Load Specifications
Bullet Manufacturer:Peregrine
Bullet Weight:87 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:1:9.0
Load data in caliber .255 GS with .257 | 87gr | Peregrine Plainsmaster (VLR-4) bullet and 100 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.
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 2015 | <<locked>> | 86% | 55,695 psi | 87% | 3241 fps | 100% |
| Accurate 2460 | <<locked>> | 82% | 54,157 psi | 85% | 3261 fps | 100% |
| Accurate 2495 | <<locked>> | 92% | 57,551 psi | 90% | 3307 fps | 100% |
| Accurate 2520 | <<locked>> | 86% | 54,766 psi | 86% | 3314 fps | 100% |
| Accurate 2520 | <<locked>> | 86% | 54,766 psi | 86% | 3314 fps | 100% |
| Accurate 4064 | <<locked>> | 94% | 57,450 psi | 90% | 3353 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 54,201 psi | 85% | 3369 fps | 98.6% |
| ADI AR 2206H | <<locked>> | 88% | 55,158 psi | 86% | 3340 fps | 99.4% |
| ADI AR 2208 | <<locked>> | 94% | 56,072 psi | 88% | 3330 fps | 99.2% |
| ADI Benchmark 8208 | <<locked>> | 86% | 54,012 psi | 85% | 3287 fps | 99.8% |
| Alliant AR-Comp | <<locked>> | 86% | 54,636 psi | 86% | 3274 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 82% | 55,840 psi | 88% | 3415 fps | 99.7% |
| Alliant Power Pro 2000-MR | <<locked>> | 90% | 55,187 psi | 86% | 3465 fps | 99.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 94% | 56,086 psi | 88% | 3360 fps | 99.9% |
| Alliant Reloder-10x | <<locked>> | 82% | 54,984 psi | 86% | 3248 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 92% | 56,536 psi | 89% | 3383 fps | 99.3% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 52,156 psi | 82% | 3373 fps | 98.6% |
| Alliant Reloder-17 | <<locked>> | 98% | 57,319 psi | 90% | 3488 fps | 99.9% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 37,057 psi | 58% | 3041 fps | 96.1% |
| Baschieri & Pellagri 106 | <<locked>> | 82% | 57,696 psi | 90% | 3222 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 88% | 55,027 psi | 86% | 3346 fps | 98.8% |
| Bofors RP3 | <<locked>> | 94% | 56,666 psi | 89% | 3373 fps | 99.9% |
| Bofors RP7 | <<locked>> | 98% | 56,985 psi | 89% | 3330 fps | 95.9% |
| Hodgdon Benchmark | <<locked>> | 86% | 56,101 psi | 88% | 3278 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 88% | 57,116 psi | 90% | 3373 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 84% | 55,376 psi | 87% | 3422 fps | 99.2% |
| Hodgdon H322 | <<locked>> | 86% | 57,479 psi | 90% | 3337 fps | 100% |
| Hodgdon H380 | <<locked>> | 92% | 54,244 psi | 85% | 3323 fps | 98.1% |
| Hodgdon H414 | <<locked>> | 96% | 55,637 psi | 87% | 3399 fps | 96.5% |
| Hodgdon H4895 | <<locked>> | 88% | 55,709 psi | 87% | 3353 fps | 99.7% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 48,341 psi | 76% | 3238 fps | 99% |
| Hodgdon LEVERevolution | <<locked>> | 92% | 55,172 psi | 86% | 3383 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,954 psi | 55% | 2093 fps | 100% |
| Hodgdon VARGET | <<locked>> | 92% | 55,869 psi | 88% | 3337 fps | 99.7% |
| IMR 3031 | <<locked>> | 92% | 57,043 psi | 89% | 3369 fps | 100% |
| IMR 4064 | <<locked>> | 94% | 54,781 psi | 86% | 3301 fps | 99.1% |
| IMR 4166 Enduron | <<locked>> | 94% | 54,346 psi | 85% | 3261 fps | 96% |
| IMR 4198 | <<locked>> | 82% | 55,463 psi | 87% | 3215 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 96% | 55,521 psi | 87% | 3307 fps | 96.2% |
