Load Specifications
Bullet Manufacturer:Sierra
Bullet Weight:168 gr
Bullet Diameter:0.308"
Bullet Length:<<locked>>
Caliber:.300 H&H Mag. load data
Case Length (l3):2.85"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:85.9 Grains of Water
Primer Size:Large Rifle Magnum (LRM)
Barrel Length:24"
Max. allowed Pressure:62,366 psi
Recommended Twist Rate:1:13.5
Load data in caliber .300 H&H Mag. with .308 | 168gr | Sierra MatchKing bullet and 94 powders. The key underlying parameters are shown in the table above.
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% | 55,201 psi | 89% | 2802 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 53,229 psi | 85% | 2812 fps | 97.7% |
| Accurate 3100ᴾ | <<locked>> | 100% | 49,792 psi | 80% | 2838 fps | 98.6% |
| Accurate 4064 | <<locked>> | 86% | 55,521 psi | 89% | 2858 fps | 100% |
| Accurate 4350 | <<locked>> | 94% | 55,999 psi | 90% | 2956 fps | 99.9% |
| Accurate High Countryᴾ | <<locked>> | 100% | 54,404 psi | 87% | 3035 fps | 96.4% |
| ADI AR 2206H | <<locked>> | 82% | 54,795 psi | 88% | 2884 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 55,869 psi | 90% | 2887 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 53,374 psi | 86% | 2933 fps | 96.9% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 54,955 psi | 88% | 3012 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 88% | 56,434 psi | 90% | 2910 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 53,345 psi | 86% | 2881 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 53,040 psi | 85% | 2956 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 90% | 54,375 psi | 87% | 2989 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 56,101 psi | 90% | 2979 fps | 97.6% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 49,661 psi | 80% | 2913 fps | 96.4% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 46,847 psi | 75% | 2861 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 40,930 psi | 66% | 2766 fps | 97.4% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 53,679 psi | 86% | 3054 fps | 99.9% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 54,592 psi | 88% | 2900 fps | 99.9% |
| Bofors RP3 | <<locked>> | 86% | 53,780 psi | 86% | 2877 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 49,661 psi | 80% | 2913 fps | 96.4% |
| Bofors RP7 | <<locked>> | 90% | 53,461 psi | 86% | 2854 fps | 97.9% |
| Hodgdon H380 | <<locked>> | 86% | 54,186 psi | 87% | 2887 fps | 99.7% |
| Hodgdon H414 | <<locked>> | 92% | 54,708 psi | 88% | 2953 fps | 98.7% |
| Hodgdon H4350 | <<locked>> | 90% | 54,607 psi | 88% | 2910 fps | 97.6% |
| Hodgdon H4895 | <<locked>> | 82% | 55,390 psi | 89% | 2894 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 53,374 psi | 86% | 2884 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 55,259 psi | 89% | 2927 fps | 100% |
| Hodgdon Superformance | <<locked>> | 92% | 54,897 psi | 88% | 2989 fps | 98.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,143 psi | 58% | 1798 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 56,420 psi | 90% | 2894 fps | 100% |
| IMR 3031 | <<locked>> | 82% | 55,840 psi | 90% | 2871 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 55,274 psi | 89% | 2867 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 54,766 psi | 88% | 2851 fps | 98.6% |
| IMR 4350 | <<locked>> | 94% | 54,012 psi | 87% | 2881 fps | 98.1% |
| IMR 4451 Enduron | <<locked>> | 90% | 55,085 psi | 88% | 2881 fps | 98.6% |
| IMR 4831 | <<locked>> | 96% | 56,434 psi | 90% | 2946 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 54,723 psi | 88% | 2910 fps | 100% |
| Lovex D073.6 | <<locked>> | 82% | 54,882 psi | 88% | 2858 fps | 100% |
| Lovex S060 | <<locked>> | 82% | 53,795 psi | 86% | 2808 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 55,332 psi | 89% | 2861 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 54,824 psi | 88% | 2877 fps | 99.4% |
| Lovex S070 | <<locked>> | 94% | 56,246 psi | 90% | 2920 fps | 99% |
| Lovex S071ᴾ | <<locked>> | 100% | 41,452 psi | 66% | 2687 fps | 96.9% |
