Load Specifications
Load data in caliber 37XC with .375 | 305gr | Hammer Stone Hammer bullet and 96 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Vihtavuori N560, Accurate MAGPRO and Norma MRP.
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.
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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% | 60,292 psi | 87% | 2792 fps | 100% |
| Accurate 3100 | <<locked>> | 98% | 60,959 psi | 88% | 2864 fps | 100% |
| Accurate 4064 | <<locked>> | 82% | 60,379 psi | 87% | 2753 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 62,627 psi | 90% | 2890 fps | 100% |
| Accurate MAGPRO | <<locked>> | 96% | 59,480 psi | 85% | 2986 fps | 99.6% |
| ADI APS 450 | <<locked>> | 84% | 62,961 psi | 90% | 2182 fps | 100% |
| ADI AR 2208 | <<locked>> | 84% | 59,538 psi | 86% | 2795 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 59,292 psi | 85% | 2910 fps | 100% |
| ADI AR 2213 | <<locked>> | 98% | 60,727 psi | 87% | 2976 fps | 100% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 47,587 psi | 68% | 2769 fps | 99.2% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 42,308 psi | 61% | 2743 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 60,974 psi | 88% | 2812 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 61,032 psi | 88% | 2841 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 59,321 psi | 85% | 2894 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 60,800 psi | 87% | 2910 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 62,337 psi | 90% | 2946 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 98% | 60,481 psi | 87% | 2966 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 61,685 psi | 89% | 2913 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 53,359 psi | 77% | 2887 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 96% | 62,946 psi | 90% | 3025 fps | 100% |
| Baschieri & Pellagri 109ᴾ | <<locked>> | 100% | 62,366 psi | 90% | 2933 fps | 98.8% |
| Bofors RP15ᴾ | <<locked>> | 100% | 59,379 psi | 85% | 2953 fps | 100% |
| Bofors RP3 | <<locked>> | 84% | 62,308 psi | 90% | 2831 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 49,371 psi | 71% | 2844 fps | 99.6% |
| Bofors RP5 | <<locked>> | 98% | 60,481 psi | 87% | 2966 fps | 100% |
| Bofors RP7 | <<locked>> | 88% | 61,017 psi | 88% | 2844 fps | 100% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 52,475 psi | 75% | 2851 fps | 99.9% |
| Hodgdon H380 | <<locked>> | 84% | 62,482 psi | 90% | 2861 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 60,249 psi | 87% | 2900 fps | 100% |
| Hodgdon H4350 | <<locked>> | 86% | 59,248 psi | 85% | 2861 fps | 100% |
| Hodgdon H4831 | <<locked>> | 96% | 60,829 psi | 87% | 2910 fps | 99.7% |
| Hodgdon H4831 SC | <<locked>> | 96% | 59,553 psi | 86% | 2894 fps | 99.7% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 59,567 psi | 86% | 2808 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 52,301 psi | 75% | 2966 fps | 100% |
| Hodgdon Superformance | <<locked>> | 88% | 61,279 psi | 88% | 2949 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,086 psi | 53% | 1726 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 62,700 psi | 90% | 2818 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 61,264 psi | 88% | 2822 fps | 100% |
| IMR 4350 | <<locked>> | 92% | 62,642 psi | 90% | 2881 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 88% | 62,453 psi | 90% | 2861 fps | 100% |
| IMR 4831 | <<locked>> | 92% | 62,482 psi | 90% | 2877 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 62,627 psi | 90% | 2861 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 61,670 psi | 89% | 2890 fps | 99.8% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 62,613 psi | 90% | 3009 fps | 100% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 37,913 psi | 54% | 2651 fps | 97.4% |
| Lovex S062 | <<locked>> | 82% | 59,364 psi | 85% | 2762 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 59,234 psi | 85% | 2808 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 61,119 psi | 88% | 2858 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 54,157 psi | 78% | 2779 fps | 100% |
| Norma 203B | <<locked>> | 82% | 60,350 psi | 87% | 2825 fps | 100% |
| Norma 204 | <<locked>> | 90% | 59,988 psi | 86% | 2894 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 37,869 psi | 54% | 2677 fps | 99.3% |
| Norma MRP | <<locked>> | 96% | 60,684 psi | 87% | 2989 fps | 100% |
| Norma URP | <<locked>> | 90% | 60,524 psi | 87% | 2874 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 61,612 psi | 89% | 2851 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 59,335 psi | 85% | 2972 fps | 100% |
| Ramshot Hunter | <<locked>> | 90% | 59,263 psi | 85% | 2887 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 57,522 psi | 83% | 2904 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,869 psi | 54% | 1768 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 62,018 psi | 89% | 2851 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 60,437 psi | 87% | 2894 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 62,627 psi | 90% | 2917 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 60,916 psi | 88% | 2953 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 52,721 psi | 76% | 2959 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 47,645 psi | 68% | 2858 fps | 98.5% |
