Load Specifications
Bullet:.375 | 300gr | Impala RNFP
Bullet Manufacturer:Impala Bullets
Bullet Weight:300 gr
Bullet Diameter:0.375"
Bullet Length:<<locked>>
Caliber:.375 Rem. Ultra Mag. load data
Case Length (l3):2.85"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:117 Grains of Water
Primer Size:Large Rifle Magnum (LRM)
Barrel Length:24"
Max. allowed Pressure:63,817 psi
Recommended Twist Rate:1:16.5
Load data in caliber .375 Rem. Ultra Mag. with .375 | 300gr | Impala RNFP bullet and 101 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, ReloadSwiss RS 70 and Accurate High Country.
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>> | 82% | 56,521 psi | 89% | 2434 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 56,231 psi | 88% | 2484 fps | 98.9% |
| Accurate 3100ᴾ | <<locked>> | 100% | 54,114 psi | 85% | 2533 fps | 99.7% |
| Accurate 4064 | <<locked>> | 84% | 56,739 psi | 89% | 2484 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 56,333 psi | 88% | 2575 fps | 100% |
| Accurate High Country | <<locked>> | 98% | 54,331 psi | 85% | 2654 fps | 97.6% |
| Accurate MAGPROᴾ | <<locked>> | 100% | 55,187 psi | 86% | 2648 fps | 96.4% |
| ADI AR 2208 | <<locked>> | 86% | 55,274 psi | 87% | 2500 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 56,434 psi | 88% | 2605 fps | 98.5% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 54,186 psi | 85% | 2598 fps | 97% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 54,085 psi | 85% | 2608 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 56,333 psi | 88% | 2602 fps | 98.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 56,333 psi | 88% | 2523 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 56,594 psi | 89% | 2543 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 56,043 psi | 88% | 2615 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 90% | 57,580 psi | 90% | 2641 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 55,564 psi | 87% | 2592 fps | 98.5% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 53,069 psi | 83% | 2602 fps | 98.3% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 50,241 psi | 79% | 2546 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 44,135 psi | 69% | 2484 fps | 99.3% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 57,217 psi | 90% | 2713 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 57,435 psi | 90% | 2556 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 48,820 psi | 77% | 2536 fps | 97.4% |
| Bofors RP3 | <<locked>> | 86% | 57,624 psi | 90% | 2543 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 53,069 psi | 83% | 2602 fps | 98.3% |
| Bofors RP7 | <<locked>> | 90% | 56,492 psi | 89% | 2526 fps | 99.1% |
| Hodgdon H380 | <<locked>> | 86% | 57,696 psi | 90% | 2556 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 54,244 psi | 85% | 2569 fps | 99.3% |
| Hodgdon H4350 | <<locked>> | 90% | 57,493 psi | 90% | 2575 fps | 98.9% |
| Hodgdon H4831 | <<locked>> | 98% | 54,186 psi | 85% | 2546 fps | 96.3% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 56,768 psi | 89% | 2582 fps | 96.8% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 56,594 psi | 89% | 2546 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 54,882 psi | 86% | 2536 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 43,294 psi | 68% | 2510 fps | 96.6% |
| Hodgdon Superformance | <<locked>> | 90% | 54,027 psi | 85% | 2598 fps | 99.2% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,767 psi | 58% | 1555 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 55,753 psi | 87% | 2503 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 54,926 psi | 86% | 2487 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 57,348 psi | 90% | 2513 fps | 99.5% |
| IMR 4350 | <<locked>> | 94% | 57,043 psi | 89% | 2552 fps | 99.2% |
| IMR 4451 Enduron | <<locked>> | 90% | 57,682 psi | 90% | 2543 fps | 99.5% |
| IMR 4831 | <<locked>> | 94% | 56,434 psi | 88% | 2566 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 54,607 psi | 86% | 2523 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 56,014 psi | 88% | 2539 fps | 96.9% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 51,721 psi | 81% | 2572 fps | 96.6% |