| Norma 201 | <<locked>> | 82% | 53,490 psi | 86% | 2825 fps | 100% |
| Norma 202 | <<locked>> | 82% | 54,041 psi | 87% | 2825 fps | 100% |
| Norma 203B | <<locked>> | 86% | 56,057 psi | 90% | 2920 fps | 100% |
| Norma 204 | <<locked>> | 94% | 54,795 psi | 88% | 2933 fps | 97.1% |
| Norma MRPᴾ | <<locked>> | 100% | 52,649 psi | 84% | 3002 fps | 98.4% |
| Norma URP | <<locked>> | 94% | 54,766 psi | 88% | 2943 fps | 99.9% |
| Ramshot Big Game | <<locked>> | 84% | 53,214 psi | 85% | 2890 fps | 100% |
| Ramshot Hunter | <<locked>> | 94% | 53,548 psi | 86% | 2940 fps | 99.1% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,840 psi | 59% | 1841 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 54,346 psi | 87% | 2871 fps | 99% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 54,099 psi | 87% | 2946 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 53,882 psi | 86% | 2982 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 55,825 psi | 90% | 2979 fps | 99.9% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 54,389 psi | 87% | 3002 fps | 99.8% |
| Rottweil R 902 | <<locked>> | 84% | 54,041 psi | 87% | 2825 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 53,650 psi | 86% | 2867 fps | 100% |
| Rottweil R 904 | <<locked>> | 98% | 55,187 psi | 88% | 2907 fps | 96.1% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 55,303 psi | 89% | 2966 fps | 97.6% |
| Rottweil R 907 | <<locked>> | 90% | 53,461 psi | 86% | 2854 fps | 97.9% |
| Shooters World Long Rifle | <<locked>> | 92% | 54,824 psi | 88% | 2877 fps | 99.4% |
| Shooters World Match Rifle | <<locked>> | 82% | 54,882 psi | 88% | 2858 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 55,332 psi | 89% | 2861 fps | 100% |
| Shooters World SW4350 | <<locked>> | 94% | 56,246 psi | 90% | 2920 fps | 99% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 55,434 psi | 89% | 2930 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 55,869 psi | 90% | 2884 fps | 99.8% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 53,272 psi | 85% | 2854 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 54,418 psi | 87% | 2762 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 55,129 psi | 88% | 2762 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 54,766 psi | 88% | 2828 fps | 98.6% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 54,824 psi | 88% | 2959 fps | 97.5% |
| Somchem S335 | <<locked>> | 82% | 54,114 psi | 87% | 2759 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 55,579 psi | 89% | 2874 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 53,925 psi | 86% | 2867 fps | 100% |
| Somchem S365 | <<locked>> | 96% | 53,403 psi | 86% | 2943 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 56,057 psi | 90% | 2940 fps | 98.4% |
| Vihtavuori N133 | <<locked>> | 82% | 54,911 psi | 88% | 2746 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 54,157 psi | 87% | 2789 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 54,578 psi | 88% | 2805 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 55,013 psi | 88% | 2841 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 53,447 psi | 86% | 2884 fps | 99.8% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 48,240 psi | 77% | 2799 fps | 96.5% |
| Vihtavuori N540 | <<locked>> | 86% | 56,275 psi | 90% | 2848 fps | 100% |
| Vihtavuori N550 | <<locked>> | 94% | 55,956 psi | 90% | 2940 fps | 99.9% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 52,301 psi | 84% | 2940 fps | 100% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 52,953 psi | 85% | 2851 fps | 100% |
| Winchester 760 | <<locked>> | 92% | 54,708 psi | 88% | 2953 fps | 98.7% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 42,105 psi | 68% | 2900 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 53,098 psi | 85% | 2858 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 52,707 psi | 85% | 2877 fps | 96.8% |
Start Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 80% | 48,443 psi | 78% | 2707 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 46,630 psi | 75% | 2697 fps | 96.3% |
