Load Specifications
Bullet Manufacturer:Hammer
Bullet Weight:305 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:1:6.0
Load data in caliber .375 Rem. Ultra Mag. with .375 | 305gr | Hammer Claw Hammer bullet and 105 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 70, Alliant Reloder-26 and Hodgdon Superformance.
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% | 57,305 psi | 90% | 2454 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 55,027 psi | 86% | 2477 fps | 99.1% |
| Accurate 3100ᴾ | <<locked>> | 100% | 52,272 psi | 82% | 2516 fps | 99.8% |
| Accurate 4064 | <<locked>> | 86% | 57,653 psi | 90% | 2503 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 54,723 psi | 86% | 2562 fps | 100% |
| Accurate MAGPROᴾ | <<locked>> | 100% | 54,346 psi | 85% | 2644 fps | 96.7% |
| ADI AR 2206H | <<locked>> | 82% | 56,652 psi | 89% | 2533 fps | 100% |
| ADI AR 2208 | <<locked>> | 86% | 54,302 psi | 85% | 2493 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 55,608 psi | 87% | 2598 fps | 98.7% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 53,258 psi | 83% | 2592 fps | 97.3% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 57,276 psi | 90% | 2651 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 54,969 psi | 86% | 2513 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 55,288 psi | 87% | 2533 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 55,259 psi | 87% | 2608 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 90% | 56,637 psi | 89% | 2628 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 54,853 psi | 86% | 2589 fps | 98.7% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 51,938 psi | 81% | 2592 fps | 98.5% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 49,182 psi | 77% | 2533 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 42,757 psi | 67% | 2467 fps | 99.4% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 56,347 psi | 88% | 2707 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 56,492 psi | 89% | 2549 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 47,587 psi | 75% | 2523 fps | 97.6% |
| Bofors RP3 | <<locked>> | 86% | 55,941 psi | 88% | 2530 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 51,938 psi | 81% | 2592 fps | 98.5% |
| Bofors RP7 | <<locked>> | 90% | 55,201 psi | 87% | 2516 fps | 99.3% |
| Hodgdon H380 | <<locked>> | 86% | 56,260 psi | 88% | 2546 fps | 100% |
| Hodgdon H414 | <<locked>> | 92% | 56,811 psi | 89% | 2608 fps | 99.7% |
| Hodgdon H4350 | <<locked>> | 90% | 56,695 psi | 89% | 2569 fps | 99.1% |
| Hodgdon H4831ᴾ | <<locked>> | 100% | 57,174 psi | 90% | 2595 fps | 97.4% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 55,912 psi | 88% | 2579 fps | 97.2% |
| Hodgdon H4895 | <<locked>> | 82% | 57,305 psi | 90% | 2539 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 55,593 psi | 87% | 2536 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 57,551 psi | 90% | 2572 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 41,887 psi | 66% | 2493 fps | 96.8% |
| Hodgdon Superformance | <<locked>> | 92% | 57,203 psi | 90% | 2644 fps | 99.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,332 psi | 57% | 1552 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 54,665 psi | 86% | 2497 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 57,232 psi | 90% | 2520 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 56,405 psi | 88% | 2510 fps | 99.6% |
| IMR 4350 | <<locked>> | 94% | 56,072 psi | 88% | 2546 fps | 99.4% |
| IMR 4451 Enduron | <<locked>> | 90% | 56,971 psi | 89% | 2543 fps | 99.6% |
| IMR 4831 | <<locked>> | 94% | 55,042 psi | 86% | 2552 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 56,724 psi | 89% | 2556 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 55,143 psi | 86% | 2536 fps | 97.2% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 50,691 psi | 79% | 2566 fps | 96.9% |
| Lovex D073.6 | <<locked>> | 82% | 57,014 psi | 89% | 2503 fps | 100% |
| Lovex S060 | <<locked>> | 82% | 55,506 psi | 87% | 2464 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 57,479 psi | 90% | 2513 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 56,840 psi | 89% | 2533 fps | 100% |
| Lovex S070 | <<locked>> | 92% | 54,868 psi | 86% | 2530 fps | 99.6% |
| Lovex S071ᴾ | <<locked>> | 100% | 43,482 psi | 68% | 2388 fps | 98.8% |
| Norma 201 | <<locked>> | 82% | 55,405 psi | 87% | 2480 fps | 100% |
