Load Specifications
Load data in caliber .375 Fl. Mag. N.E. with .375 | 305gr | Hammer Stone Hammer bullet and 47 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Somchem S365, ReloadSwiss RS 70 and Alliant Reloder-17.
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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Max Load - Barrel Length: 23.62"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 82% | 41,597 psi | 88% | 2218 fps | 100% |
| Accurate 4064 | <<locked>> | 84% | 41,829 psi | 89% | 2257 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 40,059 psi | 85% | 2297 fps | 97.7% |
| ADI AR 2208 | <<locked>> | 84% | 40,959 psi | 87% | 2228 fps | 98.2% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 41,104 psi | 87% | 2343 fps | 98.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 40,480 psi | 86% | 2247 fps | 99.3% |
| Alliant Reloder-15 | <<locked>> | 82% | 40,959 psi | 87% | 2257 fps | 98.4% |
| Alliant Reloder-16 | <<locked>> | 94% | 42,656 psi | 90% | 2352 fps | 98.4% |
| Alliant Reloder-17 | <<locked>> | 88% | 39,871 psi | 85% | 2326 fps | 99.1% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 36,347 psi | 77% | 2264 fps | 98.2% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 40,190 psi | 85% | 2392 fps | 97.1% |
| Bofors RP3 | <<locked>> | 84% | 40,190 psi | 85% | 2254 fps | 99.3% |
| Hodgdon H380 | <<locked>> | 84% | 41,075 psi | 87% | 2257 fps | 97.3% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 41,887 psi | 89% | 2300 fps | 99.3% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 41,452 psi | 88% | 2300 fps | 99.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,244 psi | 75% | 1450 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 40,495 psi | 86% | 2211 fps | 98.3% |
| IMR 4831 | <<locked>> | 94% | 41,176 psi | 87% | 2300 fps | 98% |
| IMR 4895 | <<locked>> | 82% | 41,959 psi | 89% | 2283 fps | 99% |
| Lovex S062 | <<locked>> | 82% | 40,451 psi | 86% | 2218 fps | 99.5% |
| Lovex S065 | <<locked>> | 90% | 42,322 psi | 90% | 2254 fps | 96.7% |
| Norma 203B | <<locked>> | 82% | 40,350 psi | 86% | 2251 fps | 98.7% |
| Norma URP | <<locked>> | 92% | 40,306 psi | 86% | 2293 fps | 97.6% |
| Ramshot Big Game | <<locked>> | 84% | 42,482 psi | 90% | 2310 fps | 99% |
| Ramshot Hunter | <<locked>> | 94% | 42,061 psi | 89% | 2329 fps | 96.2% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,737 psi | 76% | 1486 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 41,698 psi | 88% | 2244 fps | 95.7% |
| ReloadSwiss RS 60 | <<locked>> | 88% | 42,525 psi | 90% | 2382 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 42,467 psi | 90% | 2362 fps | 97.9% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 40,248 psi | 85% | 2326 fps | 96.6% |
| Rottweil R 902 | <<locked>> | 82% | 42,279 psi | 90% | 2228 fps | 99.7% |
| Rottweil R 903 | <<locked>> | 86% | 40,248 psi | 85% | 2251 fps | 99.2% |
| Shooters World Long Rifle | <<locked>> | 90% | 42,322 psi | 90% | 2254 fps | 96.7% |
| Shooters World Precision | <<locked>> | 82% | 40,451 psi | 86% | 2218 fps | 99.5% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 41,394 psi | 88% | 2297 fps | 98.8% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 40,553 psi | 86% | 2152 fps | 100% |
| Somchem S355 | <<locked>> | 86% | 41,089 psi | 87% | 2251 fps | 99.2% |
| Somchem S365 | <<locked>> | 96% | 40,814 psi | 87% | 2343 fps | 99.9% |
| Vihtavuori N135 | <<locked>> | 82% | 41,582 psi | 88% | 2211 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 42,279 psi | 90% | 2221 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 41,771 psi | 89% | 2238 fps | 99.8% |
| Vihtavuori N160 | <<locked>> | 92% | 42,221 psi | 90% | 2293 fps | 97.9% |
| Vihtavuori N540 | <<locked>> | 82% | 40,770 psi | 86% | 2215 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 41,539 psi | 88% | 2300 fps | 97.6% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 39,218 psi | 83% | 2326 fps | 98.1% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 42,438 psi | 90% | 2280 fps | 99.4% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 32,460 psi | 69% | 2251 fps | 97.6% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 23.62"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 80% | 39,015 psi | 83% | 2175 fps | 100% |
| Accurate 4064 | <<locked>> | 80% | 36,912 psi | 78% | 2172 fps | 100% |