| Rottweil R 902 | <<locked>> | 82% | 61,351 psi | 88% | 2769 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 62,555 psi | 90% | 2828 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 60,365 psi | 87% | 2874 fps | 99.9% |
| Rottweil R 905 | <<locked>> | 96% | 62,004 psi | 89% | 2936 fps | 100% |
| Rottweil R 907 | <<locked>> | 88% | 61,017 psi | 88% | 2844 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 88% | 59,234 psi | 85% | 2808 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 59,364 psi | 85% | 2762 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 61,119 psi | 88% | 2858 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 60,321 psi | 87% | 2844 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 62,207 psi | 89% | 2687 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 62,671 psi | 90% | 2815 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 61,525 psi | 88% | 2933 fps | 100% |
| Somchem S355 | <<locked>> | 86% | 62,004 psi | 89% | 2825 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 62,323 psi | 90% | 2867 fps | 99.8% |
| Somchem S365 | <<locked>> | 92% | 61,090 psi | 88% | 2871 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 62,497 psi | 90% | 2904 fps | 100% |
| Vihtavuori N135 | <<locked>> | 82% | 62,120 psi | 89% | 2713 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 61,946 psi | 89% | 2733 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 59,553 psi | 86% | 2746 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 62,627 psi | 90% | 2861 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 62,076 psi | 89% | 2881 fps | 100% |
| Vihtavuori N540 | <<locked>> | 82% | 60,075 psi | 86% | 2740 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 61,685 psi | 89% | 2874 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 60,321 psi | 87% | 2897 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 60,495 psi | 87% | 2995 fps | 99.9% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 56,043 psi | 81% | 2917 fps | 99.7% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 48,936 psi | 70% | 2864 fps | 98.3% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 62,410 psi | 90% | 2818 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 60,408 psi | 87% | 2904 fps | 100% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 59,451 psi | 85% | 3009 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 62,845 psi | 90% | 2907 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% | 56,507 psi | 81% | 2746 fps | 100% |
| Accurate 3100 | <<locked>> | 80% | 33,257 psi | 48% | 2418 fps | 98.8% |
| Accurate 4064 | <<locked>> | 80% | 56,869 psi | 82% | 2710 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 44,657 psi | 64% | 2648 fps | 100% |
| Accurate MAGPRO | 96.6 gr | 82% | 36,216 psi | 52% | 2575 fps | 95.1% |
| ADI APS 450 | <<locked>> | 80% | 58,929 psi | 85% | 2126 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 52,707 psi | 76% | 2703 fps | 100% |
| ADI AR 2209 | <<locked>> | 80% | 37,289 psi | 54% | 2539 fps | 97.7% |
| ADI AR 2213 | <<locked>> | 82% | 35,563 psi | 51% | 2530 fps | 95.8% |
| ADI AR 2217 | <<locked>> | 90% | 34,258 psi | 49% | 2493 fps | 95.6% |
| ADI AR 2225 | <<locked>> | 86% | 27,137 psi | 39% | 2356 fps | 95.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 53,940 psi | 77% | 2723 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 57,363 psi | 82% | 2792 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 42,830 psi | 62% | 2654 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 49,269 psi | 71% | 2759 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 37,289 psi | 54% | 2536 fps | 97.7% |
| Alliant Reloder-22 | <<locked>> | 80% | 33,170 psi | 48% | 2487 fps | 96.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 31,937 psi | 46% | 2448 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 27,862 psi | 40% | 2369 fps | 97.9% |
| Alliant Reloder-26 | <<locked>> | 80% | 34,722 psi | 50% | 2585 fps | 99.9% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 45,861 psi | 66% | 2671 fps | 95.7% |
| Bofors RP15 | <<locked>> | 80% | 30,864 psi | 44% | 2425 fps | 95.5% |
| Bofors RP3 | <<locked>> | 80% | 54,839 psi | 79% | 2740 fps | 100% |
| Bofors RP30 | <<locked>> | 88% | 32,996 psi | 47% | 2516 fps | 95.9% |
| Bofors RP5 | <<locked>> | 80% | 33,170 psi | 48% | 2487 fps | 96.7% |
| Bofors RP7 | <<locked>> | 80% | 47,601 psi | 68% | 2648 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 86% | 32,735 psi | 47% | 2457 fps | 95.6% |
| Hodgdon H380 | <<locked>> | 80% | 54,766 psi | 79% | 2762 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 46,282 psi | 66% | 2697 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 80% | 48,950 psi | 70% | 2707 fps | 99.7% |
| Hodgdon H4831 | <<locked>> | 80% | 35,418 psi | 51% | 2477 fps | 95.1% |
| Hodgdon H4831 SC | <<locked>> | 82% | 37,289 psi | 54% | 2516 fps | 95.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 40,422 psi | 58% | 2539 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 82% | 29,022 psi | 42% | 2441 fps | 95.2% |