| Norma 202 | <<locked>> | 82% | 56,086 psi | 88% | 2477 fps | 100% |
| Norma 203B | <<locked>> | 84% | 54,578 psi | 86% | 2520 fps | 100% |
| Norma 204 | <<locked>> | 94% | 57,058 psi | 89% | 2595 fps | 98.8% |
| Norma MRPᴾ | <<locked>> | 100% | 55,259 psi | 87% | 2667 fps | 99.7% |
| Norma URP | <<locked>> | 94% | 56,855 psi | 89% | 2592 fps | 100% |
| Ramshot Big Game | <<locked>> | 84% | 55,317 psi | 87% | 2543 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 50,937 psi | 80% | 2579 fps | 97.3% |
| Ramshot Hunter | <<locked>> | 94% | 55,782 psi | 87% | 2598 fps | 99.9% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 45,382 psi | 71% | 2470 fps | 97.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,999 psi | 58% | 1591 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 56,347 psi | 88% | 2533 fps | 99.8% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 56,246 psi | 88% | 2592 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 56,173 psi | 88% | 2621 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 54,520 psi | 85% | 2582 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 56,710 psi | 89% | 2654 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 41,669 psi | 65% | 2487 fps | 97.8% |
| Rottweil R 902 | <<locked>> | 84% | 56,115 psi | 88% | 2480 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 55,999 psi | 88% | 2523 fps | 100% |
| Rottweil R 904 | <<locked>> | 98% | 57,493 psi | 90% | 2572 fps | 98.1% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 57,667 psi | 90% | 2625 fps | 99.1% |
| Rottweil R 907 | <<locked>> | 90% | 55,201 psi | 87% | 2516 fps | 99.3% |
| Shooters World Long Rifle | <<locked>> | 92% | 56,840 psi | 89% | 2533 fps | 100% |
| Shooters World Match Rifle | <<locked>> | 82% | 57,014 psi | 89% | 2503 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 57,479 psi | 90% | 2513 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 54,868 psi | 86% | 2530 fps | 99.6% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 57,479 psi | 90% | 2575 fps | 100% |
| SNPE Vectan SP 3 | <<locked>> | 82% | 56,623 psi | 89% | 2395 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 55,042 psi | 86% | 2507 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 56,159 psi | 88% | 2415 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 57,058 psi | 89% | 2415 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 56,695 psi | 89% | 2493 fps | 99.6% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 57,159 psi | 90% | 2618 fps | 99.1% |
| Somchem S335 | <<locked>> | 82% | 55,956 psi | 88% | 2415 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 57,522 psi | 90% | 2523 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 55,883 psi | 88% | 2520 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 55,666 psi | 87% | 2520 fps | 97% |
| Somchem S365 | <<locked>> | 96% | 56,057 psi | 88% | 2592 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 54,795 psi | 86% | 2556 fps | 99.3% |
| Vihtavuori N133 | <<locked>> | 82% | 56,623 psi | 89% | 2395 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 56,217 psi | 88% | 2438 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 56,666 psi | 89% | 2457 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 57,290 psi | 90% | 2493 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 55,637 psi | 87% | 2543 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 50,444 psi | 79% | 2484 fps | 98.5% |
| Vihtavuori N540 | <<locked>> | 84% | 54,853 psi | 86% | 2457 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 54,708 psi | 86% | 2546 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 54,897 psi | 86% | 2598 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 55,680 psi | 87% | 2657 fps | 97.6% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 55,143 psi | 86% | 2510 fps | 100% |
| Winchester 760 | <<locked>> | 92% | 57,029 psi | 89% | 2608 fps | 99.7% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 44,309 psi | 69% | 2585 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 55,114 psi | 86% | 2513 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 54,911 psi | 86% | 2549 fps | 98.6% |
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% | 50,473 psi | 79% | 2375 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 48,298 psi | 76% | 2382 fps | 98.1% |
| Accurate 3100 | <<locked>> | 86% | 32,503 psi | 51% | 2182 fps | 95.9% |
