Load Specifications
Bullet:.338 | 307gr | Hornady Sub-X
Bullet Manufacturer:Hornady
Bullet Weight:307 gr
Bullet Diameter:0.338"
Bullet Length:<<locked>>
Caliber:.338 Weatherby RPM load data
Case Length (l3):2.55"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:81.6 Grains of Water
Primer Size:Large Rifle Magnum (LRM)
Barrel Length:24"
Max. allowed Pressure:65,000 psi
Recommended Twist Rate:1:12.0
Load data in caliber .338 Weatherby RPM with .338 | 307gr | Hornady Sub-X bullet and 118 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 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 2015 | <<locked>> | 82% | 58,334 psi | 90% | 2142 fps | 100% |
| Accurate 2495 | <<locked>> | 86% | 57,841 psi | 89% | 2175 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 55,695 psi | 86% | 2205 fps | 99.4% |
| Accurate 3100ᴾ | <<locked>> | 100% | 48,124 psi | 74% | 2198 fps | 99.7% |
| Accurate 4064 | <<locked>> | 88% | 57,769 psi | 89% | 2218 fps | 100% |
| Accurate 4350 | <<locked>> | 96% | 58,146 psi | 89% | 2316 fps | 100% |
| Accurate MAGPROᴾ | <<locked>> | 100% | 49,501 psi | 76% | 2306 fps | 96.3% |
| ADI AR 2206H | <<locked>> | 84% | 57,348 psi | 88% | 2247 fps | 100% |
| ADI AR 2208 | <<locked>> | 90% | 58,247 psi | 90% | 2251 fps | 100% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 55,303 psi | 85% | 2313 fps | 99% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 49,559 psi | 76% | 2264 fps | 97% |
| ADI Benchmark 8208 | <<locked>> | 82% | 56,115 psi | 86% | 2201 fps | 100% |
| Alliant AR-Comp | <<locked>> | 82% | 57,943 psi | 89% | 2165 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 86% | 57,276 psi | 88% | 2359 fps | 100% |
| Alliant Power Pro Varmintᴾ | <<locked>> | 100% | 55,317 psi | 85% | 2313 fps | 99.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 90% | 58,813 psi | 90% | 2267 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 86% | 55,811 psi | 86% | 2251 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 98% | 58,581 psi | 90% | 2356 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 92% | 56,463 psi | 87% | 2343 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 54,491 psi | 84% | 2306 fps | 99% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 47,921 psi | 74% | 2267 fps | 98.3% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 45,382 psi | 70% | 2215 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 39,624 psi | 61% | 2159 fps | 99.2% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 51,227 psi | 79% | 2369 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 84% | 57,101 psi | 88% | 2270 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 44,034 psi | 68% | 2205 fps | 97.4% |
| Bofors RP3 | <<locked>> | 88% | 56,188 psi | 86% | 2247 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 47,921 psi | 74% | 2267 fps | 98.3% |
| Bofors RP7 | <<locked>> | 92% | 55,753 psi | 86% | 2241 fps | 99.6% |
| Hodgdon Benchmark | <<locked>> | 82% | 57,348 psi | 88% | 2178 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 82% | 55,753 psi | 86% | 2231 fps | 100% |
| Hodgdon H380 | <<locked>> | 88% | 56,565 psi | 87% | 2260 fps | 100% |
| Hodgdon H414 | <<locked>> | 94% | 56,594 psi | 87% | 2320 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 92% | 57,029 psi | 88% | 2290 fps | 99.4% |
| Hodgdon H4831ᴾ | <<locked>> | 100% | 53,127 psi | 82% | 2267 fps | 97.1% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 51,982 psi | 80% | 2254 fps | 96.9% |
| Hodgdon H4895 | <<locked>> | 84% | 57,986 psi | 89% | 2254 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 98% | 55,405 psi | 85% | 2254 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 86% | 57,957 psi | 89% | 2287 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 38,899 psi | 60% | 2178 fps | 96.5% |
| Hodgdon Superformance | <<locked>> | 94% | 56,840 psi | 87% | 2359 fps | 99.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,303 psi | 56% | 1329 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 55,419 psi | 85% | 2215 fps | 100% |
