Load Specifications
Load data in caliber .375 Fl. Mag. N.E. with .375 | 300gr | Swift A-Frame bullet and 44 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-17 and ReloadSwiss RS 62.
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% | 42,395 psi | 90% | 2254 fps | 100% |
| Accurate 4064 | <<locked>> | 84% | 42,540 psi | 90% | 2293 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 41,017 psi | 87% | 2339 fps | 97.9% |
| ADI AR 2208 | <<locked>> | 84% | 41,553 psi | 88% | 2264 fps | 98.3% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 41,872 psi | 89% | 2385 fps | 98.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 41,234 psi | 87% | 2287 fps | 99.4% |
| Alliant Reloder-15 | <<locked>> | 82% | 41,597 psi | 88% | 2297 fps | 98.5% |
| Alliant Reloder-16 | <<locked>> | 92% | 40,857 psi | 87% | 2346 fps | 98% |
| Alliant Reloder-17 | <<locked>> | 88% | 40,640 psi | 86% | 2372 fps | 99.2% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 37,014 psi | 79% | 2303 fps | 98.4% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 41,046 psi | 87% | 2438 fps | 97.4% |
| Bofors RP3 | <<locked>> | 84% | 40,930 psi | 87% | 2293 fps | 99.4% |
| Hodgdon H380 | <<locked>> | 84% | 41,930 psi | 89% | 2300 fps | 97.5% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 42,482 psi | 90% | 2339 fps | 99.4% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 42,163 psi | 89% | 2339 fps | 99.6% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,418 psi | 75% | 1476 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 41,118 psi | 87% | 2251 fps | 98.5% |
| IMR 4831 | <<locked>> | 94% | 41,989 psi | 89% | 2339 fps | 98.1% |
| IMR 4895 | <<locked>> | 82% | 42,583 psi | 90% | 2323 fps | 99.1% |
| Lovex S062 | <<locked>> | 82% | 40,944 psi | 87% | 2254 fps | 99.6% |
| Lovex S065 | <<locked>> | 88% | 40,306 psi | 86% | 2247 fps | 96.2% |
| Norma 203B | <<locked>> | 82% | 40,930 psi | 87% | 2287 fps | 98.8% |
| Norma URP | <<locked>> | 92% | 41,017 psi | 87% | 2336 fps | 97.7% |
| Ramshot Big Game | <<locked>> | 82% | 40,422 psi | 86% | 2300 fps | 98.6% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,897 psi | 76% | 1512 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 42,279 psi | 90% | 2283 fps | 95.9% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 40,524 psi | 86% | 2375 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 40,654 psi | 86% | 2356 fps | 97.5% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 41,002 psi | 87% | 2369 fps | 96.8% |
| Rottweil R 903 | <<locked>> | 86% | 41,002 psi | 87% | 2290 fps | 99.3% |
| Shooters World Long Rifle | <<locked>> | 88% | 40,306 psi | 86% | 2247 fps | 96.2% |
| Shooters World Precision | <<locked>> | 82% | 40,944 psi | 87% | 2254 fps | 99.6% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 42,177 psi | 89% | 2336 fps | 99% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 41,249 psi | 88% | 2192 fps | 100% |
| Somchem S355 | <<locked>> | 86% | 41,829 psi | 89% | 2293 fps | 99.2% |
| Somchem S365 | <<locked>> | 96% | 41,756 psi | 89% | 2388 fps | 99.9% |
| Vihtavuori N135 | <<locked>> | 82% | 42,395 psi | 90% | 2251 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 42,598 psi | 90% | 2277 fps | 99.9% |
| Vihtavuori N160 | <<locked>> | 90% | 40,350 psi | 86% | 2290 fps | 97.5% |
| Vihtavuori N540 | <<locked>> | 82% | 41,321 psi | 88% | 2251 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 42,279 psi | 90% | 2339 fps | 97.8% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 40,118 psi | 85% | 2369 fps | 98.3% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 40,422 psi | 86% | 2274 fps | 99.2% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 33,098 psi | 70% | 2297 fps | 97.9% |
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% | 39,653 psi | 84% | 2215 fps | 100% |
| Accurate 4064 | <<locked>> | 80% | 37,521 psi | 80% | 2208 fps | 100% |
| Accurate 4350 | <<locked>> | 86% | 33,373 psi | 71% | 2192 fps | 95.6% |