| Accurate 4064 | <<locked>> | 80% | 47,805 psi | 75% | 2382 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 36,289 psi | 57% | 2270 fps | 98.6% |
| Accurate MAGPRO | <<locked>> | 96% | 47,152 psi | 74% | 2533 fps | 95% |
| ADI AR 2206H | <<locked>> | 80% | 53,258 psi | 83% | 2487 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 45,136 psi | 71% | 2362 fps | 99.9% |
| ADI AR 2209 | <<locked>> | 88% | 40,248 psi | 63% | 2349 fps | 95.3% |
| ADI AR 2213 | <<locked>> | 96% | 46,572 psi | 73% | 2487 fps | 95.7% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 49,676 psi | 78% | 2549 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 45,643 psi | 72% | 2382 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 48,762 psi | 76% | 2444 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 35,549 psi | 56% | 2280 fps | 98.7% |
| Alliant Reloder-17 | <<locked>> | 80% | 40,030 psi | 63% | 2388 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 39,842 psi | 62% | 2346 fps | 95.4% |
| Alliant Reloder-22 | <<locked>> | 92% | 39,958 psi | 63% | 2388 fps | 95.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 26,005 psi | 41% | 2070 fps | 96.6% |
| Alliant Reloder-25 | <<locked>> | 90% | 31,299 psi | 49% | 2218 fps | 95.7% |
| Alliant Reloder-26 | 80.1 gr | 82% | 29,559 psi | 46% | 2215 fps | 95.9% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 52,939 psi | 83% | 2503 fps | 100% |
| Bofors RP15 | <<locked>> | 94% | 39,291 psi | 62% | 2375 fps | 95.2% |
| Bofors RP3 | <<locked>> | 80% | 45,934 psi | 72% | 2395 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 39,958 psi | 63% | 2388 fps | 95.6% |
| Bofors RP7 | <<locked>> | 80% | 40,437 psi | 63% | 2280 fps | 96.6% |
| Hodgdon H380 | <<locked>> | 80% | 46,166 psi | 72% | 2402 fps | 99.7% |
| Hodgdon H414 | <<locked>> | 80% | 38,276 psi | 60% | 2313 fps | 96.7% |
| Hodgdon H4350 | <<locked>> | 80% | 41,263 psi | 65% | 2329 fps | 96.1% |
| Hodgdon H4831 | <<locked>> | 94% | 46,818 psi | 73% | 2444 fps | 95.1% |
| Hodgdon H4831 SC | <<locked>> | 96% | 48,878 psi | 77% | 2477 fps | 95.7% |
| Hodgdon H4895 | <<locked>> | 80% | 53,838 psi | 84% | 2497 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 32,996 psi | 52% | 2185 fps | 99.1% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 50,372 psi | 79% | 2480 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 39,334 psi | 62% | 2441 fps | 95.8% |
| Hodgdon Superformance | 80.6 gr | 80% | 37,188 psi | 58% | 2316 fps | 95.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,166 psi | 43% | 1388 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 51,372 psi | 81% | 2451 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 47,485 psi | 74% | 2388 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 49,864 psi | 78% | 2418 fps | 98.9% |
| IMR 4350 | <<locked>> | 80% | 36,230 psi | 57% | 2221 fps | 95.3% |
| IMR 4451 Enduron | <<locked>> | 80% | 41,887 psi | 66% | 2310 fps | 97.4% |
| IMR 4831 | <<locked>> | 80% | 34,925 psi | 55% | 2231 fps | 98.3% |
| IMR 4895 | <<locked>> | 80% | 50,024 psi | 78% | 2467 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 45,774 psi | 72% | 2392 fps | 95% |
| IMR 7828 SSC | <<locked>> | 96% | 44,498 psi | 70% | 2464 fps | 95.2% |
| Lovex D073.6 | <<locked>> | 80% | 53,490 psi | 84% | 2464 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 52,199 psi | 82% | 2421 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 47,747 psi | 75% | 2388 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 39,421 psi | 62% | 2267 fps | 98.1% |
| Lovex S070 | <<locked>> | 80% | 37,681 psi | 59% | 2251 fps | 96.7% |
| Lovex S071 | <<locked>> | 90% | 31,560 psi | 49% | 2162 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 52,054 psi | 82% | 2438 fps | 100% |
| Norma 202 | <<locked>> | 80% | 52,649 psi | 83% | 2434 fps | 100% |
| Norma 203B | <<locked>> | 80% | 48,124 psi | 75% | 2431 fps | 100% |
| Norma 204 | <<locked>> | 84% | 40,669 psi | 64% | 2343 fps | 95.4% |
| Norma MRP | <<locked>> | 86% | 34,171 psi | 54% | 2297 fps | 95% |
| Norma URP | <<locked>> | 80% | 36,158 psi | 57% | 2267 fps | 98.4% |
| Ramshot Big Game | <<locked>> | 80% | 48,269 psi | 76% | 2451 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 44,135 psi | 69% | 2467 fps | 95.5% |
| Ramshot Hunter | <<locked>> | 80% | 34,954 psi | 55% | 2254 fps | 96.5% |