| IMR 4831ᴾ | <<locked>> | 100% | 45,310 psi | 71% | 3179 fps | 97% |
| IMR 4895 | <<locked>> | 90% | 54,447 psi | 85% | 3356 fps | 99.4% |
| IMR 8208 XBR | <<locked>> | 86% | 54,012 psi | 85% | 3287 fps | 99.8% |
| Lovex D073.5 | <<locked>> | 82% | 54,201 psi | 85% | 3271 fps | 100% |
| Lovex D073.6 | <<locked>> | 88% | 54,766 psi | 86% | 3314 fps | 100% |
| Lovex S060 | <<locked>> | 88% | 54,679 psi | 86% | 3261 fps | 99.4% |
| Lovex S062 | <<locked>> | 92% | 55,042 psi | 86% | 3310 fps | 99.9% |
| Lovex S065 | <<locked>> | 98% | 54,737 psi | 86% | 3301 fps | 97.5% |
| Lovex S070ᴾ | <<locked>> | 100% | 55,463 psi | 87% | 3330 fps | 96.6% |
| Norma 201 | <<locked>> | 90% | 57,159 psi | 90% | 3337 fps | 100% |
| Norma 202 | <<locked>> | 90% | 57,653 psi | 90% | 3340 fps | 100% |
| Norma 203B | <<locked>> | 92% | 55,695 psi | 87% | 3363 fps | 99.5% |
| Norma URPᴾ | <<locked>> | 100% | 53,287 psi | 84% | 3356 fps | 98.4% |
| Ramshot Big Game | <<locked>> | 92% | 57,043 psi | 89% | 3399 fps | 99.6% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 52,518 psi | 82% | 3343 fps | 96.7% |
| Ramshot TAC | <<locked>> | 86% | 54,621 psi | 86% | 3297 fps | 97.7% |
| Ramshot Wild Boar | <<locked>> | 86% | 54,172 psi | 85% | 3320 fps | 99.3% |
| Ramshot X-Terminator | <<locked>> | 84% | 55,100 psi | 86% | 3284 fps | 99.3% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,201 psi | 55% | 2139 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 84% | 57,014 psi | 89% | 3327 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 92% | 54,853 psi | 86% | 3304 fps | 96.8% |
| ReloadSwiss RS 52 | <<locked>> | 90% | 57,203 psi | 90% | 3458 fps | 99.3% |
| ReloadSwiss RS 60 | <<locked>> | 96% | 57,334 psi | 90% | 3501 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 54,215 psi | 85% | 3396 fps | 98.4% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 54,375 psi | 85% | 3422 fps | 98.1% |
| Rottweil R 901 | <<locked>> | 88% | 57,711 psi | 90% | 3323 fps | 100% |
| Rottweil R 902 | <<locked>> | 92% | 57,435 psi | 90% | 3330 fps | 100% |
| Rottweil R 903 | <<locked>> | 96% | 56,492 psi | 89% | 3363 fps | 99.8% |
| Rottweil R 907 | <<locked>> | 98% | 56,985 psi | 89% | 3330 fps | 95.9% |
| Shooters World Long Rifle | <<locked>> | 98% | 54,737 psi | 86% | 3301 fps | 97.5% |
| Shooters World Match Rifle | <<locked>> | 88% | 54,766 psi | 86% | 3314 fps | 100% |
| Shooters World Precision | <<locked>> | 92% | 55,042 psi | 86% | 3310 fps | 99.9% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 55,463 psi | 87% | 3330 fps | 96.6% |
| Shooters World Tactical Rifle | <<locked>> | 82% | 56,782 psi | 89% | 3294 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 94% | 55,042 psi | 86% | 3369 fps | 99.4% |
| SNPE Vectan SP 3 | <<locked>> | 82% | 56,072 psi | 88% | 3278 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 88% | 56,739 psi | 89% | 3333 fps | 98.4% |
| SNPE Vectan SP 9 | <<locked>> | 90% | 57,188 psi | 90% | 3363 fps | 99.6% |
| SNPE Vectan Tubal 3000 | <<locked>> | 88% | 55,448 psi | 87% | 3225 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 94% | 55,579 psi | 87% | 3215 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 98% | 55,347 psi | 87% | 3248 fps | 96.2% |
| Somchem S321 | <<locked>> | 84% | 55,434 psi | 87% | 3323 fps | 100% |
