Load Specifications
Load data in caliber .255 GS with .257 | 100gr | Impala RNFP KO bullet and 94 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-16, ReloadSwiss RS 70 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.
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% | 55,970 psi | 88% | 3048 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 56,101 psi | 88% | 3074 fps | 97% |
| Accurate 3100ᴾ | <<locked>> | 100% | 49,879 psi | 78% | 3054 fps | 97.6% |
| Accurate 4064 | <<locked>> | 86% | 55,825 psi | 87% | 3097 fps | 100% |
| Accurate 4350 | <<locked>> | 94% | 55,259 psi | 87% | 3179 fps | 99.5% |
| ADI AR 2206H | <<locked>> | 84% | 57,711 psi | 90% | 3166 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 54,984 psi | 86% | 3107 fps | 99.7% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 56,028 psi | 88% | 3199 fps | 96.1% |
| ADI Benchmark 8208 | <<locked>> | 82% | 56,072 psi | 88% | 3107 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 86% | 57,377 psi | 90% | 3294 fps | 99.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 88% | 55,767 psi | 87% | 3140 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 86% | 56,130 psi | 88% | 3159 fps | 99.8% |
| Alliant Reloder-16 | <<locked>> | 96% | 55,390 psi | 87% | 3232 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 92% | 56,608 psi | 89% | 3268 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 55,201 psi | 87% | 3189 fps | 96.1% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 46,209 psi | 72% | 3071 fps | 99.7% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 52,388 psi | 82% | 3264 fps | 99.3% |
| Baschieri & Pellagri 107 | <<locked>> | 84% | 57,377 psi | 90% | 3179 fps | 99.7% |
| Bofors RP3 | <<locked>> | 88% | 56,927 psi | 89% | 3159 fps | 100% |
| Bofors RP7 | <<locked>> | 92% | 56,202 psi | 88% | 3120 fps | 97.3% |
| Hodgdon Benchmark | <<locked>> | 82% | 57,522 psi | 90% | 3087 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 82% | 56,289 psi | 88% | 3143 fps | 100% |
| Hodgdon H380 | <<locked>> | 88% | 57,203 psi | 90% | 3166 fps | 99.4% |
| Hodgdon H414 | <<locked>> | 94% | 57,159 psi | 90% | 3222 fps | 98.1% |
| Hodgdon H4350 | <<locked>> | 92% | 57,014 psi | 89% | 3176 fps | 96.8% |
| Hodgdon H4895 | <<locked>> | 82% | 54,650 psi | 86% | 3120 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 98% | 55,782 psi | 87% | 3156 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 54,404 psi | 85% | 3153 fps | 100% |
| Hodgdon Superformance | <<locked>> | 94% | 57,435 psi | 90% | 3258 fps | 97.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,201 psi | 57% | 1965 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 55,405 psi | 87% | 3117 fps | 100% |
| IMR 3031 | <<locked>> | 82% | 55,071 psi | 86% | 3107 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 54,636 psi | 86% | 3091 fps | 99.8% |
| IMR 4166 Enduron | <<locked>> | 86% | 57,319 psi | 90% | 3117 fps | 98% |
| IMR 4350 | <<locked>> | 96% | 56,478 psi | 89% | 3143 fps | 97.4% |
| IMR 4451 Enduron | <<locked>> | 92% | 57,421 psi | 90% | 3146 fps | 97.9% |
| IMR 4831 | <<locked>> | 96% | 55,651 psi | 87% | 3169 fps | 99.6% |
| IMR 4895 | <<locked>> | 86% | 57,493 psi | 90% | 3192 fps | 100% |
| IMR 8208 XBR | <<locked>> | 82% | 56,072 psi | 88% | 3107 fps | 100% |
| Lovex D073.6 | <<locked>> | 82% | 54,665 psi | 86% | 3091 fps | 100% |
| Lovex S060 | <<locked>> | 84% | 56,420 psi | 88% | 3084 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 55,114 psi | 86% | 3094 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 54,650 psi | 86% | 3097 fps | 98.6% |
| Lovex S070 | <<locked>> | 94% | 55,637 psi | 87% | 3133 fps | 98% |
| Norma 201 | <<locked>> | 84% | 56,666 psi | 89% | 3110 fps | 100% |
| Norma 202 | <<locked>> | 84% | 57,130 psi | 90% | 3110 fps | 100% |
| Norma 203B | <<locked>> | 86% | 55,405 psi | 87% | 3146 fps | 99.9% |
| Norma 204 | <<locked>> | 96% | 57,261 psi | 90% | 3199 fps | 96.3% |