| Ramshot Magnum | <<locked>> | 94% | 36,535 psi | 57% | 2306 fps | 95% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,702 psi | 43% | 1424 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 46,340 psi | 73% | 2388 fps | 98.9% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 52,489 psi | 82% | 2546 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 42,525 psi | 67% | 2434 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 35,882 psi | 56% | 2287 fps | 98.3% |
| ReloadSwiss RS 70 | 77.4 gr | 80% | 35,056 psi | 55% | 2293 fps | 97.7% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 36,260 psi | 57% | 2365 fps | 95.7% |
| Rottweil R 902 | <<locked>> | 80% | 49,632 psi | 78% | 2398 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 43,221 psi | 68% | 2346 fps | 100% |
| Rottweil R 904 | <<locked>> | 90% | 44,556 psi | 70% | 2382 fps | 95.4% |
| Rottweil R 905 | <<locked>> | 88% | 38,798 psi | 61% | 2329 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 80% | 40,437 psi | 63% | 2280 fps | 96.6% |
| Shooters World Long Rifle | <<locked>> | 80% | 39,421 psi | 62% | 2267 fps | 98.1% |
| Shooters World Match Rifle | <<locked>> | 80% | 53,490 psi | 84% | 2464 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 47,747 psi | 75% | 2388 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 37,681 psi | 59% | 2251 fps | 96.7% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 44,150 psi | 69% | 2392 fps | 100% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 53,330 psi | 84% | 2359 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 51,576 psi | 81% | 2461 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 52,808 psi | 83% | 2375 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 44,614 psi | 70% | 2264 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 38,537 psi | 60% | 2218 fps | 96.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 38,421 psi | 60% | 2326 fps | 95.1% |
| Somchem S335 | <<locked>> | 80% | 52,591 psi | 82% | 2375 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 53,853 psi | 84% | 2477 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 43,584 psi | 68% | 2346 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 48,704 psi | 76% | 2421 fps | 95.5% |
| Somchem S365 | <<locked>> | 80% | 32,619 psi | 51% | 2231 fps | 99.8% |
| Somchem S385 | <<locked>> | 86% | 37,072 psi | 58% | 2267 fps | 95.6% |
| Vihtavuori N133 | <<locked>> | 80% | 53,330 psi | 84% | 2359 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 49,719 psi | 78% | 2362 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 49,980 psi | 78% | 2375 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 41,597 psi | 65% | 2283 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 37,550 psi | 59% | 2267 fps | 98.7% |
| Vihtavuori N165 | <<locked>> | 92% | 38,870 psi | 61% | 2297 fps | 95.8% |
| Vihtavuori N540 | <<locked>> | 80% | 48,153 psi | 75% | 2372 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 36,927 psi | 58% | 2267 fps | 98.4% |
| Vihtavuori N555 | <<locked>> | 80% | 28,369 psi | 44% | 2133 fps | 96.7% |
| Vihtavuori N560 | <<locked>> | 94% | 45,411 psi | 71% | 2497 fps | 95.1% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 36,724 psi | 58% | 2238 fps | 99.8% |
| Winchester 760 | <<locked>> | 80% | 38,276 psi | 60% | 2313 fps | 96.7% |
| Winchester StaBALL HD | <<locked>> | 80% | 22,887 psi | 36% | 2037 fps | 95% |
| Winchester StaBALL Match | <<locked>> | 80% | 51,576 psi | 81% | 2467 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 38,856 psi | 61% | 2300 fps | 95% |
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 112 powders for .375 Rem. Ultra Mag. loaded with the .375 | 305gr | Hammer Claw Hammer . Alliant Reloder-26 delivers the highest muzzle velocity at 2,707 fps; across all powders the maximum-charge window runs from 1,552 fps to 2,707 fps. Accurate 3100 gives the best case fill at 100 %, and 112 of the 112 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 47–90 %, leaving at least 10 % headroom. The 305.0 gr projectile in 0.375" calls for a 1:6.0 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. ReloadSwiss RS 70, Alliant Reloder-26, Hodgdon Superformance rank at the top here: for .375 Rem. Ultra Mag. with the .375 | 305gr | Hammer Claw Hammer they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, ADI AR 2217, ADI AR 2225, Baschieri & Pellagri 109 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.