Load Specifications
Load data in caliber 37XC with .375 | 300gr | Impala RNFP bullet and 92 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Accurate MAGPRO, Alliant Reloder-26 and Vihtavuori N560.
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: 30"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2700 | <<locked>> | 82% | 61,554 psi | 88% | 2805 fps | 100% |
| Accurate 3100 | <<locked>> | 98% | 62,830 psi | 90% | 2881 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 60,568 psi | 87% | 2864 fps | 100% |
| Accurate MAGPRO | <<locked>> | 96% | 60,626 psi | 87% | 2995 fps | 99.5% |
| ADI APS 450 | <<locked>> | 82% | 60,901 psi | 87% | 2156 fps | 100% |
| ADI AR 2208 | <<locked>> | 84% | 60,524 psi | 87% | 2805 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 60,046 psi | 86% | 2917 fps | 100% |
| ADI AR 2213 | <<locked>> | 98% | 61,757 psi | 89% | 2986 fps | 99.9% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 48,820 psi | 70% | 2782 fps | 99% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 43,932 psi | 63% | 2766 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 62,395 psi | 90% | 2828 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 62,439 psi | 90% | 2854 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 60,176 psi | 86% | 2907 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 61,946 psi | 89% | 2923 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 59,669 psi | 86% | 2910 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 98% | 61,714 psi | 89% | 2979 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 62,729 psi | 90% | 2927 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 54,578 psi | 78% | 2904 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 94% | 59,785 psi | 86% | 2989 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 59,422 psi | 85% | 2887 fps | 98.1% |
| Bofors RP15ᴾ | <<locked>> | 100% | 60,466 psi | 87% | 2963 fps | 100% |
| Bofors RP3 | <<locked>> | 82% | 60,495 psi | 87% | 2805 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 50,865 psi | 73% | 2864 fps | 99.5% |
| Bofors RP5 | <<locked>> | 98% | 61,714 psi | 89% | 2979 fps | 100% |
| Bofors RP7 | <<locked>> | 88% | 62,221 psi | 89% | 2854 fps | 100% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 53,621 psi | 77% | 2861 fps | 99.8% |
| Hodgdon H380 | <<locked>> | 82% | 60,017 psi | 86% | 2825 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 61,525 psi | 88% | 2913 fps | 100% |
| Hodgdon H4350 | <<locked>> | 86% | 60,220 psi | 87% | 2867 fps | 100% |
| Hodgdon H4831 | <<locked>> | 96% | 61,786 psi | 89% | 2920 fps | 99.6% |
| Hodgdon H4831 SC | <<locked>> | 96% | 60,597 psi | 87% | 2904 fps | 99.6% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 60,829 psi | 87% | 2822 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 53,519 psi | 77% | 2979 fps | 100% |
| Hodgdon Superformance | <<locked>> | 88% | 62,265 psi | 89% | 2959 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,362 psi | 54% | 1729 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 60,162 psi | 86% | 2785 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 62,308 psi | 90% | 2828 fps | 100% |
| IMR 4350 | <<locked>> | 90% | 59,785 psi | 86% | 2841 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 86% | 59,727 psi | 86% | 2825 fps | 100% |
| IMR 4831 | <<locked>> | 90% | 60,220 psi | 87% | 2844 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 62,482 psi | 90% | 2897 fps | 99.7% |
| IMR 7828 SSC | <<locked>> | 98% | 59,408 psi | 85% | 2966 fps | 99.9% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 39,769 psi | 57% | 2684 fps | 97.5% |
| Lovex S062 | <<locked>> | 82% | 61,046 psi | 88% | 2779 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 60,771 psi | 87% | 2822 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 62,584 psi | 90% | 2871 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 56,391 psi | 81% | 2802 fps | 100% |
| Norma 203B | <<locked>> | 82% | 61,772 psi | 89% | 2838 fps | 100% |
| Norma 204 | <<locked>> | 90% | 60,988 psi | 88% | 2904 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 39,842 psi | 57% | 2710 fps | 99.3% |
| Norma MRP | <<locked>> | 96% | 61,830 psi | 89% | 3005 fps | 100% |
| Norma URP | <<locked>> | 90% | 61,844 psi | 89% | 2887 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 62,859 psi | 90% | 2864 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 60,307 psi | 87% | 2982 fps | 100% |
| Ramshot Hunter | <<locked>> | 90% | 60,408 psi | 87% | 2900 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 58,682 psi | 84% | 2920 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,232 psi | 55% | 1768 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 59,451 psi | 85% | 2812 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 61,337 psi | 88% | 2907 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 60,089 psi | 86% | 2887 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 61,786 psi | 89% | 2966 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 53,998 psi | 78% | 2976 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 49,298 psi | 71% | 2877 fps | 98.5% |