| Somchem S335 | <<locked>> | 88% | 54,694 psi | 86% | 3219 fps | 100% |
| Somchem S341 | <<locked>> | 88% | 56,173 psi | 88% | 3323 fps | 99.5% |
| Somchem S355 | <<locked>> | 96% | 56,666 psi | 89% | 3360 fps | 99.8% |
| Somchem S365ᴾ | <<locked>> | 100% | 47,645 psi | 75% | 3297 fps | 99.8% |
| Unknown powder | <<locked>> | 98% | 54,766 psi | 86% | 3376 fps | 98.1% |
| Vihtavuori N130 | <<locked>> | 84% | 54,926 psi | 86% | 3189 fps | 100% |
| Vihtavuori N133 | <<locked>> | 88% | 55,622 psi | 87% | 3212 fps | 100% |
| Vihtavuori N135 | <<locked>> | 92% | 56,985 psi | 89% | 3297 fps | 100% |
| Vihtavuori N140 | <<locked>> | 90% | 54,882 psi | 86% | 3264 fps | 100% |
| Vihtavuori N150 | <<locked>> | 96% | 54,998 psi | 86% | 3284 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 56,188 psi | 88% | 3360 fps | 98.7% |
| Vihtavuori N530 | <<locked>> | 86% | 54,607 psi | 86% | 3287 fps | 99.9% |
| Vihtavuori N540 | <<locked>> | 92% | 56,855 psi | 89% | 3310 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 55,114 psi | 86% | 3360 fps | 98.5% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 40,089 psi | 63% | 3130 fps | 96.2% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 57,101 psi | 89% | 3340 fps | 99.9% |
| Winchester 748 | <<locked>> | 84% | 55,143 psi | 86% | 3350 fps | 100% |
| Winchester 760 | <<locked>> | 96% | 55,637 psi | 87% | 3399 fps | 96.5% |
| Winchester StaBALL Match | <<locked>> | 82% | 54,984 psi | 86% | 3333 fps | 99.7% |
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% | 45,861 psi | 72% | 3077 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 50,459 psi | 79% | 3199 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 38,087 psi | 60% | 2959 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 44,092 psi | 69% | 3120 fps | 99.7% |
| Accurate 2520 | <<locked>> | 80% | 44,092 psi | 69% | 3120 fps | 99.7% |
| Accurate 4064 | <<locked>> | 80% | 36,056 psi | 56% | 2940 fps | 99.1% |
| Accurate 4350 | <<locked>> | 92% | 40,335 psi | 63% | 3091 fps | 95.4% |
| ADI AR 2206H | <<locked>> | 80% | 42,351 psi | 66% | 3081 fps | 97.3% |
| ADI AR 2208 | <<locked>> | 82% | 38,377 psi | 60% | 2966 fps | 95.3% |
| ADI Benchmark 8208 | <<locked>> | 80% | 44,469 psi | 70% | 3104 fps | 98.8% |
| Alliant AR-Comp | <<locked>> | 80% | 44,469 psi | 70% | 3110 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 51,967 psi | 81% | 3343 fps | 99.4% |
| Alliant Power Pro 2000-MR | 45.3 gr | 82% | 41,278 psi | 65% | 3163 fps | 95.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 35,259 psi | 55% | 2920 fps | 96.1% |
| Alliant Reloder-10x | <<locked>> | 80% | 51,866 psi | 81% | 3196 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 38,072 psi | 60% | 2992 fps | 95.4% |
| Alliant Reloder-16 | <<locked>> | 92% | 40,437 psi | 63% | 3110 fps | 95.5% |
| Alliant Reloder-17 | 45.7 gr | 84% | 35,070 psi | 55% | 2992 fps | 95.3% |
| Alliant Reloder-23 | <<locked>> | 98% | 34,766 psi | 54% | 2972 fps | 95% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 54,056 psi | 85% | 3166 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 41,800 psi | 66% | 3077 fps | 96% |
| Bofors RP3 | <<locked>> | 80% | 34,867 psi | 55% | 2920 fps | 96.1% |
| Bofors RP7 | <<locked>> | 96% | 53,447 psi | 84% | 3268 fps | 95.2% |