| IMR 3031 | <<locked>> | 84% | 58,653 psi | 90% | 2228 fps | 100% |
| IMR 4064 | <<locked>> | 88% | 57,783 psi | 89% | 2234 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 86% | 57,290 psi | 88% | 2231 fps | 99.8% |
| IMR 4350 | <<locked>> | 96% | 56,246 psi | 87% | 2267 fps | 99.6% |
| IMR 4451 Enduron | <<locked>> | 92% | 57,290 psi | 88% | 2257 fps | 99.8% |
| IMR 4831 | <<locked>> | 98% | 58,334 psi | 90% | 2306 fps | 100% |
| IMR 4895 | <<locked>> | 86% | 57,261 psi | 88% | 2270 fps | 100% |
| IMR 4955 Enduronᴾ | <<locked>> | 100% | 54,926 psi | 85% | 2257 fps | 97.6% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 47,050 psi | 72% | 2241 fps | 96.6% |
| IMR 8208 XBR | <<locked>> | 82% | 56,115 psi | 86% | 2201 fps | 100% |
| Lovex D073.6 | <<locked>> | 84% | 57,551 psi | 89% | 2224 fps | 100% |
| Lovex S060 | <<locked>> | 84% | 56,304 psi | 87% | 2182 fps | 100% |
| Lovex S062 | <<locked>> | 88% | 58,030 psi | 89% | 2231 fps | 100% |
| Lovex S065 | <<locked>> | 94% | 57,217 psi | 88% | 2254 fps | 100% |
| Lovex S070 | <<locked>> | 96% | 58,392 psi | 90% | 2290 fps | 99.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 40,045 psi | 62% | 2083 fps | 98.7% |
| Norma 201 | <<locked>> | 84% | 56,072 psi | 86% | 2198 fps | 100% |
| Norma 202 | <<locked>> | 84% | 56,782 psi | 87% | 2195 fps | 100% |
| Norma 203B | <<locked>> | 88% | 58,523 psi | 90% | 2277 fps | 100% |
| Norma 204 | <<locked>> | 96% | 56,942 psi | 88% | 2313 fps | 99.1% |
| Norma MRPᴾ | <<locked>> | 100% | 50,676 psi | 78% | 2333 fps | 99.6% |
| Norma URP | <<locked>> | 96% | 56,855 psi | 87% | 2306 fps | 100% |
| Ramshot Big Game | <<locked>> | 86% | 55,419 psi | 85% | 2264 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 47,108 psi | 72% | 2251 fps | 96.9% |
| Ramshot Hunter | <<locked>> | 96% | 55,419 psi | 85% | 2313 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 41,640 psi | 64% | 2156 fps | 97.4% |
| Ramshot TAC | <<locked>> | 82% | 55,956 psi | 86% | 2231 fps | 100% |
| Ramshot Wild Boar | <<locked>> | 82% | 56,144 psi | 86% | 2244 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,941 psi | 57% | 1362 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 56,666 psi | 87% | 2251 fps | 99.9% |
| ReloadSwiss RS 52 | <<locked>> | 84% | 56,579 psi | 87% | 2303 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 90% | 56,043 psi | 86% | 2333 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 96% | 57,580 psi | 89% | 2339 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 56,318 psi | 87% | 2369 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 38,261 psi | 59% | 2169 fps | 97.3% |
| Rottweil R 901 | <<locked>> | 82% | 56,913 psi | 88% | 2172 fps | 100% |
| Rottweil R 902 | <<locked>> | 86% | 56,565 psi | 87% | 2198 fps | 100% |
| Rottweil R 903 | <<locked>> | 90% | 56,086 psi | 86% | 2241 fps | 100% |
| Rottweil R 904ᴾ | <<locked>> | 100% | 57,217 psi | 88% | 2287 fps | 98.4% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 53,461 psi | 82% | 2293 fps | 99% |
| Rottweil R 907 | <<locked>> | 92% | 55,753 psi | 86% | 2241 fps | 99.6% |
| Shooters World Long Rifle | <<locked>> | 94% | 57,217 psi | 88% | 2254 fps | 100% |
| Shooters World Match Rifle | <<locked>> | 84% | 57,551 psi | 89% | 2224 fps | 100% |
| Shooters World Precision | <<locked>> | 88% | 58,030 psi | 89% | 2231 fps | 100% |
| Shooters World SW4350 | <<locked>> | 96% | 58,392 psi | 90% | 2290 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 90% | 57,464 psi | 88% | 2290 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 84% | 58,740 psi | 90% | 2260 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 84% | 55,593 psi | 86% | 2228 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 84% | 57,305 psi | 88% | 2139 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 90% | 57,798 psi | 89% | 2142 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 94% | 57,058 psi | 88% | 2218 fps | 99.8% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 52,968 psi | 81% | 2290 fps | 98.9% |