| Accurate 3100 | <<locked>> | 92% | 37,985 psi | 61% | 2615 fps | 95.8% |
| Accurate 4064 | <<locked>> | 80% | 45,876 psi | 74% | 2710 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 34,447 psi | 55% | 2549 fps | 96.4% |
| Accurate High Country | <<locked>> | 98% | 50,633 psi | 81% | 2969 fps | 95.5% |
| ADI AR 2206H | <<locked>> | 80% | 51,285 psi | 82% | 2828 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 43,671 psi | 70% | 2677 fps | 99.1% |
| ADI AR 2209 | <<locked>> | 94% | 46,905 psi | 75% | 2815 fps | 95.3% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 47,572 psi | 76% | 2881 fps | 99.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 43,859 psi | 70% | 2703 fps | 99.9% |
| Alliant Reloder-15 | <<locked>> | 80% | 46,818 psi | 75% | 2769 fps | 99.6% |
| Alliant Reloder-16 | <<locked>> | 80% | 34,127 psi | 55% | 2562 fps | 96.5% |
| Alliant Reloder-17 | <<locked>> | 80% | 38,319 psi | 61% | 2690 fps | 99.2% |
| Alliant Reloder-19 | <<locked>> | 94% | 46,354 psi | 74% | 2808 fps | 95.4% |
| Alliant Reloder-22 | <<locked>> | 98% | 46,572 psi | 75% | 2858 fps | 95.6% |
| Alliant Reloder-23 | <<locked>> | 84% | 28,210 psi | 45% | 2418 fps | 95.5% |
| Alliant Reloder-25 | <<locked>> | 96% | 36,114 psi | 58% | 2648 fps | 95.6% |
| Alliant Reloder-26 | <<locked>> | 88% | 34,679 psi | 56% | 2657 fps | 96% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 51,126 psi | 82% | 2844 fps | 99.7% |
| Bofors RP3 | <<locked>> | 80% | 44,092 psi | 71% | 2713 fps | 99.9% |
| Bofors RP5 | <<locked>> | 98% | 46,572 psi | 75% | 2858 fps | 95.6% |
| Bofors RP7 | <<locked>> | 82% | 41,597 psi | 67% | 2631 fps | 95.1% |
| Hodgdon H380 | <<locked>> | 80% | 44,541 psi | 71% | 2720 fps | 98.6% |
| Hodgdon H414 | <<locked>> | 82% | 39,175 psi | 63% | 2657 fps | 95% |
| Hodgdon H4350 | <<locked>> | 84% | 45,063 psi | 72% | 2740 fps | 95.4% |
| Hodgdon H4895 | <<locked>> | 80% | 51,822 psi | 83% | 2838 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 31,560 psi | 51% | 2461 fps | 97.3% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 48,472 psi | 78% | 2818 fps | 100% |
| Hodgdon Superformance | <<locked>> | 84% | 41,133 psi | 66% | 2730 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,934 psi | 43% | 1604 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 49,734 psi | 80% | 2789 fps | 100% |
| IMR 3031 | <<locked>> | 80% | 52,257 psi | 84% | 2822 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 45,919 psi | 74% | 2713 fps | 99.5% |
| IMR 4166 Enduron | <<locked>> | 80% | 48,196 psi | 77% | 2740 fps | 97.5% |
| IMR 4350 | <<locked>> | 86% | 42,163 psi | 68% | 2664 fps | 95.3% |
| IMR 4451 Enduron | <<locked>> | 80% | 40,480 psi | 65% | 2608 fps | 95.3% |
| IMR 4831 | <<locked>> | 80% | 33,388 psi | 54% | 2507 fps | 96.1% |
| IMR 4895 | <<locked>> | 80% | 48,022 psi | 77% | 2799 fps | 99.9% |
| Lovex D073.6 | <<locked>> | 80% | 51,474 psi | 83% | 2805 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 50,575 psi | 81% | 2756 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 46,064 psi | 74% | 2713 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 37,956 psi | 61% | 2559 fps | 96.1% |
| Lovex S070 | <<locked>> | 82% | 38,493 psi | 62% | 2589 fps | 95% |
| Lovex S071 | <<locked>> | 96% | 36,405 psi | 58% | 2579 fps | 95.2% |
| Norma 201 | <<locked>> | 80% | 50,256 psi | 81% | 2776 fps | 100% |
| Norma 202 | <<locked>> | 80% | 50,763 psi | 81% | 2776 fps | 100% |
| Norma 203B | <<locked>> | 80% | 46,195 psi | 74% | 2756 fps | 99.8% |
| Norma 204 | <<locked>> | 90% | 47,703 psi | 76% | 2812 fps | 95.5% |
| Norma MRP | <<locked>> | 92% | 40,016 psi | 64% | 2749 fps | 95.1% |
| Norma URP | <<locked>> | 80% | 34,505 psi | 55% | 2549 fps | 96.3% |
| Ramshot Big Game | <<locked>> | 80% | 46,296 psi | 74% | 2776 fps | 99.7% |