| Hodgdon Benchmark | <<locked>> | 80% | 46,369 psi | 73% | 3100 fps | 99.4% |
| Hodgdon BL-C2 | <<locked>> | 80% | 43,149 psi | 68% | 3114 fps | 99% |
| Hodgdon CFE223 | <<locked>> | 80% | 48,008 psi | 75% | 3284 fps | 98.1% |
| Hodgdon H322 | <<locked>> | 80% | 47,239 psi | 74% | 3163 fps | 100% |
| Hodgdon H380 | <<locked>> | 84% | 41,089 psi | 64% | 3054 fps | 95% |
| Hodgdon H414 | <<locked>> | 94% | 51,793 psi | 81% | 3327 fps | 95.6% |
| Hodgdon H4895 | <<locked>> | 80% | 42,699 psi | 67% | 3097 fps | 97.9% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 34,679 psi | 54% | 2920 fps | 95.3% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 36,405 psi | 57% | 2989 fps | 96.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,889 psi | 41% | 1873 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 38,130 psi | 60% | 2969 fps | 96.6% |
| IMR 3031 | <<locked>> | 80% | 38,435 psi | 60% | 3025 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 37,507 psi | 59% | 2940 fps | 95.3% |
| IMR 4166 Enduron | <<locked>> | 92% | 51,111 psi | 80% | 3202 fps | 95.2% |
| IMR 4198 | <<locked>> | 80% | 51,967 psi | 81% | 3159 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 94% | 52,170 psi | 82% | 3248 fps | 95.4% |
| IMR 4831 | <<locked>> | 96% | 39,682 psi | 62% | 3054 fps | 95.3% |
| IMR 4895 | <<locked>> | 80% | 38,986 psi | 61% | 3031 fps | 96.4% |
| IMR 8208 XBR | <<locked>> | 80% | 44,469 psi | 70% | 3104 fps | 98.8% |
| Lovex D073.5 | <<locked>> | 80% | 50,198 psi | 79% | 3202 fps | 99.9% |
| Lovex D073.6 | <<locked>> | 80% | 41,263 psi | 65% | 3058 fps | 99.3% |
| Lovex S060 | <<locked>> | 80% | 42,670 psi | 67% | 3025 fps | 97.5% |
| Lovex S062 | <<locked>> | 80% | 37,507 psi | 59% | 2949 fps | 97.3% |
| Lovex S065 | <<locked>> | 92% | 45,078 psi | 71% | 3110 fps | 95.2% |
| Lovex S070 | <<locked>> | 96% | 48,849 psi | 77% | 3209 fps | 95% |
| Norma 201 | <<locked>> | 80% | 41,321 psi | 65% | 3031 fps | 98.2% |
| Norma 202 | <<locked>> | 80% | 41,611 psi | 65% | 3048 fps | 99.7% |
| Norma 203B | <<locked>> | 80% | 37,449 psi | 59% | 2982 fps | 95.8% |
| Norma URP | <<locked>> | 92% | 40,640 psi | 64% | 3094 fps | 95.3% |
| Ramshot Big Game | <<locked>> | 80% | 37,057 psi | 58% | 2989 fps | 95.5% |
| Ramshot Hunter | <<locked>> | 98% | 48,965 psi | 77% | 3278 fps | 95.8% |
| Ramshot TAC | <<locked>> | 80% | 44,715 psi | 70% | 3097 fps | 95.3% |
| Ramshot Wild Boar | <<locked>> | 80% | 44,092 psi | 69% | 3123 fps | 97.7% |
| Ramshot X-Terminator | <<locked>> | 80% | 48,240 psi | 76% | 3156 fps | 98.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,194 psi | 41% | 1919 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 49,966 psi | 78% | 3209 fps | 99.9% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 47,805 psi | 75% | 3169 fps | 95.1% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 39,987 psi | 63% | 3110 fps | 95.9% |
| ReloadSwiss RS 60 | 43.5 gr | 80% | 32,489 psi | 51% | 2930 fps | 96.8% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 40,393 psi | 63% | 3114 fps | 95% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 43,990 psi | 69% | 3202 fps | 95.3% |
| Rottweil R 901 | <<locked>> | 80% | 44,904 psi | 70% | 3094 fps | 99.9% |
| Rottweil R 902 | <<locked>> | 80% | 39,189 psi | 61% | 2972 fps | 97.7% |