| Lovex S060 | <<locked>> | 82% | 56,318 psi | 88% | 2467 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 55,622 psi | 87% | 2484 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 54,926 psi | 86% | 2503 fps | 99.8% |
| Lovex S070 | <<locked>> | 92% | 56,246 psi | 88% | 2539 fps | 99.5% |
| Lovex S071ᴾ | <<locked>> | 100% | 45,513 psi | 71% | 2408 fps | 98.8% |
| Norma 201 | <<locked>> | 82% | 56,942 psi | 89% | 2493 fps | 100% |
| Norma 202 | <<locked>> | 82% | 57,276 psi | 90% | 2487 fps | 100% |
| Norma 203B | <<locked>> | 84% | 55,956 psi | 88% | 2533 fps | 100% |
| Norma 204 | <<locked>> | 94% | 57,653 psi | 90% | 2598 fps | 98.5% |
| Norma MRPᴾ | <<locked>> | 100% | 56,014 psi | 88% | 2674 fps | 99.6% |
| Norma URP | <<locked>> | 92% | 54,636 psi | 86% | 2559 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 56,275 psi | 88% | 2552 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 51,967 psi | 81% | 2585 fps | 97% |
| Ramshot Hunter | <<locked>> | 94% | 56,579 psi | 89% | 2605 fps | 99.9% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 46,630 psi | 73% | 2480 fps | 97.6% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,391 psi | 59% | 1591 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 57,334 psi | 90% | 2539 fps | 99.8% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 57,421 psi | 90% | 2605 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 57,029 psi | 89% | 2631 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 55,608 psi | 87% | 2592 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 57,479 psi | 90% | 2661 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 43,134 psi | 68% | 2503 fps | 97.7% |
| Rottweil R 902 | <<locked>> | 84% | 57,638 psi | 90% | 2493 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 57,667 psi | 90% | 2536 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 54,795 psi | 86% | 2530 fps | 97.2% |
| Rottweil R 905 | <<locked>> | 98% | 55,071 psi | 86% | 2585 fps | 98.5% |
| Rottweil R 907 | <<locked>> | 90% | 56,492 psi | 89% | 2526 fps | 99.1% |
| Shooters World Long Rifle | <<locked>> | 90% | 54,926 psi | 86% | 2503 fps | 99.8% |
| Shooters World Precision | <<locked>> | 84% | 55,622 psi | 87% | 2484 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 56,246 psi | 88% | 2539 fps | 99.5% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 54,882 psi | 86% | 2543 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 56,173 psi | 88% | 2516 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 57,392 psi | 90% | 2425 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 54,679 psi | 86% | 2385 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 54,592 psi | 86% | 2457 fps | 99.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 54,578 psi | 86% | 2579 fps | 98.4% |
| Somchem S335 | <<locked>> | 82% | 57,188 psi | 90% | 2421 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 57,319 psi | 90% | 2530 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 56,565 psi | 89% | 2523 fps | 96.7% |
| Somchem S365 | <<locked>> | 96% | 57,087 psi | 89% | 2602 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 56,086 psi | 88% | 2566 fps | 99.1% |
| Vihtavuori N133 | <<locked>> | 82% | 57,740 psi | 90% | 2405 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 57,696 psi | 90% | 2451 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 54,360 psi | 85% | 2425 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 55,085 psi | 86% | 2467 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 56,521 psi | 89% | 2546 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 51,547 psi | 81% | 2490 fps | 98.3% |
| Vihtavuori N540 | <<locked>> | 84% | 56,043 psi | 88% | 2467 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 55,811 psi | 87% | 2556 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 56,420 psi | 88% | 2612 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 56,391 psi | 88% | 2661 fps | 97.2% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 55,912 psi | 88% | 2516 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 54,433 psi | 85% | 2569 fps | 99.4% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 45,730 psi | 72% | 2602 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 56,188 psi | 88% | 2523 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 55,753 psi | 87% | 2552 fps | 98.4% |
