Load Specifications
Bullet:.338 | 250gr | Barnes MRX BT
Bullet Manufacturer:Barnes
Bullet Weight:250 gr
Bullet Diameter:0.338"
Bullet Length:<<locked>>
Caliber:.338 RCM load data
Case Length (l3):2"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:71 Grains of Water
Primer Size:Large Rifle (LR)
Barrel Length:24"
Max. allowed Pressure:62,366 psi
Recommended Twist Rate:1:14.0
Load data in caliber .338 RCM with .338 | 250gr | Barnes MRX BT bullet and 104 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Power Pro 2000-MR, Hodgdon CFE223 and ReloadSwiss RS 52.
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>> | 90% | 55,274 psi | 89% | 2316 fps | 100% |
| Accurate 2200 | <<locked>> | 82% | 55,724 psi | 89% | 2405 fps | 99.6% |
| Accurate 2460 | <<locked>> | 86% | 53,635 psi | 86% | 2343 fps | 100% |
| Accurate 2495 | <<locked>> | 96% | 55,477 psi | 89% | 2369 fps | 100% |
| Accurate 2520 | <<locked>> | 90% | 53,214 psi | 85% | 2382 fps | 100% |
| Accurate 2700 | <<locked>> | 98% | 54,273 psi | 87% | 2329 fps | 96.2% |
| Accurate 4064 | <<locked>> | 98% | 55,027 psi | 88% | 2405 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 43,729 psi | 70% | 2329 fps | 98% |
| Accurate LT-30 | <<locked>> | 84% | 55,608 psi | 89% | 2270 fps | 100% |
| Accurate LT-32 | <<locked>> | 84% | 56,072 psi | 90% | 2293 fps | 100% |
| ADI AR 2206H | <<locked>> | 92% | 54,360 psi | 87% | 2402 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 98% | 55,201 psi | 89% | 2398 fps | 99.7% |
| ADI AR 2219 | <<locked>> | 84% | 55,941 psi | 90% | 2375 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 90% | 53,606 psi | 86% | 2362 fps | 100% |
| Alliant AR-Comp | <<locked>> | 90% | 53,301 psi | 85% | 2339 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 94% | 53,606 psi | 86% | 2500 fps | 99.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 98% | 54,302 psi | 87% | 2415 fps | 100% |
| Alliant Reloder-10x | <<locked>> | 86% | 55,245 psi | 89% | 2320 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 96% | 55,317 psi | 89% | 2438 fps | 99.8% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 44,498 psi | 71% | 2343 fps | 98.3% |
| Alliant Reloder-17ᴾ | <<locked>> | 100% | 51,256 psi | 82% | 2474 fps | 99.9% |
| Baschieri & Pellagri 106 | <<locked>> | 84% | 54,389 psi | 87% | 2274 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 92% | 53,882 psi | 86% | 2418 fps | 99.4% |
| Bofors RP3 | <<locked>> | 98% | 54,534 psi | 87% | 2428 fps | 100% |
| Bofors RP7ᴾ | <<locked>> | 100% | 52,228 psi | 84% | 2352 fps | 96.2% |
| Hodgdon Benchmark | <<locked>> | 90% | 55,956 psi | 90% | 2349 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 92% | 55,825 psi | 90% | 2434 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 88% | 53,998 psi | 87% | 2470 fps | 99.7% |
| Hodgdon H322 | <<locked>> | 86% | 54,578 psi | 88% | 2359 fps | 100% |
| Hodgdon H335 | <<locked>> | 86% | 55,506 psi | 89% | 2385 fps | 100% |
| Hodgdon H380 | <<locked>> | 98% | 56,159 psi | 90% | 2438 fps | 99.2% |
| Hodgdon H414ᴾ | <<locked>> | 100% | 47,877 psi | 77% | 2379 fps | 96.2% |
| Hodgdon H4895 | <<locked>> | 92% | 54,810 psi | 88% | 2411 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 40,393 psi | 65% | 2241 fps | 98.7% |
| Hodgdon LEVERevolution | <<locked>> | 94% | 53,258 psi | 85% | 2438 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,389 psi | 55% | 1394 fps | 100% |
| Hodgdon VARGET | <<locked>> | 92% | 52,866 psi | 85% | 2372 fps | 99.9% |
| IMR 3031 | <<locked>> | 92% | 54,099 psi | 87% | 2395 fps | 100% |