| ADI AR 2208 | <<locked>> | 80% | 36,753 psi | 78% | 2175 fps | 97.2% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 39,117 psi | 83% | 2329 fps | 97.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 36,274 psi | 77% | 2195 fps | 98.6% |
| Alliant Reloder-15 | <<locked>> | 80% | 39,015 psi | 83% | 2251 fps | 98% |
| Alliant Reloder-16 | <<locked>> | 86% | 34,026 psi | 72% | 2201 fps | 95.7% |
| Alliant Reloder-17 | 62.7 gr | 80% | 31,241 psi | 66% | 2165 fps | 96.5% |
| Alliant Reloder-23 | <<locked>> | 92% | 29,182 psi | 62% | 2116 fps | 95.3% |
| Alliant Reloder-26 | <<locked>> | 96% | 35,665 psi | 76% | 2323 fps | 95.4% |
| Bofors RP3 | <<locked>> | 80% | 35,752 psi | 76% | 2198 fps | 98.6% |
| Hodgdon H380 | <<locked>> | 80% | 36,738 psi | 78% | 2201 fps | 96.1% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 29,211 psi | 62% | 2067 fps | 95.7% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 39,523 psi | 84% | 2293 fps | 99.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,281 psi | 56% | 1312 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 38,580 psi | 82% | 2205 fps | 97.9% |
| IMR 4831 | <<locked>> | 86% | 32,489 psi | 69% | 2156 fps | 95.3% |
| IMR 4895 | <<locked>> | 80% | 39,943 psi | 85% | 2277 fps | 98.7% |
| Lovex S062 | <<locked>> | 80% | 38,566 psi | 82% | 2211 fps | 99.2% |
| Lovex S065 | <<locked>> | 86% | 38,029 psi | 81% | 2205 fps | 95.5% |
| Norma 203B | <<locked>> | 80% | 38,377 psi | 81% | 2241 fps | 98.3% |
| Norma URP | <<locked>> | 86% | 33,939 psi | 72% | 2195 fps | 95.6% |
| Ramshot Big Game | <<locked>> | 80% | 37,753 psi | 80% | 2251 fps | 98% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,629 psi | 56% | 1345 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 39,740 psi | 84% | 2234 fps | 95.1% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 33,257 psi | 71% | 2224 fps | 99.3% |
| ReloadSwiss RS 62 | 67.4 gr | 86% | 33,243 psi | 71% | 2208 fps | 95% |
| ReloadSwiss RS 70 | 71.7 gr | 90% | 38,363 psi | 81% | 2313 fps | 95.9% |
| Rottweil R 903 | <<locked>> | 80% | 33,649 psi | 71% | 2149 fps | 97.8% |
| Shooters World Long Rifle | <<locked>> | 86% | 38,029 psi | 81% | 2205 fps | 95.5% |
| Shooters World Precision | <<locked>> | 80% | 38,566 psi | 82% | 2211 fps | 99.2% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 34,577 psi | 73% | 2192 fps | 97.2% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 36,318 psi | 77% | 2110 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 34,650 psi | 74% | 2156 fps | 97.8% |
| Somchem S365 | <<locked>> | 80% | 25,121 psi | 53% | 2008 fps | 95.1% |
| Vihtavuori N135 | <<locked>> | 80% | 39,682 psi | 84% | 2205 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 32,837 psi | 70% | 2100 fps | 98.5% |
| Vihtavuori N160 | <<locked>> | 84% | 33,286 psi | 71% | 2149 fps | 95.2% |
| Vihtavuori N540 | <<locked>> | 80% | 38,812 psi | 82% | 2208 fps | 100% |
| Vihtavuori N550 | <<locked>> | 86% | 34,853 psi | 74% | 2198 fps | 95.6% |
| Vihtavuori N555 | <<locked>> | 92% | 31,053 psi | 66% | 2182 fps | 95.4% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 29,167 psi | 62% | 2034 fps | 95.7% |
| Winchester StaBALL HD | <<locked>> | 96% | 29,182 psi | 62% | 2182 fps | 95.6% |
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 44 powders for .375 Fl. Mag. N.E. loaded with the .375 | 300gr | Swift A-Frame. Alliant Reloder-26 delivers the highest muzzle velocity at 2,438 fps; across all powders the maximum-charge window runs from 1,476 fps to 2,438 fps. Alliant Reloder-23 gives the best case fill at 100 %, and 44 of the 44 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (325 MPa), the top charges use 70–90 %, leaving at least 10 % headroom. The 300.0 gr projectile in 0.375" calls for a 1:6.0 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. ReloadSwiss RS 70, Alliant Reloder-17, ReloadSwiss RS 62 rank at the top here: for .375 Fl. Mag. N.E. with the .375 | 300gr | Swift A-Frame 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.