Load Specifications
Load data in caliber .375 Blaser Mag. with .375 | 260gr | Nosler Partition bullet and 97 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.
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You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 82% | 52,098 psi | 86% | 2638 fps | 100% |
| Accurate 2495 | <<locked>> | 88% | 54,085 psi | 89% | 2707 fps | 100% |
| Accurate 2520 | <<locked>> | 82% | 52,112 psi | 86% | 2723 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 53,258 psi | 87% | 2707 fps | 97.1% |
| Accurate 3100ᴾ | <<locked>> | 100% | 40,988 psi | 67% | 2605 fps | 96.3% |
| Accurate 4064 | <<locked>> | 90% | 53,998 psi | 89% | 2753 fps | 100% |
| Accurate 4350 | <<locked>> | 98% | 53,577 psi | 88% | 2835 fps | 99.7% |
| ADI AR 2206H | <<locked>> | 86% | 54,462 psi | 89% | 2785 fps | 100% |
| ADI AR 2208 | <<locked>> | 90% | 52,127 psi | 86% | 2736 fps | 99.8% |
| ADI Benchmark 8208 | <<locked>> | 84% | 53,374 psi | 88% | 2736 fps | 100% |
| Alliant AR-Comp | <<locked>> | 84% | 54,273 psi | 89% | 2710 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 88% | 53,867 psi | 88% | 2900 fps | 99.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 90% | 52,025 psi | 85% | 2759 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 88% | 52,663 psi | 86% | 2779 fps | 99.9% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 54,897 psi | 90% | 2890 fps | 99.9% |
| Alliant Reloder-17 | <<locked>> | 94% | 52,402 psi | 86% | 2874 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 39,334 psi | 65% | 2641 fps | 99.1% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 43,801 psi | 72% | 2795 fps | 98.4% |
| Baschieri & Pellagri 107 | <<locked>> | 86% | 54,157 psi | 89% | 2799 fps | 99.8% |
| Bofors RP3 | <<locked>> | 90% | 52,504 psi | 86% | 2772 fps | 100% |
| Bofors RP7 | <<locked>> | 94% | 52,707 psi | 87% | 2740 fps | 97.2% |
| Hodgdon Benchmark | <<locked>> | 82% | 52,011 psi | 85% | 2674 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 84% | 52,750 psi | 87% | 2766 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 82% | 54,592 psi | 90% | 2861 fps | 99.9% |
| Hodgdon H380 | <<locked>> | 90% | 53,519 psi | 88% | 2785 fps | 99.4% |
| Hodgdon H414 | <<locked>> | 96% | 52,997 psi | 87% | 2835 fps | 98% |
| Hodgdon H4350 | <<locked>> | 94% | 53,751 psi | 88% | 2799 fps | 96.8% |
| Hodgdon H4895 | <<locked>> | 86% | 54,984 psi | 90% | 2795 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 51,126 psi | 84% | 2769 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 88% | 54,259 psi | 89% | 2828 fps | 100% |
| Hodgdon Superformance | <<locked>> | 96% | 53,519 psi | 88% | 2867 fps | 97.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,520 psi | 58% | 1690 fps | 100% |
| Hodgdon VARGET | <<locked>> | 86% | 52,881 psi | 87% | 2749 fps | 100% |
| IMR 3031 | <<locked>> | 86% | 54,940 psi | 90% | 2772 fps | 100% |
| IMR 4064 | <<locked>> | 90% | 54,940 psi | 90% | 2769 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 88% | 54,853 psi | 90% | 2749 fps | 98.1% |
| IMR 4350 | <<locked>> | 98% | 52,808 psi | 87% | 2766 fps | 97.3% |
| IMR 4451 Enduron | <<locked>> | 94% | 54,650 psi | 90% | 2776 fps | 98% |
| IMR 4831ᴾ | <<locked>> | 100% | 54,128 psi | 89% | 2828 fps | 99.8% |
| IMR 4895 | <<locked>> | 88% | 54,012 psi | 89% | 2808 fps | 100% |
| IMR 8208 XBR | <<locked>> | 84% | 53,374 psi | 88% | 2736 fps | 100% |
| Lovex D073.6 | <<locked>> | 86% | 54,128 psi | 89% | 2759 fps | 100% |
| Lovex S060 | <<locked>> | 86% | 53,969 psi | 89% | 2713 fps | 100% |
| Lovex S062 | <<locked>> | 90% | 54,810 psi | 90% | 2766 fps | 100% |
| Lovex S065 | <<locked>> | 96% | 53,969 psi | 89% | 2769 fps | 99% |
| Lovex S070 | <<locked>> | 98% | 54,882 psi | 90% | 2802 fps | 98.3% |
| Norma 201 | <<locked>> | 86% | 53,156 psi | 87% | 2730 fps | 100% |
| Norma 202 | <<locked>> | 86% | 53,780 psi | 88% | 2733 fps | 100% |
| Norma 203B | <<locked>> | 88% | 51,880 psi | 85% | 2766 fps | 99.9% |