| IMR 4064 | <<locked>> | 96% | 54,723 psi | 88% | 2382 fps | 99.7% |
| IMR 4166 Enduron | <<locked>> | 94% | 55,695 psi | 89% | 2369 fps | 97.4% |
| IMR 4198 | <<locked>> | 86% | 55,927 psi | 90% | 2283 fps | 100% |
| IMR 4451 Enduronᴾ | <<locked>> | 100% | 54,389 psi | 87% | 2382 fps | 97.1% |
| IMR 4831ᴾ | <<locked>> | 100% | 42,192 psi | 68% | 2287 fps | 97.8% |
| IMR 4895 | <<locked>> | 94% | 53,055 psi | 85% | 2418 fps | 99.9% |
| IMR 8208 XBR | <<locked>> | 90% | 53,606 psi | 86% | 2362 fps | 100% |
| Lovex D073.5 | <<locked>> | 86% | 53,461 psi | 86% | 2352 fps | 100% |
| Lovex D073.6 | <<locked>> | 92% | 52,910 psi | 85% | 2379 fps | 100% |
| Lovex S060 | <<locked>> | 92% | 54,824 psi | 88% | 2343 fps | 99.9% |
| Lovex S062 | <<locked>> | 96% | 53,896 psi | 86% | 2379 fps | 100% |
| Lovex S065ᴾ | <<locked>> | 100% | 49,588 psi | 80% | 2329 fps | 97.7% |
| Lovex S070ᴾ | <<locked>> | 100% | 46,963 psi | 75% | 2313 fps | 96.1% |
| Norma 200 | <<locked>> | 82% | 54,882 psi | 88% | 2293 fps | 100% |
| Norma 201 | <<locked>> | 94% | 56,391 psi | 90% | 2395 fps | 100% |
| Norma 202 | <<locked>> | 92% | 53,359 psi | 86% | 2359 fps | 100% |
| Norma 203B | <<locked>> | 96% | 54,375 psi | 87% | 2425 fps | 99.9% |
| Norma URPᴾ | <<locked>> | 100% | 44,411 psi | 71% | 2333 fps | 98% |
| Ramshot Big Game | <<locked>> | 96% | 54,665 psi | 88% | 2448 fps | 99.8% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 43,671 psi | 70% | 2320 fps | 95.9% |
| Ramshot TAC | <<locked>> | 90% | 54,230 psi | 87% | 2382 fps | 98.5% |
| Ramshot Wild Boar | <<locked>> | 90% | 53,055 psi | 85% | 2395 fps | 99.8% |
| Ramshot X-Terminator | <<locked>> | 88% | 55,158 psi | 88% | 2369 fps | 99.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 34,809 psi | 56% | 1430 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 86% | 53,461 psi | 86% | 2349 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 96% | 53,519 psi | 86% | 2382 fps | 97.7% |
| ReloadSwiss RS 52 | <<locked>> | 94% | 55,114 psi | 88% | 2490 fps | 99.8% |
| ReloadSwiss RS 60ᴾ | <<locked>> | 100% | 54,839 psi | 88% | 2520 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 43,787 psi | 70% | 2349 fps | 97.7% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 45,208 psi | 72% | 2369 fps | 97.2% |
| Rottweil R 901 | <<locked>> | 90% | 53,853 psi | 86% | 2339 fps | 100% |
| Rottweil R 902 | <<locked>> | 94% | 53,301 psi | 85% | 2352 fps | 100% |
| Rottweil R 903ᴾ | <<locked>> | 100% | 54,070 psi | 87% | 2415 fps | 100% |
| Rottweil R 907ᴾ | <<locked>> | 100% | 52,228 psi | 84% | 2352 fps | 96.2% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 49,588 psi | 80% | 2329 fps | 97.7% |
| Shooters World Match Rifle | <<locked>> | 92% | 52,910 psi | 85% | 2379 fps | 100% |
| Shooters World Precision | <<locked>> | 96% | 53,896 psi | 86% | 2379 fps | 100% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 46,963 psi | 75% | 2313 fps | 96.1% |
| Shooters World Tactical Rifle | <<locked>> | 84% | 53,534 psi | 86% | 2326 fps | 100% |
| SNPE Vectan BA6 1/2 | <<locked>> | 82% | 56,028 psi | 90% | 2047 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 84% | 56,275 psi | 90% | 2388 fps | 100% |
| SNPE Vectan SP 11ᴾ | <<locked>> | 100% | 56,159 psi | 90% | 2474 fps | 99.9% |
| SNPE Vectan SP 3 | <<locked>> | 84% | 53,026 psi | 85% | 2300 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 92% | 55,825 psi | 90% | 2405 fps | 99.1% |
| SNPE Vectan SP 9 | <<locked>> | 94% | 56,101 psi | 90% | 2421 fps | 99.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 92% | 55,477 psi | 89% | 2306 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 98% | 54,708 psi | 88% | 2300 fps | 100% |
