992 fps | 99.8% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 34,113 psi | 53% | 2710 fps | 95.2% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 52,750 psi | 83% | 2976 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 42,612 psi | 67% | 2841 fps | 96% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 41,147 psi | 64% | 2828 fps | 97.6% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 43,120 psi | 68% | 2776 fps | 99.9% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 35,723 psi | 56% | 2628 fps | 99.7% |
| SNPE Vectan Tubal 7000 | <<locked>> | 94% | 48,051 psi | 75% | 2894 fps | 95.1% |
| Somchem S321 | <<locked>> | 80% | 47,993 psi | 75% | 2959 fps | 99.7% |
| Somchem S335 | <<locked>> | 80% | 42,772 psi | 67% | 2779 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 42,250 psi | 66% | 2838 fps | 97.8% |
| Somchem S355 | <<locked>> | 80% | 34,040 psi | 53% | 2671 fps | 96% |
| Somchem S365 | <<locked>> | 86% | 29,776 psi | 47% | 2641 fps | 95.5% |
| Vihtavuori N130 | <<locked>> | 80% | 48,762 psi | 76% | 2851 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 43,366 psi | 68% | 2776 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 38,943 psi | 61% | 2756 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 39,711 psi | 62% | 2762 fps | 99.9% |
| Vihtavuori N150 | <<locked>> | 80% | 32,329 psi | 51% | 2605 fps | 96.9% |
| Vihtavuori N160 | <<locked>> | 90% | 39,624 psi | 62% | 2822 fps | 95.6% |
| Vihtavuori N530 | <<locked>> | 80% | 44,715 psi | 70% | 2874 fps | 99.3% |
| Vihtavuori N540 | <<locked>> | 80% | 38,261 psi | 60% | 2743 fps | 99.5% |
| Vihtavuori N550 | <<locked>> | 90% | 39,044 psi | 61% | 2822 fps | 95.2% |
| Vihtavuori N555 | <<locked>> | 98% | 37,130 psi | 58% | 2854 fps | 95.9% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 32,822 psi | 51% | 2625 fps | 95.5% |
| Winchester 748 | <<locked>> | 80% | 44,077 psi | 69% | 2917 fps | 99.6% |
| Winchester 760 | <<locked>> | 96% | 49,806 psi | 78% | 3064 fps | 95.7% |
| Winchester StaBALL Match | <<locked>> | 80% | 40,538 psi | 64% | 2831 fps | 98% |
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 101 powders for .25 WSSM loaded with the .257 | 100gr | Swift A-Frame. ReloadSwiss RS 60 delivers the highest muzzle velocity at 3,241 fps; across all powders the maximum-charge window runs from 1,900 fps to 3,241 fps. Accurate 4350 gives the best case fill at 100 %, and 101 of the 101 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 55–90 %, leaving at least 10 % headroom. The 100.0 gr projectile in 0.257" calls for a 1:11.5 twist; slower twists will usually not stabilise this weight. Accurate 4350, Alliant Reloder-16, Alliant Reloder-23 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. Alliant Power Pro 2000-MR, ReloadSwiss RS 60, Alliant Reloder-17 rank at the top here: for .25 WSSM with the .257 | 100gr | Swift A-Frame 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.