| Norma 204 | <<locked>> | 98% | 53,287 psi | 87% | 2812 fps | 96.1% |
| Norma URP | <<locked>> | 98% | 52,779 psi | 87% | 2825 fps | 99.6% |
| Ramshot Big Game | <<locked>> | 88% | 52,054 psi | 85% | 2789 fps | 99.9% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 55,056 psi | 90% | 2874 fps | 99% |
| Ramshot TAC | <<locked>> | 84% | 53,548 psi | 88% | 2756 fps | 99.1% |
| Ramshot Wild Boar | <<locked>> | 84% | 53,214 psi | 87% | 2772 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 82% | 54,302 psi | 89% | 2740 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,042 psi | 59% | 1729 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 53,679 psi | 88% | 2766 fps | 98.5% |
| ReloadSwiss RS 52 | <<locked>> | 86% | 52,910 psi | 87% | 2841 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 92% | 52,315 psi | 86% | 2877 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 98% | 53,272 psi | 87% | 2861 fps | 99.6% |
| ReloadSwiss RS 70 | <<locked>> | 98% | 52,997 psi | 87% | 2887 fps | 99.4% |
| Rottweil R 901 | <<locked>> | 84% | 54,259 psi | 89% | 2713 fps | 100% |
| Rottweil R 902 | <<locked>> | 88% | 53,766 psi | 88% | 2730 fps | 100% |
| Rottweil R 903 | <<locked>> | 92% | 52,344 psi | 86% | 2766 fps | 100% |
| Rottweil R 907 | <<locked>> | 94% | 52,707 psi | 87% | 2740 fps | 97.2% |
| Shooters World Long Rifle | <<locked>> | 96% | 53,969 psi | 89% | 2769 fps | 99% |
| Shooters World Match Rifle | <<locked>> | 86% | 54,128 psi | 89% | 2759 fps | 100% |
| Shooters World Precision | <<locked>> | 90% | 54,810 psi | 90% | 2766 fps | 100% |
| Shooters World SW4350 | <<locked>> | 98% | 54,882 psi | 90% | 2802 fps | 98.3% |
| SNPE Vectan SP 11 | <<locked>> | 92% | 54,114 psi | 89% | 2825 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 84% | 51,938 psi | 85% | 2730 fps | 99.2% |
| SNPE Vectan SP 9 | <<locked>> | 86% | 52,852 psi | 87% | 2756 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 54,810 psi | 90% | 2671 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 54,911 psi | 90% | 2667 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 54,172 psi | 89% | 2720 fps | 98% |
| Somchem S321 | <<locked>> | 82% | 54,578 psi | 90% | 2769 fps | 100% |
| Somchem S335 | <<locked>> | 86% | 54,041 psi | 89% | 2667 fps | 100% |
| Somchem S341 | <<locked>> | 84% | 51,692 psi | 85% | 2726 fps | 99.9% |
| Somchem S355 | <<locked>> | 92% | 52,765 psi | 87% | 2762 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 50,546 psi | 83% | 2825 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 47,210 psi | 78% | 2710 fps | 96.1% |
| Vihtavuori N130 | <<locked>> | 82% | 54,491 psi | 89% | 2631 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 55,056 psi | 90% | 2654 fps | 100% |
| Vihtavuori N135 | <<locked>> | 88% | 53,388 psi | 88% | 2694 fps | 100% |
| Vihtavuori N140 | <<locked>> | 88% | 54,201 psi | 89% | 2710 fps | 100% |
| Vihtavuori N150 | <<locked>> | 94% | 54,215 psi | 89% | 2743 fps | 100% |
| Vihtavuori N160 | <<locked>> | 96% | 51,677 psi | 85% | 2769 fps | 99.4% |
| Vihtavuori N530 | <<locked>> | 84% | 53,795 psi | 88% | 2733 fps | 100% |
| Vihtavuori N540 | <<locked>> | 88% | 52,460 psi | 86% | 2710 fps | 100% |
| Vihtavuori N550 | <<locked>> | 98% | 54,288 psi | 89% | 2828 fps | 99.6% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 43,091 psi | 71% | 2713 fps | 99% |
| Winchester 6.5 StaBALL | <<locked>> | 96% | 51,938 psi | 85% | 2749 fps | 100% |
| Winchester 748 | <<locked>> | 84% | 53,766 psi | 88% | 2782 fps | 100% |
| Winchester 760 | <<locked>> | 96% | 53,171 psi | 87% | 2838 fps | 98% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 35,172 psi | 58% | 2644 fps | 99.1% |
| Winchester StaBALL Match | <<locked>> | 86% | 52,562 psi | 86% | 2762 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 80% | 48,950 psi | 80% | 2595 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 41,727 psi | 69% | 2526 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 48,646 psi | 80% | 2671 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 46,702 psi | 77% | 2602 fps | 95.7% |