| Somchem S335 | <<locked>> | 84% | 56,666 psi | 87% | 2139 fps | 100% |
| Somchem S341 | <<locked>> | 84% | 58,117 psi | 89% | 2244 fps | 100% |
| Somchem S355 | <<locked>> | 90% | 56,130 psi | 86% | 2238 fps | 100% |
| Somchem S361 | <<locked>> | 98% | 55,376 psi | 85% | 2244 fps | 97.4% |
| Somchem S365 | <<locked>> | 98% | 55,448 psi | 85% | 2306 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 54,114 psi | 83% | 2274 fps | 99.5% |
| Vihtavuori N133 | <<locked>> | 84% | 57,754 psi | 89% | 2123 fps | 100% |
| Vihtavuori N135 | <<locked>> | 86% | 56,927 psi | 88% | 2159 fps | 100% |
| Vihtavuori N140 | <<locked>> | 86% | 57,130 psi | 88% | 2175 fps | 100% |
| Vihtavuori N150 | <<locked>> | 92% | 57,479 psi | 88% | 2215 fps | 100% |
| Vihtavuori N160 | <<locked>> | 94% | 55,564 psi | 85% | 2257 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 46,789 psi | 72% | 2172 fps | 98.3% |
| Vihtavuori N530 | <<locked>> | 82% | 56,492 psi | 87% | 2198 fps | 100% |
| Vihtavuori N540 | <<locked>> | 88% | 58,668 psi | 90% | 2218 fps | 100% |
| Vihtavuori N550 | <<locked>> | 96% | 57,885 psi | 89% | 2306 fps | 100% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 50,589 psi | 78% | 2274 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 51,387 psi | 79% | 2323 fps | 97.3% |
| Winchester 6.5 StaBALL | <<locked>> | 96% | 58,653 psi | 90% | 2274 fps | 100% |
| Winchester 748 | <<locked>> | 82% | 57,029 psi | 88% | 2241 fps | 100% |
| Winchester 760 | <<locked>> | 94% | 56,913 psi | 88% | 2323 fps | 99.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 40,567 psi | 62% | 2260 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 84% | 55,608 psi | 86% | 2234 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 50,633 psi | 78% | 2224 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 2015 | <<locked>> | 80% | 54,781 psi | 84% | 2106 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 47,892 psi | 74% | 2067 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 46,035 psi | 71% | 2077 fps | 98.2% |
| Accurate 3100 | <<locked>> | 84% | 28,224 psi | 43% | 1864 fps | 95.1% |
| Accurate 4064 | <<locked>> | 80% | 45,368 psi | 70% | 2077 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 33,910 psi | 52% | 1982 fps | 98.7% |
| Accurate MAGPRO | <<locked>> | 98% | 46,412 psi | 71% | 2260 fps | 95.5% |
| ADI AR 2206H | <<locked>> | 80% | 50,676 psi | 78% | 2169 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 43,163 psi | 66% | 2060 fps | 100% |
| ADI AR 2209 | <<locked>> | 88% | 37,898 psi | 58% | 2054 fps | 95.4% |
| ADI AR 2213 | <<locked>> | 96% | 43,598 psi | 67% | 2172 fps | 95.5% |
| ADI Benchmark 8208 | <<locked>> | 80% | 52,794 psi | 81% | 2162 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 54,215 psi | 83% | 2129 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 46,688 psi | 72% | 2224 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 37,913 psi | 58% | 2057 fps | 95.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 43,265 psi | 67% | 2077 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 46,282 psi | 71% | 2129 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 33,576 psi | 52% | 1988 fps | 98.8% |
| Alliant Reloder-17 | 50.2 gr | 80% | 37,521 psi | 58% | 2083 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 37,507 psi | 58% | 2051 fps | 95.5% |
| Alliant Reloder-22 | <<locked>> | 92% | 37,188 psi | 57% | 2090 fps | 95.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 24,584 psi | 38% | 1811 fps | 97% |
| Alliant Reloder-25 | <<locked>> | 90% | 29,356 psi | 45% | 1939 fps | 95.8% |
| Alliant Reloder-26 | <<locked>> | 82% | 27,514 psi | 42% | 1939 fps | 96% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 49,980 psi | 77% | 2185 fps | 100% |
| Bofors RP15 | <<locked>> | 94% | 36,709 psi | 56% | 2080 fps | 95.2% |