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 2495 | <<locked>> | 80% | 53,316 psi | 84% | 2398 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 49,617 psi | 78% | 2392 fps | 98% |
| Accurate 3100 | <<locked>> | 84% | 32,837 psi | 51% | 2175 fps | 95.5% |
| Accurate 4064 | <<locked>> | 80% | 50,444 psi | 79% | 2405 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 38,421 psi | 60% | 2300 fps | 98.7% |
| Accurate High Country | 84.8 gr | 92% | 44,672 psi | 70% | 2500 fps | 95.4% |
| Accurate MAGPRO | <<locked>> | 98% | 51,605 psi | 81% | 2595 fps | 95.6% |
| ADI AR 2208 | <<locked>> | 80% | 46,470 psi | 73% | 2375 fps | 99.9% |
| ADI AR 2209 | <<locked>> | 88% | 41,553 psi | 65% | 2365 fps | 95.2% |
| ADI AR 2213 | <<locked>> | 96% | 47,790 psi | 75% | 2497 fps | 95.4% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 50,734 psi | 80% | 2562 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 41,611 psi | 65% | 2365 fps | 95.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 47,152 psi | 74% | 2398 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 50,067 psi | 78% | 2454 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 36,970 psi | 58% | 2300 fps | 98.7% |
| Alliant Reloder-17 | <<locked>> | 80% | 41,510 psi | 65% | 2405 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 41,220 psi | 65% | 2362 fps | 95.3% |
| Alliant Reloder-22 | <<locked>> | 92% | 41,365 psi | 65% | 2405 fps | 95.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 27,934 psi | 44% | 2106 fps | 97.1% |
| Alliant Reloder-25 | <<locked>> | 88% | 31,256 psi | 49% | 2201 fps | 95.1% |
| Alliant Reloder-26 | 75.9 gr | 80% | 29,573 psi | 46% | 2198 fps | 95.3% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 53,925 psi | 85% | 2513 fps | 100% |
| Bofors RP15 | <<locked>> | 94% | 40,843 psi | 64% | 2395 fps | 95.2% |
| Bofors RP3 | <<locked>> | 80% | 47,805 psi | 75% | 2411 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 41,365 psi | 65% | 2405 fps | 95.6% |
| Bofors RP7 | <<locked>> | 80% | 42,076 psi | 66% | 2300 fps | 96.6% |
| Hodgdon H380 | <<locked>> | 80% | 47,921 psi | 75% | 2421 fps | 99.7% |
| Hodgdon H414 | <<locked>> | 80% | 39,784 psi | 62% | 2329 fps | 96.7% |
| Hodgdon H4350 | <<locked>> | 80% | 42,482 psi | 67% | 2339 fps | 96% |
| Hodgdon H4831 | <<locked>> | 96% | 50,879 psi | 80% | 2497 fps | 95.6% |
| Hodgdon H4831 SC | <<locked>> | 96% | 50,009 psi | 78% | 2487 fps | 95.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 34,650 psi | 54% | 2208 fps | 99.2% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 51,576 psi | 81% | 2493 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 40,770 psi | 64% | 2454 fps | 95.7% |
| Hodgdon Superformance | <<locked>> | 80% | 38,609 psi | 61% | 2336 fps | 95.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,543 psi | 43% | 1388 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 52,402 psi | 82% | 2461 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 48,849 psi | 77% | 2402 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 50,821 psi | 80% | 2421 fps | 98.8% |
| IMR 4350 | <<locked>> | 80% | 37,710 psi | 59% | 2238 fps | 95.3% |
| IMR 4451 Enduron | <<locked>> | 80% | 43,120 psi | 68% | 2323 fps | 97.3% |
| IMR 4831 | <<locked>> | 80% | 36,869 psi | 58% | 2257 fps | 98.5% |
| IMR 4895 | <<locked>> | 80% | 51,358 psi | 80% | 2480 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 49,763 psi | 78% | 2448 fps | 95.6% |
| IMR 7828 SSC | <<locked>> | 98% | 48,544 psi | 76% | 2523 fps | 95.8% |
| Lovex S060 | <<locked>> | 80% | 53,142 psi | 83% | 2428 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 49,371 psi | 77% | 2402 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 41,205 psi | 65% | 2287 fps | 98.2% |
| Lovex S070 | <<locked>> | 80% | 39,537 psi | 62% | 2274 fps | 96.8% |
| Lovex S071 | <<locked>> | 88% | 32,053 psi | 50% | 2156 fps | 95.2% |
| Norma 201 | <<locked>> | 80% | 53,751 psi | 84% | 2451 fps | 100% |
| Norma 202 | <<locked>> | 80% | 54,027 psi | 85% | 2444 fps | 100% |
| Norma 203B | <<locked>> | 80% | 49,472 psi | 78% | 2444 fps | 100% |
| Norma 204 | <<locked>> | 84% | 41,945 psi | 66% | 2356 fps | 95.3% |
| Norma MRP | <<locked>> | 86% | 35,853 psi | 56% | 2320 fps | 95.2% |
| Norma URP | <<locked>> | 80% | 37,826 psi | 59% | 2290 fps | 98.5% |