| Rottweil R 903 | <<locked>> | 82% | 34,969 psi | 55% | 2917 fps | 95.8% |
| Rottweil R 907 | <<locked>> | 96% | 53,447 psi | 84% | 3268 fps | 95.2% |
| Shooters World Long Rifle | <<locked>> | 92% | 45,078 psi | 71% | 3110 fps | 95.2% |
| Shooters World Match Rifle | <<locked>> | 80% | 41,263 psi | 65% | 3058 fps | 99.3% |
| Shooters World Precision | <<locked>> | 80% | 37,507 psi | 59% | 2949 fps | 97.3% |
| Shooters World SW4350 | <<locked>> | 96% | 48,849 psi | 77% | 3209 fps | 95% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 52,953 psi | 83% | 3228 fps | 99.6% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 36,245 psi | 57% | 2972 fps | 95.2% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 52,881 psi | 83% | 3225 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 42,554 psi | 67% | 3058 fps | 95.3% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 41,075 psi | 64% | 3045 fps | 96.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 42,975 psi | 67% | 3002 fps | 99.8% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 35,563 psi | 56% | 2838 fps | 99.4% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 51,488 psi | 81% | 3176 fps | 95.4% |
| Somchem S321 | <<locked>> | 80% | 48,327 psi | 76% | 3196 fps | 99.5% |
| Somchem S335 | <<locked>> | 80% | 42,409 psi | 66% | 2995 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 42,525 psi | 67% | 3064 fps | 97.3% |
| Somchem S355 | <<locked>> | 82% | 35,868 psi | 56% | 2927 fps | 95.9% |
| Somchem S365 | <<locked>> | 88% | 31,575 psi | 49% | 2894 fps | 95.5% |
| Unknown powder | <<locked>> | 92% | 44,411 psi | 70% | 3169 fps | 95.7% |
| Vihtavuori N130 | <<locked>> | 80% | 48,675 psi | 76% | 3087 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 43,337 psi | 68% | 3005 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 38,682 psi | 61% | 2972 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 39,566 psi | 62% | 2976 fps | 99.6% |
| Vihtavuori N150 | <<locked>> | 80% | 32,039 psi | 50% | 2799 fps | 96% |
| Vihtavuori N160 | <<locked>> | 90% | 39,885 psi | 63% | 3038 fps | 95% |
| Vihtavuori N530 | <<locked>> | 80% | 44,672 psi | 70% | 3100 fps | 98.9% |
| Vihtavuori N540 | <<locked>> | 80% | 38,000 psi | 60% | 2953 fps | 99.2% |
| Vihtavuori N550 | <<locked>> | 92% | 42,090 psi | 66% | 3100 fps | 95.5% |
| Vihtavuori N555 | <<locked>> | 98% | 37,449 psi | 59% | 3064 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 35,114 psi | 55% | 2887 fps | 95.7% |
| Winchester 748 | <<locked>> | 80% | 47,877 psi | 75% | 3222 fps | 99.7% |
| Winchester 760 | <<locked>> | 94% | 51,793 psi | 81% | 3327 fps | 95.6% |
| Winchester StaBALL Match | <<locked>> | 80% | 50,966 psi | 80% | 3264 fps | 99.3% |
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 100 powders for .255 GS loaded with the .257 | 87gr | Peregrine Plainsmaster (VLR-4). ReloadSwiss RS 60 delivers the highest muzzle velocity at 3,501 fps; across all powders the maximum-charge window runs from 2,093 fps to 3,501 fps. Accurate 4350 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 55–90 %, leaving at least 10 % headroom. The 87.0 gr projectile in 0.257" calls for a 1:9.0 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 .255 GS with the .257 | 87gr | Peregrine Plainsmaster (VLR-4) 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.