| Bofors RP3 | <<locked>> | 80% | 43,250 psi | 67% | 2087 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 37,188 psi | 57% | 2090 fps | 95.5% |
| Bofors RP7 | <<locked>> | 80% | 38,493 psi | 59% | 1991 fps | 96.8% |
| Hodgdon Benchmark | <<locked>> | 80% | 54,259 psi | 83% | 2142 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 52,170 psi | 80% | 2192 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 43,700 psi | 67% | 2096 fps | 99.7% |
| Hodgdon H414 | <<locked>> | 80% | 35,868 psi | 55% | 2018 fps | 96.8% |
| Hodgdon H4350 | <<locked>> | 80% | 39,044 psi | 60% | 2031 fps | 96.3% |
| Hodgdon H4831 | <<locked>> | 96% | 46,673 psi | 72% | 2178 fps | 95.7% |
| Hodgdon H4831 SC | <<locked>> | 96% | 45,672 psi | 70% | 2165 fps | 95.5% |
| Hodgdon H4895 | <<locked>> | 80% | 51,227 psi | 79% | 2175 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 31,082 psi | 48% | 1906 fps | 99.3% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 47,471 psi | 73% | 2165 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 36,564 psi | 56% | 2129 fps | 95.5% |
| Hodgdon Superformance | 53.1 gr | 80% | 34,838 psi | 54% | 2024 fps | 95.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,992 psi | 42% | 1181 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 48,892 psi | 75% | 2136 fps | 100% |
| IMR 3031 | <<locked>> | 80% | 51,735 psi | 80% | 2152 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 45,353 psi | 70% | 2083 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 47,659 psi | 73% | 2106 fps | 99% |
| IMR 4350 | <<locked>> | 80% | 34,258 psi | 53% | 1936 fps | 95.5% |
| IMR 4451 Enduron | <<locked>> | 80% | 39,885 psi | 61% | 2014 fps | 97.6% |
| IMR 4831 | <<locked>> | 80% | 32,851 psi | 51% | 1949 fps | 98.5% |
| IMR 4895 | <<locked>> | 80% | 47,442 psi | 73% | 2152 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 43,134 psi | 66% | 2093 fps | 95% |
| IMR 7828 SSC | <<locked>> | 98% | 44,121 psi | 68% | 2195 fps | 95.8% |
| IMR 8208 XBR | <<locked>> | 80% | 52,794 psi | 81% | 2162 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 50,676 psi | 78% | 2149 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 50,038 psi | 77% | 2110 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 45,484 psi | 70% | 2080 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 37,565 psi | 58% | 1982 fps | 98.3% |
| Lovex S070 | <<locked>> | 80% | 35,708 psi | 55% | 1965 fps | 96.9% |
| Lovex S071 | <<locked>> | 90% | 29,370 psi | 45% | 1890 fps | 95.6% |
| Norma 201 | <<locked>> | 80% | 49,777 psi | 77% | 2126 fps | 100% |
| Norma 202 | <<locked>> | 80% | 50,111 psi | 77% | 2119 fps | 100% |
| Norma 203B | <<locked>> | 80% | 45,629 psi | 70% | 2123 fps | 100% |
| Norma 204 | <<locked>> | 84% | 38,145 psi | 59% | 2044 fps | 95.4% |
| Norma MRP | <<locked>> | 86% | 31,821 psi | 49% | 2005 fps | 95% |
| Norma URP | <<locked>> | 80% | 34,055 psi | 52% | 1978 fps | 98.6% |
| Ramshot Big Game | <<locked>> | 80% | 45,426 psi | 70% | 2139 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 41,031 psi | 63% | 2152 fps | 95.2% |
| Ramshot Hunter | <<locked>> | 80% | 33,025 psi | 51% | 1972 fps | 96.8% |
| Ramshot Magnum | <<locked>> | 96% | 36,303 psi | 56% | 2060 fps | 95.7% |
| Ramshot TAC | <<locked>> | 80% | 52,431 psi | 81% | 2188 fps | 100% |
| Ramshot Wild Boar | <<locked>> | 80% | 52,591 psi | 81% | 2201 fps | 100% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,644 psi | 43% | 1214 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 43,874 psi | 67% | 2083 fps | 98.9% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 49,661 psi | 76% | 2221 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 39,914 psi | 61% | 2123 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 33,504 psi | 52% | 1998 fps | 98.4% |
| ReloadSwiss RS 70 | 51 gr | 80% | 32,967 psi | 51% | 2001 fps | 97.8% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 33,431 psi | 51% | 2064 fps | 95.2% |