| Norma MRPᴾ | <<locked>> | 100% | 51,706 psi | 81% | 3209 fps | 97% |
| Norma URP | <<locked>> | 96% | 57,058 psi | 89% | 3212 fps | 99.6% |
| Ramshot Big Game | <<locked>> | 86% | 55,811 psi | 87% | 3166 fps | 99.9% |
| Ramshot Hunter | <<locked>> | 96% | 55,883 psi | 88% | 3209 fps | 98.6% |
| Ramshot TAC | <<locked>> | 82% | 56,492 psi | 89% | 3127 fps | 99% |
| Ramshot Wild Boar | <<locked>> | 82% | 56,188 psi | 88% | 3146 fps | 99.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,028 psi | 58% | 2018 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 57,246 psi | 90% | 3146 fps | 98.5% |
| ReloadSwiss RS 52 | <<locked>> | 84% | 56,724 psi | 89% | 3232 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 90% | 56,463 psi | 88% | 3271 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 54,781 psi | 86% | 3196 fps | 99.4% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 57,014 psi | 89% | 3278 fps | 99.5% |
| Rottweil R 902 | <<locked>> | 86% | 57,319 psi | 90% | 3110 fps | 100% |
| Rottweil R 903 | <<locked>> | 90% | 57,043 psi | 89% | 3156 fps | 100% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 54,317 psi | 85% | 3173 fps | 96.1% |
| Rottweil R 907 | <<locked>> | 92% | 56,202 psi | 88% | 3120 fps | 97.3% |
| Shooters World Long Rifle | <<locked>> | 92% | 54,650 psi | 86% | 3097 fps | 98.6% |
| Shooters World Match Rifle | <<locked>> | 82% | 54,665 psi | 86% | 3091 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 55,114 psi | 86% | 3094 fps | 100% |
| Shooters World SW4350 | <<locked>> | 94% | 55,637 psi | 87% | 3133 fps | 98% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 54,288 psi | 85% | 3150 fps | 99.9% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 55,390 psi | 87% | 3107 fps | 99.2% |
| SNPE Vectan SP 9 | <<locked>> | 84% | 55,941 psi | 88% | 3133 fps | 99.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 84% | 57,334 psi | 90% | 3038 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 90% | 57,667 psi | 90% | 3031 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 54,447 psi | 85% | 3041 fps | 97.5% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 53,809 psi | 84% | 3166 fps | 96% |
| Somchem S335 | <<locked>> | 84% | 57,087 psi | 89% | 3035 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 54,926 psi | 86% | 3097 fps | 99.9% |
| Somchem S355 | <<locked>> | 90% | 56,884 psi | 89% | 3146 fps | 100% |
| Somchem S365 | <<locked>> | 98% | 55,637 psi | 87% | 3219 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 55,143 psi | 86% | 3150 fps | 97.1% |
| Vihtavuori N133 | <<locked>> | 84% | 57,522 psi | 90% | 3018 fps | 100% |
| Vihtavuori N135 | <<locked>> | 86% | 57,246 psi | 90% | 3071 fps | 100% |
| Vihtavuori N140 | <<locked>> | 86% | 57,406 psi | 90% | 3081 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 54,679 psi | 86% | 3068 fps | 100% |
| Vihtavuori N160 | <<locked>> | 94% | 55,738 psi | 87% | 3150 fps | 99.5% |
| Vihtavuori N530 | <<locked>> | 82% | 56,710 psi | 89% | 3107 fps | 100% |
| Vihtavuori N540 | <<locked>> | 86% | 55,854 psi | 88% | 3077 fps | 100% |
| Vihtavuori N550 | <<locked>> | 94% | 55,259 psi | 87% | 3159 fps | 99.4% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 51,532 psi | 81% | 3159 fps | 99.6% |
| Winchester 6.5 StaBALL | <<locked>> | 94% | 55,550 psi | 87% | 3120 fps | 100% |
| Winchester 748 | <<locked>> | 82% | 57,014 psi | 89% | 3159 fps | 100% |
| Winchester 760 | <<locked>> | 94% | 57,421 psi | 90% | 3225 fps | 98.1% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 41,989 psi | 66% | 3104 fps | 99.8% |
| Winchester StaBALL Match | <<locked>> | 84% | 55,869 psi | 88% | 3140 fps | 100% |
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% | 49,588 psi | 78% | 2949 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 49,632 psi | 78% | 2963 fps | 95.7% |
| Accurate 3100 | <<locked>> | 94% | 40,843 psi | 64% | 2874 fps | 95.3% |