| SNPE Vectan Tubal 7000ᴾ | <<locked>> | 100% | 50,024 psi | 80% | 2290 fps | 96.4% |
| Somchem S321 | <<locked>> | 88% | 54,882 psi | 88% | 2398 fps | 100% |
| Somchem S335 | <<locked>> | 92% | 54,056 psi | 87% | 2303 fps | 100% |
| Somchem S341 | <<locked>> | 92% | 55,143 psi | 88% | 2395 fps | 99.8% |
| Somchem S355ᴾ | <<locked>> | 100% | 54,723 psi | 88% | 2415 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 39,436 psi | 63% | 2287 fps | 99.6% |
| Vihtavuori N130 | <<locked>> | 88% | 55,274 psi | 89% | 2277 fps | 100% |
| Vihtavuori N133 | <<locked>> | 92% | 55,419 psi | 89% | 2293 fps | 100% |
| Vihtavuori N135 | <<locked>> | 96% | 55,550 psi | 89% | 2356 fps | 100% |
| Vihtavuori N140 | <<locked>> | 94% | 53,838 psi | 86% | 2339 fps | 100% |
| Vihtavuori N150ᴾ | <<locked>> | 100% | 53,084 psi | 85% | 2359 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 46,717 psi | 75% | 2329 fps | 98.3% |
| Vihtavuori N530 | <<locked>> | 90% | 54,447 psi | 87% | 2365 fps | 100% |
| Vihtavuori N540 | <<locked>> | 96% | 55,492 psi | 89% | 2382 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 45,803 psi | 73% | 2336 fps | 98% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 47,993 psi | 77% | 2323 fps | 99.7% |
| Winchester 748 | <<locked>> | 90% | 53,243 psi | 85% | 2405 fps | 100% |
| Winchester 760ᴾ | <<locked>> | 100% | 48,196 psi | 77% | 2385 fps | 96.2% |
| Winchester StaBALL Match | <<locked>> | 94% | 55,869 psi | 90% | 2431 fps | 100% |
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% | 40,364 psi | 65% | 2126 fps | 100% |
| Accurate 2200 | <<locked>> | 80% | 52,330 psi | 84% | 2359 fps | 99.4% |
| Accurate 2460 | <<locked>> | 80% | 43,714 psi | 70% | 2215 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 32,358 psi | 52% | 2051 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 37,550 psi | 60% | 2162 fps | 99.7% |
| Accurate 2700 | <<locked>> | 96% | 50,720 psi | 81% | 2287 fps | 95.5% |
| Accurate 4064 | <<locked>> | 80% | 30,690 psi | 49% | 2037 fps | 99.4% |
| Accurate 4350 | <<locked>> | 92% | 33,098 psi | 53% | 2142 fps | 95.1% |
| Accurate LT-30 | <<locked>> | 80% | 49,226 psi | 79% | 2195 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 49,617 psi | 80% | 2215 fps | 100% |
| ADI AR 2206H | <<locked>> | 80% | 37,043 psi | 59% | 2139 fps | 97.6% |
| ADI AR 2208 | <<locked>> | 80% | 31,662 psi | 51% | 2014 fps | 95% |
| ADI AR 2219 | <<locked>> | 80% | 49,037 psi | 79% | 2293 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 80% | 39,117 psi | 63% | 2149 fps | 99% |
| Alliant AR-Comp | <<locked>> | 80% | 38,189 psi | 61% | 2149 fps | 100% |
| Alliant Power Pro 2000-MR | 44.4 gr | 80% | 33,504 psi | 54% | 2146 fps | 95.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 30,589 psi | 49% | 2031 fps | 96.6% |
| Alliant Reloder-10x | <<locked>> | 80% | 46,079 psi | 74% | 2208 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 32,982 psi | 53% | 2080 fps | 95.8% |
| Alliant Reloder-16 | <<locked>> | 92% | 34,795 psi | 56% | 2159 fps | 95.4% |
| Alliant Reloder-17 | <<locked>> | 84% | 30,197 psi | 48% | 2083 fps | 95.4% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 47,979 psi | 77% | 2195 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 35,969 psi | 58% | 2139 fps | 96.1% |
| Bofors RP3 | <<locked>> | 80% | 29,588 psi | 47% | 2024 fps | 96.4% |
| Bofors RP7 | <<locked>> | 98% | 49,095 psi | 79% | 2310 fps | 95.5% |
