Load Specifications
Load data in caliber 6 mm XC with .243 | 90gr | 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-17, ReloadSwiss RS 60 and Winchester 760.
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>> | 82% | 55,042 psi | 86% | 2982 fps | 100% |
| Accurate 2495 | <<locked>> | 86% | 54,926 psi | 86% | 3018 fps | 100% |
| Accurate 2520 | <<locked>> | 82% | 55,259 psi | 87% | 3074 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 55,854 psi | 88% | 3045 fps | 96.3% |
| Accurate 4064 | <<locked>> | 88% | 54,665 psi | 86% | 3064 fps | 100% |
| Accurate 4350 | <<locked>> | 98% | 57,290 psi | 90% | 3196 fps | 99.4% |
| ADI AR 2206H | <<locked>> | 86% | 56,971 psi | 89% | 3133 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 92% | 57,682 psi | 90% | 3127 fps | 99.7% |
| ADI Benchmark 8208 | <<locked>> | 84% | 55,956 psi | 88% | 3081 fps | 100% |
| Alliant AR-Comp | <<locked>> | 84% | 56,942 psi | 89% | 3058 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 88% | 56,463 psi | 88% | 3258 fps | 99.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 90% | 54,955 psi | 86% | 3107 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 88% | 55,172 psi | 86% | 3123 fps | 99.6% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 57,246 psi | 90% | 3241 fps | 99.7% |
| Alliant Reloder-17 | <<locked>> | 94% | 55,056 psi | 86% | 3225 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 42,134 psi | 66% | 2966 fps | 98.6% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 47,050 psi | 74% | 3140 fps | 97.8% |
| Baschieri & Pellagri 107 | <<locked>> | 86% | 56,739 psi | 89% | 3146 fps | 99.4% |
| Bofors RP3 | <<locked>> | 90% | 55,767 psi | 87% | 3123 fps | 100% |
| Bofors RP7 | <<locked>> | 94% | 55,622 psi | 87% | 3084 fps | 96.5% |
| Hodgdon Benchmark | <<locked>> | 84% | 57,261 psi | 90% | 3061 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 84% | 55,680 psi | 87% | 3117 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 82% | 56,942 psi | 89% | 3212 fps | 99.7% |
| Hodgdon H380 | <<locked>> | 90% | 56,304 psi | 88% | 3130 fps | 99% |
| Hodgdon H414 | <<locked>> | 96% | 55,680 psi | 87% | 3179 fps | 97.3% |
| Hodgdon H4350 | <<locked>> | 94% | 56,014 psi | 88% | 3133 fps | 95.9% |
| Hodgdon H4895 | <<locked>> | 86% | 57,609 psi | 90% | 3146 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 53,664 psi | 84% | 3110 fps | 99.9% |
| Hodgdon LEVERevolution | <<locked>> | 88% | 56,855 psi | 89% | 3179 fps | 100% |
| Hodgdon Superformance | <<locked>> | 96% | 56,434 psi | 88% | 3215 fps | 96.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,143 psi | 57% | 1923 fps | 100% |
| Hodgdon VARGET | <<locked>> | 86% | 55,071 psi | 86% | 3091 fps | 99.9% |
| IMR 3031 | <<locked>> | 84% | 54,375 psi | 85% | 3081 fps | 100% |
| IMR 4064 | <<locked>> | 90% | 57,392 psi | 90% | 3114 fps | 99.7% |
| IMR 4166 Enduron | <<locked>> | 88% | 57,058 psi | 89% | 3084 fps | 97.3% |
| IMR 4350 | <<locked>> | 98% | 55,535 psi | 87% | 3107 fps | 96.5% |
| IMR 4451 Enduron | <<locked>> | 94% | 56,811 psi | 89% | 3110 fps | 97.2% |
| IMR 4831ᴾ | <<locked>> | 100% | 57,508 psi | 90% | 3182 fps | 99.5% |
| IMR 4895 | <<locked>> | 88% | 56,478 psi | 89% | 3156 fps | 99.9% |
| IMR 8208 XBR | <<locked>> | 84% | 55,956 psi | 88% | 3081 fps | 100% |
| Lovex D073.6 | <<locked>> | 86% | 57,319 psi | 90% | 3114 fps | 100% |
| Lovex S060 | <<locked>> | 86% | 56,101 psi | 88% | 3051 fps | 99.8% |
| Lovex S062 | <<locked>> | 88% | 54,259 psi | 85% | 3061 fps | 100% |
| Lovex S065 | <<locked>> | 96% | 57,000 psi | 89% | 3114 fps | 98.5% |
| Lovex S070 | <<locked>> | 98% | 57,696 psi | 90% | 3146 fps | 97.7% |
| Norma 201 | <<locked>> | 86% | 56,202 psi | 88% | 3081 fps | 100% |
| Norma 202 | <<locked>> | 86% | 56,391 psi | 88% | 3081 fps | 100% |
| Norma 203B | <<locked>> | 88% | 54,404 psi | 85% | 3110 fps | 99.7% |