| Accurate 4064 | <<locked>> | 80% | 46,862 psi | 73% | 2946 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 35,244 psi | 55% | 2766 fps | 95.3% |
| ADI AR 2206H | <<locked>> | 80% | 51,053 psi | 80% | 3054 fps | 99.7% |
| ADI AR 2208 | <<locked>> | 80% | 43,511 psi | 68% | 2887 fps | 98.2% |
| ADI AR 2209 | <<locked>> | 98% | 52,402 psi | 82% | 3133 fps | 95.2% |
| ADI Benchmark 8208 | <<locked>> | 80% | 52,895 psi | 83% | 3054 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 46,934 psi | 74% | 3100 fps | 98.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 43,845 psi | 69% | 2920 fps | 99.4% |
| Alliant Reloder-15 | <<locked>> | 80% | 46,789 psi | 73% | 2989 fps | 98.9% |
| Alliant Reloder-16 | 41.3 gr | 82% | 36,376 psi | 57% | 2818 fps | 95.9% |
| Alliant Reloder-17 | <<locked>> | 80% | 38,290 psi | 60% | 2897 fps | 98.2% |
| Alliant Reloder-19 | <<locked>> | 98% | 51,663 psi | 81% | 3123 fps | 95.3% |
| Alliant Reloder-23 | <<locked>> | 86% | 30,647 psi | 48% | 2674 fps | 95.1% |
| Alliant Reloder-26 | <<locked>> | 90% | 37,507 psi | 59% | 2927 fps | 95.5% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 50,531 psi | 79% | 3058 fps | 99.1% |
| Bofors RP3 | <<locked>> | 80% | 44,469 psi | 70% | 2940 fps | 99.5% |
| Bofors RP7 | <<locked>> | 86% | 47,094 psi | 74% | 2949 fps | 95.2% |
| Hodgdon Benchmark | <<locked>> | 80% | 54,302 psi | 85% | 3035 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 52,779 psi | 83% | 3087 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 44,614 psi | 70% | 2933 fps | 97.5% |
| Hodgdon H414 | <<locked>> | 86% | 44,440 psi | 70% | 2982 fps | 95.2% |
| Hodgdon H4350 | <<locked>> | 88% | 50,430 psi | 79% | 3058 fps | 95.3% |
| Hodgdon H4895 | <<locked>> | 80% | 51,576 psi | 81% | 3064 fps | 99.9% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 32,126 psi | 50% | 2664 fps | 96.1% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 47,674 psi | 75% | 3035 fps | 99.8% |
| Hodgdon Superformance | 50.5 gr | 88% | 46,833 psi | 73% | 3054 fps | 95.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,340 psi | 43% | 1765 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 49,269 psi | 77% | 3009 fps | 99.7% |
| IMR 3031 | <<locked>> | 80% | 51,692 psi | 81% | 3054 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 45,730 psi | 72% | 2927 fps | 98.8% |
| IMR 4166 Enduron | <<locked>> | 80% | 47,906 psi | 75% | 2946 fps | 96.1% |
| IMR 4350 | <<locked>> | 90% | 47,123 psi | 74% | 2972 fps | 95.3% |
| IMR 4451 Enduron | <<locked>> | 84% | 45,600 psi | 71% | 2927 fps | 95.4% |
| IMR 4831 | <<locked>> | 82% | 36,114 psi | 57% | 2772 fps | 95.7% |
| IMR 4895 | <<locked>> | 80% | 47,935 psi | 75% | 3022 fps | 99.4% |
| IMR 8208 XBR | <<locked>> | 80% | 52,895 psi | 83% | 3054 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 51,474 psi | 81% | 3038 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 50,256 psi | 79% | 2976 fps | 99.6% |
| Lovex S062 | <<locked>> | 80% | 46,253 psi | 72% | 2936 fps | 99.8% |
| Lovex S065 | <<locked>> | 82% | 40,785 psi | 64% | 2822 fps | 95.6% |
| Lovex S070 | <<locked>> | 86% | 43,859 psi | 69% | 2910 fps | 95.3% |
| Norma 201 | <<locked>> | 80% | 50,444 psi | 79% | 3005 fps | 100% |
| Norma 202 | <<locked>> | 80% | 50,488 psi | 79% | 3005 fps | 100% |
| Norma 203B | <<locked>> | 80% | 46,195 psi | 72% | 2976 fps | 99.2% |
| Norma 204 | <<locked>> | 94% | 53,534 psi | 84% | 3133 fps | 95.5% |
| Norma MRP | <<locked>> | 96% | 45,310 psi | 71% | 3074 fps | 95.2% |
| Norma URP | <<locked>> | 80% | 34,954 psi | 55% | 2756 fps | 95% |
| Ramshot Big Game | <<locked>> | 80% | 45,890 psi | 72% | 2989 fps | 99.1% |
| Ramshot Hunter | <<locked>> | 86% | 40,872 psi | 64% | 2910 fps | 95.1% |
| Ramshot TAC | <<locked>> | 80% | 52,823 psi | 83% | 3064 fps | 98.5% |