| Rottweil R 901 | <<locked>> | 80% | 53,824 psi | 83% | 2136 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 47,398 psi | 73% | 2090 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 40,872 psi | 63% | 2047 fps | 100% |
| Rottweil R 904 | <<locked>> | 90% | 41,887 psi | 64% | 2080 fps | 95.4% |
| Rottweil R 905 | <<locked>> | 88% | 36,318 psi | 56% | 2034 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 80% | 38,493 psi | 59% | 1991 fps | 96.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 37,565 psi | 58% | 1982 fps | 98.3% |
| Shooters World Match Rifle | <<locked>> | 80% | 50,676 psi | 78% | 2149 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 45,484 psi | 70% | 2080 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 35,708 psi | 55% | 1965 fps | 96.9% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 41,829 psi | 64% | 2093 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 51,314 psi | 79% | 2175 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 49,182 psi | 76% | 2152 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 50,705 psi | 78% | 2067 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 42,627 psi | 66% | 1972 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 36,622 psi | 56% | 1936 fps | 96.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 35,984 psi | 55% | 2031 fps | 95.2% |
| Somchem S335 | <<locked>> | 80% | 50,430 psi | 78% | 2070 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 50,908 psi | 78% | 2162 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 41,408 psi | 64% | 2047 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 45,629 psi | 70% | 2116 fps | 95.4% |
| Somchem S365 | <<locked>> | 80% | 30,516 psi | 47% | 1946 fps | 99.9% |
| Somchem S385 | <<locked>> | 86% | 34,505 psi | 53% | 1978 fps | 95.6% |
| Vihtavuori N133 | <<locked>> | 80% | 51,184 psi | 79% | 2054 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 47,369 psi | 73% | 2057 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 47,616 psi | 73% | 2070 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 39,436 psi | 61% | 1991 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 35,360 psi | 54% | 1975 fps | 98.8% |
| Vihtavuori N165 | <<locked>> | 92% | 36,260 psi | 56% | 2005 fps | 95.7% |
| Vihtavuori N530 | <<locked>> | 80% | 52,982 psi | 82% | 2159 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 45,687 psi | 70% | 2070 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 34,766 psi | 53% | 1978 fps | 98.6% |
| Vihtavuori N555 | <<locked>> | 80% | 26,556 psi | 41% | 1867 fps | 97% |
| Vihtavuori N560 | <<locked>> | 96% | 45,005 psi | 69% | 2231 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 34,519 psi | 53% | 1955 fps | 99.8% |
| Winchester 748 | <<locked>> | 80% | 53,258 psi | 82% | 2201 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 36,042 psi | 55% | 2021 fps | 96.9% |
| Winchester StaBALL HD | <<locked>> | 80% | 21,625 psi | 33% | 1785 fps | 95.4% |
| Winchester StaBALL Match | <<locked>> | 80% | 48,834 psi | 75% | 2156 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 38,696 psi | 60% | 2051 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 118 powders for .338 Weatherby RPM loaded with the .338 | 307gr | Hornady Sub-X. Alliant Reloder-26 delivers the highest muzzle velocity at 2,369 fps; across all powders the maximum-charge window runs from 1,329 fps to 2,369 fps. Accurate 3100 gives the best case fill at 100 %, and 118 of the 118 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 56–90 %, leaving at least 10 % headroom. The 307.0 gr projectile in 0.338" calls for a 1:12.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate MAGPRO, ADI AR 2209 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, Hodgdon Superformance rank at the top here: for .338 Weatherby RPM with the .338 | 307gr | Hornady Sub-X 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.