| Norma URP | <<locked>> | 98% | 55,492 psi | 87% | 3169 fps | 99.2% |
| Ramshot Big Game | <<locked>> | 88% | 54,853 psi | 86% | 3136 fps | 99.7% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 57,725 psi | 90% | 3222 fps | 98.4% |
| Ramshot TAC | <<locked>> | 84% | 55,898 psi | 88% | 3091 fps | 98.5% |
| Ramshot Wild Boar | <<locked>> | 84% | 55,782 psi | 87% | 3117 fps | 99.8% |
| Ramshot X-Terminator | <<locked>> | 82% | 56,420 psi | 88% | 3077 fps | 99.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,477 psi | 57% | 1962 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 56,347 psi | 88% | 3107 fps | 97.8% |
| ReloadSwiss RS 52 | <<locked>> | 86% | 55,622 psi | 87% | 3196 fps | 99.6% |
| ReloadSwiss RS 60 | <<locked>> | 92% | 54,737 psi | 86% | 3225 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 98% | 56,594 psi | 89% | 3215 fps | 99.2% |
| ReloadSwiss RS 70 | <<locked>> | 98% | 55,680 psi | 87% | 3235 fps | 98.9% |
| Rottweil R 901 | <<locked>> | 84% | 57,740 psi | 90% | 3071 fps | 100% |
| Rottweil R 902 | <<locked>> | 88% | 56,724 psi | 89% | 3081 fps | 100% |
| Rottweil R 903 | <<locked>> | 92% | 55,666 psi | 87% | 3117 fps | 100% |
| Rottweil R 907 | <<locked>> | 94% | 55,622 psi | 87% | 3084 fps | 96.5% |
| Shooters World Long Rifle | <<locked>> | 96% | 57,000 psi | 89% | 3114 fps | 98.5% |
| Shooters World Match Rifle | <<locked>> | 86% | 57,319 psi | 90% | 3114 fps | 100% |
| Shooters World Precision | <<locked>> | 88% | 54,259 psi | 85% | 3061 fps | 100% |
| Shooters World SW4350 | <<locked>> | 98% | 57,696 psi | 90% | 3146 fps | 97.7% |
| SNPE Vectan SP 11 | <<locked>> | 92% | 56,681 psi | 89% | 3173 fps | 99.8% |
| SNPE Vectan SP 7 | <<locked>> | 84% | 54,723 psi | 86% | 3074 fps | 98.7% |
| SNPE Vectan SP 9 | <<locked>> | 86% | 55,347 psi | 87% | 3100 fps | 99.8% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 57,043 psi | 89% | 3009 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 57,159 psi | 90% | 3005 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 57,043 psi | 89% | 3058 fps | 97.3% |
| Somchem S321 | <<locked>> | 82% | 57,508 psi | 90% | 3120 fps | 100% |
| Somchem S335 | <<locked>> | 86% | 56,782 psi | 89% | 3012 fps | 100% |
| Somchem S341 | <<locked>> | 84% | 54,288 psi | 85% | 3064 fps | 99.7% |
| Somchem S355 | <<locked>> | 92% | 55,796 psi | 87% | 3114 fps | 99.9% |
| Somchem S365ᴾ | <<locked>> | 100% | 53,635 psi | 84% | 3182 fps | 100% |
| Vihtavuori N130 | <<locked>> | 82% | 56,753 psi | 89% | 2972 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 57,101 psi | 89% | 2992 fps | 100% |
| Vihtavuori N135 | <<locked>> | 88% | 56,231 psi | 88% | 3041 fps | 100% |
| Vihtavuori N140 | <<locked>> | 88% | 56,594 psi | 89% | 3051 fps | 100% |
| Vihtavuori N150 | <<locked>> | 94% | 57,130 psi | 90% | 3087 fps | 100% |
| Vihtavuori N160 | <<locked>> | 96% | 54,346 psi | 85% | 3110 fps | 99% |
| Vihtavuori N530 | <<locked>> | 84% | 56,159 psi | 88% | 3077 fps | 100% |
| Vihtavuori N540 | <<locked>> | 88% | 55,245 psi | 87% | 3054 fps | 100% |
| Vihtavuori N550 | <<locked>> | 98% | 57,305 psi | 90% | 3176 fps | 99.2% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 46,427 psi | 73% | 3054 fps | 98.5% |
| Winchester 6.5 StaBALL | <<locked>> | 96% | 54,389 psi | 85% | 3087 fps | 100% |
| Winchester 748 | <<locked>> | 84% | 56,246 psi | 88% | 3130 fps | 100% |
| Winchester 760 | <<locked>> | 96% | 55,680 psi | 87% | 3179 fps | 97.3% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 38,116 psi | 60% | 2972 fps | 98.5% |
| Winchester StaBALL Match | <<locked>> | 86% | 55,288 psi | 87% | 3110 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% | 51,924 psi | 81% | 2936 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 45,818 psi | 72% | 2871 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 51,837 psi | 81% | 3018 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 52,475 psi | 82% | 2986 fps | 95.5% |