| Accurate 3100 | <<locked>> | 98% | 38,218 psi | 63% | 2552 fps | 95.5% |
| Accurate 4064 | <<locked>> | 80% | 39,479 psi | 65% | 2523 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 33,054 psi | 54% | 2454 fps | 95.6% |
| ADI AR 2206H | <<locked>> | 80% | 45,121 psi | 74% | 2631 fps | 99.5% |
| ADI AR 2208 | <<locked>> | 80% | 38,348 psi | 63% | 2487 fps | 97.8% |
| ADI Benchmark 8208 | <<locked>> | 80% | 47,210 psi | 78% | 2638 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 47,630 psi | 78% | 2621 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 40,988 psi | 67% | 2667 fps | 98.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 37,985 psi | 62% | 2510 fps | 99% |
| Alliant Reloder-15 | <<locked>> | 80% | 40,843 psi | 67% | 2572 fps | 98.5% |
| Alliant Reloder-16 | <<locked>> | 84% | 33,518 psi | 55% | 2467 fps | 95.8% |
| Alliant Reloder-17 | 74.3 gr | 80% | 32,866 psi | 54% | 2480 fps | 97.4% |
| Alliant Reloder-23 | <<locked>> | 90% | 28,935 psi | 48% | 2375 fps | 95.4% |
| Alliant Reloder-26 | <<locked>> | 94% | 35,534 psi | 58% | 2608 fps | 95.8% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 44,338 psi | 73% | 2638 fps | 98.7% |
| Bofors RP3 | <<locked>> | 80% | 37,739 psi | 62% | 2516 fps | 99% |
| Bofors RP7 | <<locked>> | 88% | 43,758 psi | 72% | 2585 fps | 95.2% |
| Hodgdon Benchmark | <<locked>> | 80% | 48,849 psi | 80% | 2625 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 46,021 psi | 76% | 2661 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 80% | 50,923 psi | 84% | 2805 fps | 99.8% |
| Hodgdon H380 | <<locked>> | 80% | 38,450 psi | 63% | 2516 fps | 96.8% |
| Hodgdon H414 | <<locked>> | 88% | 40,654 psi | 67% | 2615 fps | 95.1% |
| Hodgdon H4350 | <<locked>> | 90% | 47,297 psi | 78% | 2690 fps | 95.4% |
| Hodgdon H4895 | <<locked>> | 80% | 45,542 psi | 75% | 2644 fps | 99.7% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 28,863 psi | 47% | 2320 fps | 95.7% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 41,452 psi | 68% | 2618 fps | 99.6% |
| Hodgdon Superformance | <<locked>> | 90% | 43,221 psi | 71% | 2684 fps | 95.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,542 psi | 44% | 1509 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 43,729 psi | 72% | 2598 fps | 99.5% |
| IMR 3031 | <<locked>> | 80% | 45,266 psi | 74% | 2635 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 40,277 psi | 66% | 2520 fps | 98.4% |
| IMR 4166 Enduron | <<locked>> | 80% | 42,786 psi | 70% | 2539 fps | 95.5% |
| IMR 4350 | <<locked>> | 92% | 43,961 psi | 72% | 2615 fps | 95.3% |
| IMR 4451 Enduron | <<locked>> | 86% | 42,801 psi | 70% | 2569 fps | 95.4% |
| IMR 4831 | <<locked>> | 84% | 32,097 psi | 53% | 2415 fps | 95.3% |
| IMR 4895 | <<locked>> | 80% | 41,829 psi | 69% | 2602 fps | 99.1% |
| IMR 8208 XBR | <<locked>> | 80% | 47,210 psi | 78% | 2638 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 44,251 psi | 73% | 2612 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 45,150 psi | 74% | 2569 fps | 99.5% |
| Lovex S062 | <<locked>> | 80% | 40,277 psi | 66% | 2526 fps | 99.5% |
| Lovex S065 | <<locked>> | 84% | 37,405 psi | 61% | 2467 fps | 95.5% |
| Lovex S070 | <<locked>> | 88% | 40,161 psi | 66% | 2546 fps | 95.1% |
| Norma 201 | <<locked>> | 80% | 44,295 psi | 73% | 2585 fps | 99.9% |
| Norma 202 | <<locked>> | 80% | 44,469 psi | 73% | 2589 fps | 100% |
| Norma 203B | <<locked>> | 80% | 40,205 psi | 66% | 2559 fps | 98.8% |
| Norma 204 | <<locked>> | 96% | 49,893 psi | 82% | 2756 fps | 95.3% |
| Norma URP | <<locked>> | 84% | 33,446 psi | 55% | 2457 fps | 95.6% |
| Ramshot Big Game | <<locked>> | 80% | 39,711 psi | 65% | 2572 fps | 98.6% |
| Ramshot Hunter | <<locked>> | 90% | 39,682 psi | 65% | 2602 fps | 95.7% |
| Ramshot TAC | <<locked>> | 80% | 46,992 psi | 77% | 2644 fps | 98.1% |
| Ramshot Wild Boar | <<locked>> | 80% | 46,557 psi | 76% | 2664 fps | 99.6% |