| Ramshot Wild Boar | <<locked>> | 80% | 52,721 psi | 83% | 3087 fps | 99.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,659 psi | 43% | 1804 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 44,701 psi | 70% | 2910 fps | 96% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 49,893 psi | 78% | 3114 fps | 99.3% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 40,509 psi | 63% | 2966 fps | 99.9% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 36,941 psi | 58% | 2835 fps | 95.5% |
| ReloadSwiss RS 70 | 46.3 gr | 84% | 38,551 psi | 60% | 2890 fps | 95.3% |
| Rottweil R 902 | <<locked>> | 80% | 48,124 psi | 75% | 2953 fps | 99.9% |
| Rottweil R 903 | <<locked>> | 80% | 42,018 psi | 66% | 2881 fps | 99% |
| Rottweil R 905 | <<locked>> | 98% | 50,734 psi | 80% | 3110 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 86% | 47,094 psi | 74% | 2949 fps | 95.2% |
| Shooters World Long Rifle | <<locked>> | 82% | 40,785 psi | 64% | 2822 fps | 95.6% |
| Shooters World Match Rifle | <<locked>> | 80% | 51,474 psi | 81% | 3038 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 46,253 psi | 72% | 2936 fps | 99.8% |
| Shooters World SW4350 | <<locked>> | 86% | 43,859 psi | 69% | 2910 fps | 95.3% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 42,380 psi | 66% | 2923 fps | 98.5% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 51,909 psi | 81% | 3045 fps | 98.8% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 49,588 psi | 78% | 3018 fps | 99.6% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 51,126 psi | 80% | 2940 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 43,163 psi | 68% | 2799 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 45,310 psi | 71% | 2871 fps | 95.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 50,241 psi | 79% | 3100 fps | 95.1% |
| Somchem S335 | <<locked>> | 80% | 50,908 psi | 80% | 2940 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 51,474 psi | 81% | 3038 fps | 99.7% |
| Somchem S355 | <<locked>> | 80% | 42,206 psi | 66% | 2874 fps | 98.9% |
| Somchem S365 | <<locked>> | 80% | 31,647 psi | 50% | 2710 fps | 97.4% |
| Somchem S385 | <<locked>> | 96% | 48,646 psi | 76% | 3035 fps | 95.7% |
| Vihtavuori N133 | <<locked>> | 80% | 51,358 psi | 80% | 2927 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 47,935 psi | 75% | 2930 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 48,080 psi | 75% | 2933 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 40,335 psi | 63% | 2805 fps | 99.4% |
| Vihtavuori N160 | <<locked>> | 80% | 36,114 psi | 57% | 2753 fps | 95.4% |
| Vihtavuori N530 | <<locked>> | 80% | 53,403 psi | 84% | 3054 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 46,427 psi | 73% | 2923 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 35,810 psi | 56% | 2756 fps | 95.1% |
| Vihtavuori N555 | <<locked>> | 86% | 33,388 psi | 52% | 2762 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 35,636 psi | 56% | 2723 fps | 97.6% |
| Winchester 748 | <<locked>> | 80% | 53,388 psi | 84% | 3104 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 44,440 psi | 70% | 2982 fps | 95.2% |
| Winchester StaBALL HD | <<locked>> | 90% | 31,024 psi | 49% | 2766 fps | 95.9% |
| Winchester StaBALL Match | <<locked>> | 80% | 49,414 psi | 77% | 3028 fps | 99.8% |
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 94 powders for .255 GS loaded with the .257 | 100gr | Impala RNFP KO. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,294 fps; across all powders the maximum-charge window runs from 1,965 fps to 3,294 fps. Accurate 3100 gives the best case fill at 100 %, and 94 of the 94 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 100.0 gr projectile in 0.257" calls for a 1:10.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2209, Alliant Reloder-19 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 Reloder-16, ReloadSwiss RS 70, Hodgdon Superformance rank at the top here: for .255 GS with the .257 | 100gr | Impala RNFP KO 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.