| Accurate 4064 | <<locked>> | 80% | 43,192 psi | 68% | 2864 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 36,521 psi | 57% | 2782 fps | 95.1% |
| ADI AR 2206H | <<locked>> | 80% | 47,776 psi | 75% | 2969 fps | 99% |
| ADI AR 2208 | <<locked>> | 80% | 40,698 psi | 64% | 2802 fps | 97.1% |
| ADI Benchmark 8208 | <<locked>> | 80% | 49,617 psi | 78% | 2972 fps | 99.8% |
| Alliant AR-Comp | <<locked>> | 80% | 50,415 psi | 79% | 2963 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 43,482 psi | 68% | 2999 fps | 97.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 40,669 psi | 64% | 2831 fps | 98.5% |
| Alliant Reloder-15 | <<locked>> | 80% | 43,584 psi | 68% | 2900 fps | 97.9% |
| Alliant Reloder-16 | <<locked>> | 86% | 38,116 psi | 60% | 2841 fps | 95.8% |
| Alliant Reloder-17 | 35.5 gr | 80% | 35,317 psi | 55% | 2795 fps | 96.6% |
| Alliant Reloder-23 | <<locked>> | 92% | 33,489 psi | 52% | 2740 fps | 95.7% |
| Alliant Reloder-26 | <<locked>> | 94% | 38,696 psi | 61% | 2940 fps | 95% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 46,586 psi | 73% | 2963 fps | 98.1% |
| Bofors RP3 | <<locked>> | 80% | 40,799 psi | 64% | 2844 fps | 98.6% |
| Bofors RP7 | <<locked>> | 90% | 49,327 psi | 77% | 2969 fps | 95.1% |
| Hodgdon Benchmark | <<locked>> | 80% | 50,865 psi | 80% | 2953 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 49,023 psi | 77% | 3002 fps | 99.9% |
| Hodgdon CFE223 | <<locked>> | 80% | 53,287 psi | 84% | 3153 fps | 99.4% |
| Hodgdon H380 | <<locked>> | 80% | 41,365 psi | 65% | 2841 fps | 96.1% |
| Hodgdon H414 | <<locked>> | 90% | 46,108 psi | 72% | 2999 fps | 95% |
| Hodgdon H4350 | <<locked>> | 92% | 52,924 psi | 83% | 3077 fps | 95.2% |
| Hodgdon H4895 | <<locked>> | 80% | 48,240 psi | 76% | 2982 fps | 99.4% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 31,444 psi | 49% | 2621 fps | 95% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 44,193 psi | 69% | 2949 fps | 99.2% |
| Hodgdon Superformance | <<locked>> | 92% | 49,124 psi | 77% | 3081 fps | 95.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,963 psi | 42% | 1716 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 46,064 psi | 72% | 2923 fps | 99.1% |
| IMR 3031 | <<locked>> | 80% | 47,848 psi | 75% | 2972 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 42,757 psi | 67% | 2841 fps | 97.8% |
| IMR 4166 Enduron | <<locked>> | 82% | 47,601 psi | 75% | 2910 fps | 95.3% |
| IMR 4350 | <<locked>> | 94% | 49,255 psi | 77% | 2992 fps | 95.1% |
| IMR 4451 Enduron | <<locked>> | 88% | 47,732 psi | 75% | 2943 fps | 95.2% |
| IMR 4831 | <<locked>> | 86% | 37,376 psi | 59% | 2789 fps | 95.5% |
| IMR 4895 | <<locked>> | 80% | 44,628 psi | 70% | 2933 fps | 98.6% |
| IMR 8208 XBR | <<locked>> | 80% | 49,617 psi | 78% | 2972 fps | 99.8% |
| Lovex D073.6 | <<locked>> | 80% | 47,471 psi | 74% | 2953 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 47,094 psi | 74% | 2890 fps | 99% |
| Lovex S062 | <<locked>> | 80% | 42,946 psi | 67% | 2848 fps | 99.2% |
| Lovex S065 | <<locked>> | 86% | 42,554 psi | 67% | 2838 fps | 95.5% |
| Lovex S070 | <<locked>> | 90% | 45,759 psi | 72% | 2927 fps | 95.1% |
| Norma 201 | <<locked>> | 80% | 47,050 psi | 74% | 2920 fps | 99.6% |
| Norma 202 | <<locked>> | 80% | 47,152 psi | 74% | 2923 fps | 100% |
| Norma 203B | <<locked>> | 80% | 42,989 psi | 67% | 2887 fps | 98.3% |
| Norma URP | <<locked>> | 86% | 38,421 psi | 60% | 2828 fps | 95.6% |
| Ramshot Big Game | <<locked>> | 80% | 42,380 psi | 66% | 2897 fps | 98% |
| Ramshot Hunter | <<locked>> | 92% | 45,005 psi | 71% | 2986 fps | 95.7% |
| Ramshot TAC | <<locked>> | 80% | 49,414 psi | 77% | 2976 fps | 97.4% |
| Ramshot Wild Boar | <<locked>> | 80% | 49,197 psi | 77% | 3002 fps | 99.2% |