| Rottweil R 902 | <<locked>> | 82% | 62,932 psi | 90% | 2782 fps | 100% |
| Rottweil R 903 | <<locked>> | 84% | 60,669 psi | 87% | 2802 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 61,525 psi | 88% | 2884 fps | 99.8% |
| Rottweil R 905 | <<locked>> | 94% | 59,364 psi | 85% | 2900 fps | 100% |
| Rottweil R 907 | <<locked>> | 88% | 62,221 psi | 89% | 2854 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 88% | 60,771 psi | 87% | 2822 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 61,046 psi | 88% | 2779 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 62,584 psi | 90% | 2871 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 61,438 psi | 88% | 2854 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 59,669 psi | 86% | 2657 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 60,292 psi | 87% | 2779 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 62,772 psi | 90% | 2946 fps | 100% |
| Somchem S355 | <<locked>> | 84% | 59,915 psi | 86% | 2792 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 59,553 psi | 86% | 2828 fps | 99.4% |
| Somchem S365 | <<locked>> | 92% | 62,453 psi | 90% | 2884 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 60,176 psi | 86% | 2871 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 60,988 psi | 88% | 2759 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 60,031 psi | 86% | 2828 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 59,263 psi | 85% | 2844 fps | 100% |
| Vihtavuori N540 | <<locked>> | 82% | 61,380 psi | 88% | 2753 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 62,990 psi | 90% | 2887 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 61,975 psi | 89% | 2913 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 61,511 psi | 88% | 3005 fps | 99.8% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 57,551 psi | 83% | 2933 fps | 99.7% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 50,415 psi | 72% | 2881 fps | 98.2% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 59,364 psi | 85% | 2785 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 61,685 psi | 89% | 2917 fps | 100% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 60,437 psi | 87% | 3028 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 59,828 psi | 86% | 2864 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 30"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2700 | <<locked>> | 80% | 57,769 psi | 83% | 2756 fps | 100% |
| Accurate 3100 | <<locked>> | 80% | 35,868 psi | 52% | 2457 fps | 99.1% |
| Accurate 4350 | <<locked>> | 80% | 46,978 psi | 67% | 2674 fps | 100% |
| Accurate MAGPRO | 94.4 gr | 82% | 38,159 psi | 55% | 2608 fps | 95.3% |
| ADI APS 450 | <<locked>> | 80% | 58,943 psi | 85% | 2129 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 53,882 psi | 77% | 2717 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 38,928 psi | 56% | 2562 fps | 97.7% |
| ADI AR 2213 | <<locked>> | 80% | 35,012 psi | 50% | 2500 fps | 95.1% |
| ADI AR 2217 | <<locked>> | 90% | 35,984 psi | 52% | 2520 fps | 95.7% |
| ADI AR 2225 | <<locked>> | 84% | 27,615 psi | 40% | 2349 fps | 95.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 55,376 psi | 80% | 2740 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 58,755 psi | 84% | 2808 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 44,251 psi | 64% | 2674 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 50,734 psi | 73% | 2779 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 38,885 psi | 56% | 2559 fps | 97.8% |
| Alliant Reloder-22 | <<locked>> | 80% | 35,114 psi | 50% | 2520 fps | 96.9% |
| Alliant Reloder-23 | <<locked>> | 80% | 33,982 psi | 49% | 2484 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 29,950 psi | 43% | 2415 fps | 98.3% |
| Alliant Reloder-26 | 93.1 gr | 80% | 36,767 psi | 53% | 2621 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 47,050 psi | 68% | 2680 fps | 95.5% |
| Bofors RP15 | <<locked>> | 80% | 32,895 psi | 47% | 2464 fps | 96% |
| Bofors RP3 | <<locked>> | 80% | 56,855 psi | 82% | 2759 fps | 100% |
| Bofors RP30 | <<locked>> | 86% | 32,938 psi | 47% | 2500 fps | 95.3% |
| Bofors RP5 | <<locked>> | 80% | 35,114 psi | 50% | 2520 fps | 96.9% |
| Bofors RP7 | <<locked>> | 80% | 49,139 psi | 71% | 2664 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 86% | 34,476 psi | 50% | 2487 fps | 95.8% |
| Hodgdon H380 | <<locked>> | 80% | 56,405 psi | 81% | 2779 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 47,906 psi | 69% | 2717 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 80% | 50,285 psi | 72% | 2720 fps | 99.6% |
| Hodgdon H4831 | <<locked>> | 80% | 37,072 psi | 53% | 2500 fps | 95.2% |
| Hodgdon H4831 SC | <<locked>> | 80% | 36,564 psi | 53% | 2490 fps | 95% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 42,134 psi | 61% | 2562 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 82% | 31,038 psi | 45% | 2484 fps | 95.8% |
| Hodgdon Superformance | <<locked>> | 80% | 47,123 psi | 68% | 2743 fps | 99.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,094 psi | 40% | 1545 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 56,739 psi | 82% | 2743 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 58,610 psi | 84% | 2782 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 44,527 psi | 64% | 2605 fps | 99.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 50,111 psi | 72% | 2684 fps | 99.9% |