| Ramshot X-Terminator | <<locked>> | 80% | 50,894 psi | 84% | 2687 fps | 99.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,803 psi | 44% | 1545 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 38,841 psi | 64% | 2497 fps | 95.1% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 42,989 psi | 71% | 2674 fps | 98.9% |
| ReloadSwiss RS 60 | 74.3 gr | 80% | 34,983 psi | 57% | 2546 fps | 99.7% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 32,895 psi | 54% | 2470 fps | 95.1% |
| ReloadSwiss RS 70 | <<locked>> | 86% | 35,360 psi | 58% | 2530 fps | 95% |
| Rottweil R 901 | <<locked>> | 80% | 48,298 psi | 79% | 2625 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 42,148 psi | 69% | 2539 fps | 99.7% |
| Rottweil R 903 | <<locked>> | 80% | 35,433 psi | 58% | 2461 fps | 98.3% |
| Rottweil R 907 | <<locked>> | 88% | 43,758 psi | 72% | 2585 fps | 95.2% |
| Shooters World Long Rifle | <<locked>> | 84% | 37,405 psi | 61% | 2467 fps | 95.5% |
| Shooters World Match Rifle | <<locked>> | 80% | 44,251 psi | 73% | 2612 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 40,277 psi | 66% | 2526 fps | 99.5% |
| Shooters World SW4350 | <<locked>> | 88% | 40,161 psi | 66% | 2546 fps | 95.1% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 36,376 psi | 60% | 2510 fps | 97.9% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 45,353 psi | 74% | 2621 fps | 98.2% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 43,598 psi | 72% | 2602 fps | 99.3% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 45,455 psi | 75% | 2533 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 37,855 psi | 62% | 2405 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 41,756 psi | 69% | 2516 fps | 95.3% |
| Somchem S321 | <<locked>> | 80% | 51,082 psi | 84% | 2717 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 45,223 psi | 74% | 2539 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 45,150 psi | 74% | 2618 fps | 99.4% |
| Somchem S355 | <<locked>> | 80% | 36,376 psi | 60% | 2467 fps | 98.4% |
| Somchem S365 | <<locked>> | 80% | 26,353 psi | 43% | 2303 fps | 96.1% |
| Somchem S385 | <<locked>> | 98% | 44,179 psi | 73% | 2657 fps | 95.3% |
| Vihtavuori N130 | <<locked>> | 80% | 51,242 psi | 84% | 2589 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 45,788 psi | 75% | 2526 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 41,553 psi | 68% | 2520 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 42,090 psi | 69% | 2526 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 34,490 psi | 57% | 2402 fps | 99% |
| Vihtavuori N160 | <<locked>> | 82% | 32,808 psi | 54% | 2408 fps | 95.2% |
| Vihtavuori N530 | <<locked>> | 80% | 47,340 psi | 78% | 2635 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 40,567 psi | 67% | 2520 fps | 100% |
| Vihtavuori N550 | <<locked>> | 84% | 34,374 psi | 56% | 2457 fps | 95.6% |
| Vihtavuori N555 | <<locked>> | 90% | 31,038 psi | 51% | 2448 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 30,589 psi | 50% | 2333 fps | 96.6% |
| Winchester 748 | <<locked>> | 80% | 46,992 psi | 77% | 2680 fps | 100% |
| Winchester 760 | 80 gr | 88% | 40,799 psi | 67% | 2615 fps | 95.1% |
| Winchester StaBALL HD | <<locked>> | 94% | 29,022 psi | 48% | 2454 fps | 96% |
| Winchester StaBALL Match | <<locked>> | 80% | 43,018 psi | 71% | 2608 fps | 99.5% |
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 97 powders for .375 Blaser Mag. loaded with the .375 | 260gr | Nosler Partition. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 2,900 fps; across all powders the maximum-charge window runs from 1,690 fps to 2,900 fps. Accurate 3100 gives the best case fill at 100 %, and 97 of the 97 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (420 MPa), the top charges use 58–90 %, leaving at least 10 % headroom. The 260.0 gr projectile in 0.375" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, Alliant Reloder-16, Alliant Reloder-23 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 .375 Blaser Mag. with the .375 | 260gr | Nosler Partition 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.