| Hodgdon Benchmark | <<locked>> | 80% | 41,350 psi | 66% | 2149 fps | 99.6% |
| Hodgdon BL-C2 | <<locked>> | 80% | 37,144 psi | 60% | 2165 fps | 99.1% |
| Hodgdon CFE223 | 45.4 gr | 80% | 40,886 psi | 66% | 2277 fps | 98.1% |
| Hodgdon H322 | <<locked>> | 80% | 44,846 psi | 72% | 2238 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 45,411 psi | 73% | 2257 fps | 100% |
| Hodgdon H380 | <<locked>> | 84% | 35,346 psi | 57% | 2123 fps | 95.1% |
| Hodgdon H414 | <<locked>> | 98% | 44,773 psi | 72% | 2329 fps | 95.4% |
| Hodgdon H4895 | <<locked>> | 80% | 37,318 psi | 60% | 2149 fps | 98.2% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 29,617 psi | 47% | 2024 fps | 95.3% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 33,373 psi | 54% | 2119 fps | 97.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,469 psi | 41% | 1243 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 36,100 psi | 58% | 2113 fps | 97.8% |
| IMR 3031 | <<locked>> | 80% | 36,230 psi | 58% | 2149 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 33,127 psi | 53% | 2041 fps | 95.9% |
| IMR 4166 Enduron | <<locked>> | 88% | 45,992 psi | 74% | 2234 fps | 95.4% |
| IMR 4198 | <<locked>> | 80% | 46,891 psi | 75% | 2175 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 94% | 45,223 psi | 73% | 2251 fps | 95.1% |
| IMR 4831 | <<locked>> | 94% | 34,679 psi | 56% | 2156 fps | 95.7% |
| IMR 4895 | <<locked>> | 80% | 33,736 psi | 54% | 2103 fps | 96.8% |
| IMR 8208 XBR | <<locked>> | 80% | 39,117 psi | 63% | 2149 fps | 99% |
| Lovex D073.5 | <<locked>> | 80% | 43,613 psi | 70% | 2221 fps | 99.9% |
| Lovex D073.6 | <<locked>> | 80% | 35,215 psi | 56% | 2119 fps | 99.5% |
| Lovex S060 | <<locked>> | 80% | 38,058 psi | 61% | 2093 fps | 97.8% |
| Lovex S062 | <<locked>> | 80% | 32,663 psi | 52% | 2047 fps | 97.7% |
| Lovex S065 | <<locked>> | 92% | 38,696 psi | 62% | 2159 fps | 95.1% |
| Lovex S070 | <<locked>> | 98% | 44,193 psi | 71% | 2270 fps | 95.4% |
| Norma 200 | <<locked>> | 80% | 51,605 psi | 83% | 2254 fps | 100% |
| Norma 201 | <<locked>> | 80% | 36,187 psi | 58% | 2100 fps | 98.5% |
| Norma 202 | <<locked>> | 80% | 36,492 psi | 59% | 2116 fps | 99.8% |
| Norma 203B | <<locked>> | 80% | 32,343 psi | 52% | 2070 fps | 96.2% |
| Norma URP | <<locked>> | 92% | 34,432 psi | 55% | 2152 fps | 95.2% |
| Ramshot Big Game | <<locked>> | 80% | 32,024 psi | 51% | 2080 fps | 95.7% |
| Ramshot Hunter | <<locked>> | 98% | 41,176 psi | 66% | 2277 fps | 95.2% |
| Ramshot TAC | <<locked>> | 80% | 39,030 psi | 63% | 2149 fps | 95.4% |
| Ramshot Wild Boar | <<locked>> | 80% | 38,072 psi | 61% | 2169 fps | 97.8% |
| Ramshot X-Terminator | <<locked>> | 80% | 42,380 psi | 68% | 2192 fps | 98.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 25,715 psi | 41% | 1273 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 44,237 psi | 71% | 2224 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 43,859 psi | 70% | 2241 fps | 95.7% |
| ReloadSwiss RS 52 | 43 gr | 80% | 34,055 psi | 55% | 2156 fps | 96.2% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 28,210 psi | 45% | 2044 fps | 97.2% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 35,868 psi | 58% | 2208 fps | 95.5% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 39,537 psi | 63% | 2267 fps | 95.5% |
| Rottweil R 901 | <<locked>> | 80% | 39,958 psi | 64% | 2142 fps | 99.9% |
| Rottweil R 902 | <<locked>> | 80% | 34,389 psi | 55% | 2060 fps | 98.1% |
| Rottweil R 903 | <<locked>> | 80% | 27,847 psi | 45% | 1978 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 98% | 49,095 psi | 79% | 2310 fps | 95.5% |