| IMR 4831 | <<locked>> | 80% | 44,512 psi | 64% | 2621 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 38,885 psi | 56% | 2503 fps | 96% |
| IMR 7828 SSC | <<locked>> | 82% | 35,926 psi | 52% | 2536 fps | 95.6% |
| IMR 8133 Enduron | <<locked>> | 94% | 33,446 psi | 48% | 2530 fps | 95.2% |
| Lovex S062 | <<locked>> | 80% | 57,580 psi | 83% | 2736 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 48,370 psi | 69% | 2644 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 46,702 psi | 67% | 2641 fps | 99.9% |
| Lovex S071 | <<locked>> | 80% | 31,401 psi | 45% | 2356 fps | 98% |
| Norma 203B | <<locked>> | 80% | 58,131 psi | 84% | 2792 fps | 100% |
| Norma 204 | <<locked>> | 80% | 44,440 psi | 64% | 2648 fps | 98.7% |
| Norma 217 | <<locked>> | 88% | 28,065 psi | 40% | 2402 fps | 95.1% |
| Norma MRP | <<locked>> | 80% | 36,535 psi | 52% | 2585 fps | 98.6% |
| Norma URP | <<locked>> | 80% | 45,629 psi | 66% | 2657 fps | 100% |
| Ramshot Big Game | <<locked>> | 80% | 58,987 psi | 85% | 2818 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 35,476 psi | 51% | 2539 fps | 95.8% |
| Ramshot Hunter | <<locked>> | 80% | 44,338 psi | 64% | 2661 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 80% | 29,979 psi | 43% | 2382 fps | 95.7% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,819 psi | 41% | 1585 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 55,825 psi | 80% | 2766 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 53,606 psi | 77% | 2812 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 46,456 psi | 67% | 2694 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 44,251 psi | 64% | 2710 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 28,326 psi | 41% | 2405 fps | 95.6% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 37,623 psi | 54% | 2644 fps | 95.3% |
| Rottweil R 902 | <<locked>> | 80% | 59,408 psi | 85% | 2740 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 53,722 psi | 77% | 2713 fps | 100% |
| Rottweil R 904 | <<locked>> | 80% | 40,263 psi | 58% | 2536 fps | 97% |
| Rottweil R 905 | <<locked>> | 80% | 38,450 psi | 55% | 2549 fps | 97.8% |
| Rottweil R 907 | <<locked>> | 80% | 49,139 psi | 71% | 2664 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 48,370 psi | 69% | 2644 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 57,580 psi | 83% | 2736 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 46,702 psi | 67% | 2641 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 54,360 psi | 78% | 2766 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 53,098 psi | 76% | 2579 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 47,224 psi | 68% | 2592 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 38,101 psi | 55% | 2543 fps | 97.7% |
| Somchem S355 | <<locked>> | 80% | 53,345 psi | 77% | 2707 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 41,031 psi | 59% | 2526 fps | 96.4% |
| Somchem S365 | <<locked>> | 80% | 42,743 psi | 61% | 2618 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 39,262 psi | 56% | 2533 fps | 98.6% |
| Vihtavuori N150 | <<locked>> | 80% | 50,995 psi | 73% | 2631 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 46,862 psi | 67% | 2644 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 34,026 psi | 49% | 2415 fps | 97% |
| Vihtavuori N540 | <<locked>> | 80% | 57,870 psi | 83% | 2710 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 46,427 psi | 67% | 2654 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 38,145 psi | 55% | 2552 fps | 100% |
| Vihtavuori N560 | 90.4 gr | 80% | 36,695 psi | 53% | 2569 fps | 95.5% |
| Vihtavuori N565 | <<locked>> | 84% | 34,722 psi | 50% | 2516 fps | 95.1% |
| Vihtavuori N568 | <<locked>> | 92% | 39,015 psi | 56% | 2657 fps | 95.1% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 45,585 psi | 65% | 2602 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 48,037 psi | 69% | 2720 fps | 99.9% |
| Winchester StaBALL HD | <<locked>> | 80% | 30,545 psi | 44% | 2526 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 35,708 psi | 51% | 2461 fps | 96.9% |
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 98 powders for 37XC loaded with the .375 | 300gr | Impala RNFP. Winchester StaBALL HD delivers the highest muzzle velocity at 3,028 fps; across all powders the maximum-charge window runs from 1,729 fps to 3,028 fps. ADI AR 2217 gives the best case fill at 100 %, and 98 of the 98 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (480 MPa), the top charges use 54–90 %, leaving at least 10 % headroom. The 300.0 gr projectile in 0.375" calls for a 1:16.5 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2218, ADI AR 2225 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. Accurate MAGPRO, Alliant Reloder-26, Vihtavuori N560 rank at the top here: for 37XC with the .375 | 300gr | Impala RNFP they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, ADI AR 2218, Alliant Reloder-50, IMR 7977 Enduron 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.