| Accurate 4350 | <<locked>> | 86% | 32,721 psi | 69% | 2152 fps | 95.4% |
| ADI AR 2208 | <<locked>> | 80% | 36,260 psi | 77% | 2139 fps | 97.1% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 38,493 psi | 82% | 2290 fps | 97.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 35,781 psi | 76% | 2159 fps | 98.5% |
| Alliant Reloder-15 | <<locked>> | 80% | 38,377 psi | 81% | 2211 fps | 97.9% |
| Alliant Reloder-16 | <<locked>> | 86% | 33,460 psi | 71% | 2162 fps | 95.5% |
| Alliant Reloder-17 | 60.9 gr | 80% | 30,806 psi | 65% | 2129 fps | 96.3% |
| Alliant Reloder-23 | <<locked>> | 92% | 28,703 psi | 61% | 2080 fps | 95% |
| Alliant Reloder-26 | <<locked>> | 96% | 34,954 psi | 74% | 2280 fps | 95.1% |
| Bofors RP3 | <<locked>> | 80% | 35,114 psi | 74% | 2159 fps | 98.4% |
| Hodgdon H380 | <<locked>> | 80% | 36,143 psi | 77% | 2162 fps | 95.9% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 28,747 psi | 61% | 2031 fps | 95.5% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 38,783 psi | 82% | 2254 fps | 99.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,223 psi | 56% | 1293 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 38,058 psi | 81% | 2169 fps | 97.8% |
| IMR 4831 | <<locked>> | 86% | 31,879 psi | 68% | 2119 fps | 95.1% |
| IMR 4895 | <<locked>> | 80% | 39,247 psi | 83% | 2238 fps | 98.6% |
| Lovex S062 | <<locked>> | 80% | 37,869 psi | 80% | 2172 fps | 99.2% |
| Lovex S065 | <<locked>> | 86% | 37,405 psi | 79% | 2165 fps | 95.3% |
| Norma 203B | <<locked>> | 80% | 37,768 psi | 80% | 2201 fps | 98.2% |
| Norma URP | <<locked>> | 86% | 33,330 psi | 71% | 2156 fps | 95.4% |
| Ramshot Big Game | <<locked>> | 80% | 37,144 psi | 79% | 2211 fps | 97.9% |
| Ramshot Hunter | <<locked>> | 92% | 39,465 psi | 84% | 2283 fps | 95.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,571 psi | 56% | 1325 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 39,131 psi | 83% | 2198 fps | 95% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 32,808 psi | 70% | 2188 fps | 99.2% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 34,838 psi | 74% | 2218 fps | 95.7% |
| ReloadSwiss RS 70 | 69.5 gr | 90% | 37,608 psi | 80% | 2270 fps | 95.6% |
| Rottweil R 902 | <<locked>> | 80% | 39,711 psi | 84% | 2185 fps | 99.4% |
| Rottweil R 903 | <<locked>> | 80% | 33,156 psi | 70% | 2113 fps | 97.7% |
| Shooters World Long Rifle | <<locked>> | 86% | 37,405 psi | 79% | 2165 fps | 95.3% |
| Shooters World Precision | <<locked>> | 80% | 37,869 psi | 80% | 2172 fps | 99.2% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 34,040 psi | 72% | 2156 fps | 97.1% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 35,911 psi | 76% | 2077 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 34,185 psi | 73% | 2123 fps | 97.7% |
| Somchem S365 | 59.1 gr | 82% | 26,208 psi | 56% | 2018 fps | 95.9% |
| Vihtavuori N135 | <<locked>> | 80% | 39,204 psi | 83% | 2172 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 39,755 psi | 84% | 2178 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 32,372 psi | 69% | 2067 fps | 98.4% |
| Vihtavuori N160 | <<locked>> | 84% | 32,692 psi | 69% | 2113 fps | 95% |
| Vihtavuori N540 | <<locked>> | 80% | 38,203 psi | 81% | 2172 fps | 100% |
| Vihtavuori N550 | <<locked>> | 86% | 34,127 psi | 72% | 2159 fps | 95.4% |
| Vihtavuori N555 | <<locked>> | 92% | 30,414 psi | 65% | 2142 fps | 95.1% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 28,747 psi | 61% | 2001 fps | 95.5% |
| Winchester StaBALL HD | <<locked>> | 96% | 28,660 psi | 61% | 2142 fps | 95.2% |
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 47 powders for .375 Fl. Mag. N.E. loaded with the .375 | 305gr | Hammer Stone Hammer. Alliant Reloder-26 delivers the highest muzzle velocity at 2,392 fps; across all powders the maximum-charge window runs from 1,450 fps to 2,392 fps. Alliant Reloder-23 gives the best case fill at 100 %, and 47 of the 47 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (325 MPa), the top charges use 69–90 %, 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. Alliant Reloder-23, Alliant Reloder-26, Hodgdon TrailBoss 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. Somchem S365, ReloadSwiss RS 70, Alliant Reloder-17 rank at the top here: for .375 Fl. Mag. N.E. with the .375 | 305gr | Hammer Stone Hammer 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.