| Ramshot Big Game | <<locked>> | 80% | 49,588 psi | 78% | 2464 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 45,411 psi | 71% | 2477 fps | 95.2% |
| Ramshot Hunter | <<locked>> | 80% | 36,550 psi | 57% | 2277 fps | 96.6% |
| Ramshot Magnum | <<locked>> | 94% | 38,189 psi | 60% | 2326 fps | 95% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,166 psi | 44% | 1424 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 47,732 psi | 75% | 2402 fps | 98.8% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 53,679 psi | 84% | 2556 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 43,903 psi | 69% | 2451 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 37,739 psi | 59% | 2313 fps | 98.4% |
| ReloadSwiss RS 70 | 75.3 gr | 80% | 36,666 psi | 57% | 2316 fps | 97.8% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 37,956 psi | 59% | 2392 fps | 95.7% |
| Rottweil R 902 | <<locked>> | 80% | 51,387 psi | 81% | 2411 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 45,237 psi | 71% | 2369 fps | 100% |
| Rottweil R 904 | <<locked>> | 90% | 45,774 psi | 72% | 2392 fps | 95.2% |
| Rottweil R 905 | <<locked>> | 88% | 40,321 psi | 63% | 2349 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 80% | 42,076 psi | 66% | 2300 fps | 96.6% |
| Shooters World Long Rifle | <<locked>> | 80% | 41,205 psi | 65% | 2287 fps | 98.2% |
| Shooters World Precision | <<locked>> | 80% | 49,371 psi | 77% | 2402 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 39,537 psi | 62% | 2274 fps | 96.8% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 45,498 psi | 71% | 2408 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 52,692 psi | 83% | 2470 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 54,114 psi | 85% | 2385 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 45,948 psi | 72% | 2277 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 40,350 psi | 63% | 2238 fps | 96.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 39,929 psi | 63% | 2343 fps | 95.1% |
| Somchem S335 | <<locked>> | 80% | 54,041 psi | 85% | 2385 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 45,339 psi | 71% | 2365 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 49,821 psi | 78% | 2428 fps | 95.3% |
| Somchem S365 | <<locked>> | 80% | 34,461 psi | 54% | 2260 fps | 99.9% |
| Somchem S385 | <<locked>> | 86% | 38,841 psi | 61% | 2293 fps | 95.7% |
| Vihtavuori N133 | <<locked>> | 80% | 54,462 psi | 85% | 2365 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 51,329 psi | 80% | 2375 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 51,271 psi | 80% | 2388 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 43,221 psi | 68% | 2303 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 39,044 psi | 61% | 2283 fps | 98.7% |
| Vihtavuori N165 | <<locked>> | 92% | 40,248 psi | 63% | 2310 fps | 95.7% |
| Vihtavuori N540 | <<locked>> | 80% | 49,676 psi | 78% | 2388 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 38,783 psi | 61% | 2290 fps | 98.5% |
| Vihtavuori N555 | <<locked>> | 80% | 30,719 psi | 48% | 2175 fps | 97.3% |
| Vihtavuori N560 | <<locked>> | 96% | 49,705 psi | 78% | 2559 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 38,072 psi | 60% | 2254 fps | 99.8% |
| Winchester 760 | <<locked>> | 80% | 39,885 psi | 63% | 2333 fps | 96.7% |
| Winchester StaBALL HD | <<locked>> | 80% | 25,063 psi | 39% | 2093 fps | 96.2% |
| Winchester StaBALL Match | <<locked>> | 80% | 52,910 psi | 83% | 2480 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 42,975 psi | 67% | 2362 fps | 95.7% |
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 101 powders for .375 Rem. Ultra Mag. loaded with the .375 | 300gr | Impala RNFP. Alliant Reloder-26 delivers the highest muzzle velocity at 2,713 fps; across all powders the maximum-charge window runs from 1,555 fps to 2,713 fps. Accurate 3100 gives the best case fill at 100 %, and 101 of the 101 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 58–90 %, 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. Accurate 3100, Accurate MAGPRO, ADI AR 2213 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-26, ReloadSwiss RS 70, Accurate High Country rank at the top here: for .375 Rem. Ultra Mag. with the .375 | 300gr | Impala RNFP 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.