| Shooters World Long Rifle | <<locked>> | 92% | 38,696 psi | 62% | 2159 fps | 95.1% |
| Shooters World Match Rifle | <<locked>> | 80% | 35,215 psi | 56% | 2119 fps | 99.5% |
| Shooters World Precision | <<locked>> | 80% | 32,663 psi | 52% | 2047 fps | 97.7% |
| Shooters World SW4350 | <<locked>> | 98% | 44,193 psi | 71% | 2270 fps | 95.4% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 46,731 psi | 75% | 2238 fps | 99.7% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 53,359 psi | 86% | 2021 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 80% | 49,313 psi | 79% | 2303 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 31,343 psi | 50% | 2070 fps | 95.5% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 47,007 psi | 75% | 2224 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 36,854 psi | 59% | 2123 fps | 95.4% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 35,723 psi | 57% | 2116 fps | 97.2% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 38,232 psi | 61% | 2073 fps | 99.9% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 31,256 psi | 50% | 1965 fps | 99.6% |
| SNPE Vectan Tubal 7000 | <<locked>> | 98% | 46,543 psi | 75% | 2244 fps | 95.6% |
| Somchem S321 | <<locked>> | 80% | 41,829 psi | 67% | 2218 fps | 99.5% |
| Somchem S335 | <<locked>> | 80% | 37,449 psi | 60% | 2077 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 36,608 psi | 59% | 2123 fps | 97.3% |
| Somchem S355 | <<locked>> | 80% | 29,022 psi | 47% | 1988 fps | 95.5% |
| Somchem S365 | <<locked>> | 88% | 26,919 psi | 43% | 2014 fps | 95.7% |
| Vihtavuori N130 | <<locked>> | 80% | 43,482 psi | 70% | 2133 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 38,406 psi | 62% | 2073 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 33,504 psi | 54% | 2057 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 34,432 psi | 55% | 2064 fps | 99.8% |
| Vihtavuori N150 | <<locked>> | 80% | 27,528 psi | 44% | 1942 fps | 96.5% |
| Vihtavuori N160 | <<locked>> | 92% | 36,172 psi | 58% | 2152 fps | 95.7% |
| Vihtavuori N530 | <<locked>> | 80% | 39,044 psi | 63% | 2146 fps | 99% |
| Vihtavuori N540 | <<locked>> | 80% | 32,866 psi | 53% | 2051 fps | 99.3% |
| Vihtavuori N550 | <<locked>> | 92% | 35,128 psi | 56% | 2156 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 30,327 psi | 49% | 2008 fps | 95.6% |
| Winchester 748 | <<locked>> | 80% | 37,927 psi | 61% | 2182 fps | 99.4% |
| Winchester 760 | <<locked>> | 98% | 45,063 psi | 72% | 2336 fps | 95.4% |
| Winchester StaBALL Match | <<locked>> | 80% | 34,737 psi | 56% | 2113 fps | 97.6% |
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 114 powders for .338 RCM loaded with the .338 | 250gr | Barnes MRX BT. ReloadSwiss RS 60 delivers the highest muzzle velocity at 2,520 fps; across all powders the maximum-charge window runs from 1,394 fps to 2,520 fps. Accurate 3100 gives the best case fill at 100 %, and 114 of the 114 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (430 MPa), the top charges use 44–90 %, leaving at least 10 % headroom. The 250.0 gr projectile in 0.338" calls for a 1:14.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, Accurate 4350, Alliant Reloder-16 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 Power Pro 2000-MR, Hodgdon CFE223, ReloadSwiss RS 52 rank at the top here: for .338 RCM with the .338 | 250gr | Barnes MRX BT they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Accurate 3100, Alliant Reloder-26, IMR 4350 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.