| Hodgdon Superformance | <<locked>> | 80% | 45,585 psi | 65% | 2723 fps | 99.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,746 psi | 40% | 1542 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 55,463 psi | 80% | 2730 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 57,609 psi | 83% | 2772 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 43,004 psi | 62% | 2589 fps | 99.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 48,820 psi | 70% | 2671 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 42,540 psi | 61% | 2595 fps | 100% |
| IMR 4895 | <<locked>> | 80% | 58,842 psi | 85% | 2818 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 37,347 psi | 54% | 2480 fps | 95.9% |
| IMR 7828 SSC | <<locked>> | 82% | 34,156 psi | 49% | 2507 fps | 95.4% |
| IMR 8133 Enduron | <<locked>> | 96% | 33,286 psi | 48% | 2543 fps | 95.7% |
| Lovex S062 | <<locked>> | 80% | 55,898 psi | 80% | 2720 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 46,514 psi | 67% | 2621 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 44,730 psi | 64% | 2618 fps | 99.9% |
| Lovex S071 | <<locked>> | 80% | 28,718 psi | 41% | 2306 fps | 97.5% |
| Norma 203B | <<locked>> | 80% | 56,681 psi | 81% | 2779 fps | 100% |
| Norma 204 | <<locked>> | 80% | 42,902 psi | 62% | 2628 fps | 98.8% |
| Norma 217 | <<locked>> | 90% | 27,427 psi | 39% | 2402 fps | 95.4% |
| Norma MRP | 92.6 gr | 80% | 34,621 psi | 50% | 2552 fps | 98.5% |
| Norma URP | <<locked>> | 80% | 43,830 psi | 63% | 2635 fps | 100% |
| Ramshot Big Game | <<locked>> | 80% | 57,740 psi | 83% | 2805 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 33,620 psi | 48% | 2510 fps | 95.6% |
| Ramshot Hunter | <<locked>> | 80% | 42,685 psi | 61% | 2638 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 80% | 27,847 psi | 40% | 2339 fps | 95.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,398 psi | 41% | 1581 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 54,549 psi | 78% | 2753 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 52,330 psi | 75% | 2792 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 44,483 psi | 64% | 2667 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 42,772 psi | 61% | 2690 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 82% | 27,949 psi | 40% | 2411 fps | 96% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 35,578 psi | 51% | 2612 fps | 95.1% |
| Rottweil R 902 | <<locked>> | 80% | 57,638 psi | 83% | 2726 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 51,634 psi | 74% | 2690 fps | 100% |
| Rottweil R 904 | <<locked>> | 80% | 38,653 psi | 56% | 2516 fps | 96.9% |
| Rottweil R 905 | <<locked>> | 80% | 36,579 psi | 53% | 2520 fps | 97.7% |
| Rottweil R 907 | <<locked>> | 80% | 47,601 psi | 68% | 2648 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 46,514 psi | 67% | 2621 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 55,898 psi | 80% | 2720 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 44,730 psi | 64% | 2618 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 52,939 psi | 76% | 2749 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 51,851 psi | 74% | 2566 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 45,469 psi | 65% | 2575 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 36,245 psi | 52% | 2516 fps | 97.6% |
| Somchem S355 | <<locked>> | 80% | 51,547 psi | 74% | 2687 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 39,320 psi | 56% | 2503 fps | 96.3% |
| Somchem S365 | <<locked>> | 80% | 40,770 psi | 59% | 2592 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 37,217 psi | 53% | 2503 fps | 98.5% |
| Vihtavuori N135 | <<locked>> | 80% | 58,450 psi | 84% | 2674 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 58,247 psi | 84% | 2690 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 49,240 psi | 71% | 2612 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 45,281 psi | 65% | 2625 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 32,169 psi | 46% | 2385 fps | 96.7% |
| Vihtavuori N540 | <<locked>> | 80% | 56,376 psi | 81% | 2694 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 44,628 psi | 64% | 2631 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 35,868 psi | 52% | 2516 fps | 100% |
| Vihtavuori N560 | 92.6 gr | 80% | 34,940 psi | 50% | 2539 fps | 95.3% |
| Vihtavuori N565 | <<locked>> | 86% | 34,780 psi | 50% | 2533 fps | 95.6% |
| Vihtavuori N568 | <<locked>> | 92% | 37,086 psi | 53% | 2628 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 44,222 psi | 64% | 2585 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 46,398 psi | 67% | 2697 fps | 99.9% |
| Winchester StaBALL HD | <<locked>> | 80% | 28,326 psi | 41% | 2477 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 33,823 psi | 49% | 2431 fps | 96.7% |
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 102 powders for 37XC loaded with the .375 | 305gr | Hammer Stone Hammer. Alliant Reloder-26 delivers the highest muzzle velocity at 3,025 fps; across all powders the maximum-charge window runs from 1,726 fps to 3,025 fps. ADI AR 2217 gives the best case fill at 100 %, and 102 of the 102 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (480 MPa), the top charges use 51–90 %, leaving at least 10 % headroom. The 305.0 gr projectile in 0.375" calls for a 1:17.0 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. Vihtavuori N560, Accurate MAGPRO, Norma MRP rank at the top here: for 37XC with the .375 | 305gr | Hammer Stone Hammer 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.