| Ramshot Hunter | <<locked>> | 84% | 38,261 psi | 61% | 2648 fps | 95.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,441 psi | 44% | 1644 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 44,585 psi | 71% | 2700 fps | 97.3% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 50,415 psi | 81% | 2887 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 40,756 psi | 65% | 2749 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 34,287 psi | 55% | 2566 fps | 96% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 36,071 psi | 58% | 2628 fps | 96% |
| Rottweil R 902 | <<locked>> | 80% | 47,863 psi | 77% | 2726 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 41,379 psi | 66% | 2657 fps | 99.6% |
| Rottweil R 904 | <<locked>> | 96% | 51,764 psi | 83% | 2848 fps | 95.4% |
| Rottweil R 905 | <<locked>> | 94% | 45,353 psi | 73% | 2789 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 82% | 41,597 psi | 67% | 2631 fps | 95.1% |
| Shooters World Long Rifle | <<locked>> | 80% | 37,956 psi | 61% | 2559 fps | 96.1% |
| Shooters World Match Rifle | <<locked>> | 80% | 51,474 psi | 83% | 2805 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 46,064 psi | 74% | 2713 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 38,493 psi | 62% | 2589 fps | 95% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 42,467 psi | 68% | 2710 fps | 99.3% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 52,257 psi | 84% | 2828 fps | 99.5% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 49,864 psi | 80% | 2799 fps | 99.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 51,271 psi | 82% | 2713 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 43,163 psi | 69% | 2582 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 39,668 psi | 64% | 2556 fps | 95.3% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 44,933 psi | 72% | 2785 fps | 95.2% |
| Somchem S335 | <<locked>> | 80% | 50,894 psi | 82% | 2713 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 52,011 psi | 83% | 2818 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 41,858 psi | 67% | 2657 fps | 99.5% |
| Somchem S365 | <<locked>> | 80% | 31,038 psi | 50% | 2503 fps | 98.4% |
| Somchem S385 | <<locked>> | 92% | 43,178 psi | 69% | 2717 fps | 95.6% |
| Vihtavuori N133 | <<locked>> | 80% | 51,764 psi | 83% | 2703 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 48,008 psi | 77% | 2700 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 48,138 psi | 77% | 2707 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 39,900 psi | 64% | 2589 fps | 99.8% |
| Vihtavuori N160 | <<locked>> | 80% | 35,853 psi | 57% | 2549 fps | 96.7% |
| Vihtavuori N165 | <<locked>> | 98% | 45,194 psi | 72% | 2743 fps | 95.7% |
| Vihtavuori N540 | <<locked>> | 80% | 46,543 psi | 75% | 2700 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 35,505 psi | 57% | 2552 fps | 96.4% |
| Vihtavuori N555 | <<locked>> | 84% | 30,821 psi | 49% | 2497 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 35,360 psi | 57% | 2526 fps | 98.7% |
| Winchester 760 | <<locked>> | 82% | 39,175 psi | 63% | 2657 fps | 95% |
| Winchester StaBALL HD | <<locked>> | 88% | 28,413 psi | 46% | 2507 fps | 96.4% |
| Winchester StaBALL Match | <<locked>> | 80% | 49,661 psi | 80% | 2805 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 45,847 psi | 74% | 2759 fps | 95.1% |
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 109 powders for .300 H&H Mag. loaded with the .308 | 168gr | Sierra MatchKing. Alliant Reloder-26 delivers the highest muzzle velocity at 3,054 fps; across all powders the maximum-charge window runs from 1,798 fps to 3,054 fps. Accurate 3100 gives the best case fill at 100 %, and 109 of the 109 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (430 MPa), the top charges use 58–90 %, leaving at least 10 % headroom. The 168.0 gr projectile in 0.308" calls for a 1:13.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate High Country, Accurate MAGPRO 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. As outliers, Accurate MAGPRO, ADI AR 2213, Hodgdon H1000 burn incompletely and react more sensitively to barrel length and temperature. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.