| Ramshot X-Terminator | <<locked>> | 80% | 53,040 psi | 83% | 3018 fps | 99.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,354 psi | 43% | 1755 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 44,077 psi | 69% | 2874 fps | 95.1% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 45,788 psi | 72% | 3012 fps | 98.3% |
| ReloadSwiss RS 60 | 35.5 gr | 80% | 37,391 psi | 59% | 2867 fps | 99.3% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 38,000 psi | 60% | 2848 fps | 95.2% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 40,408 psi | 63% | 2910 fps | 95.1% |
| Rottweil R 901 | <<locked>> | 80% | 51,590 psi | 81% | 2969 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 44,918 psi | 70% | 2867 fps | 99.4% |
| Rottweil R 903 | <<locked>> | 80% | 38,667 psi | 61% | 2785 fps | 97.9% |
| Rottweil R 907 | <<locked>> | 90% | 49,327 psi | 77% | 2969 fps | 95.1% |
| Shooters World Long Rifle | <<locked>> | 86% | 42,554 psi | 67% | 2838 fps | 95.5% |
| Shooters World Match Rifle | <<locked>> | 80% | 47,471 psi | 74% | 2953 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 42,946 psi | 67% | 2848 fps | 99.2% |
| Shooters World SW4350 | <<locked>> | 90% | 45,759 psi | 72% | 2927 fps | 95.1% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 39,015 psi | 61% | 2828 fps | 97.2% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 48,196 psi | 76% | 2953 fps | 97.6% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 46,137 psi | 72% | 2933 fps | 98.8% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 47,863 psi | 75% | 2861 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 40,190 psi | 63% | 2717 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 47,572 psi | 75% | 2890 fps | 95.3% |
| Somchem S321 | <<locked>> | 80% | 53,635 psi | 84% | 3058 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 47,674 psi | 75% | 2864 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 47,529 psi | 74% | 2943 fps | 99% |
| Somchem S355 | <<locked>> | 80% | 39,102 psi | 61% | 2785 fps | 97.8% |
| Somchem S365 | <<locked>> | 80% | 29,124 psi | 46% | 2612 fps | 95.5% |
| Vihtavuori N130 | <<locked>> | 80% | 53,548 psi | 84% | 2923 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 48,051 psi | 75% | 2851 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 44,324 psi | 69% | 2848 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 44,715 psi | 70% | 2854 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 37,289 psi | 58% | 2717 fps | 98.5% |
| Vihtavuori N160 | <<locked>> | 84% | 37,739 psi | 59% | 2776 fps | 95.3% |
| Vihtavuori N530 | <<locked>> | 80% | 49,632 psi | 78% | 2966 fps | 99.8% |
| Vihtavuori N540 | <<locked>> | 80% | 43,207 psi | 68% | 2841 fps | 100% |
| Vihtavuori N550 | <<locked>> | 86% | 39,624 psi | 62% | 2835 fps | 95.8% |
| Vihtavuori N555 | <<locked>> | 90% | 34,330 psi | 54% | 2776 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 32,895 psi | 52% | 2628 fps | 95.9% |
| Winchester 748 | <<locked>> | 80% | 49,400 psi | 77% | 3015 fps | 100% |
| Winchester 760 | 39.1 gr | 90% | 46,108 psi | 72% | 2999 fps | 95% |
| Winchester StaBALL HD | <<locked>> | 94% | 31,908 psi | 50% | 2769 fps | 95.2% |
| Winchester StaBALL Match | <<locked>> | 80% | 45,643 psi | 72% | 2936 fps | 99.1% |
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 6 mm XC loaded with the .243 | 90gr | Impala RNFP KO. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,258 fps; across all powders the maximum-charge window runs from 1,923 fps to 3,258 fps. Alliant Reloder-16 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 90.0 gr projectile in 0.243" calls for a 1:8.5 twist; slower twists will usually not stabilise this weight. Alliant Reloder-16, Alliant Reloder-23, Alliant Reloder-26 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-17, ReloadSwiss RS 60, Winchester 760 rank at the top here: for 6 mm XC with the .243 | 90gr | 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.