Load Specifications
Bullet Manufacturer:Lapua
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:1:13.5
Load data in caliber .338 RCM with .338 | 250gr | Lapua Lock Base bullet and 106 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, ReloadSwiss RS 52 and ReloadSwiss RS 60.
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>> | 88% | 53,838 psi | 86% | 2297 fps | 100% |
| Accurate 2460 | <<locked>> | 86% | 55,941 psi | 90% | 2365 fps | 100% |
| Accurate 2495 | <<locked>> | 94% | 54,389 psi | 87% | 2352 fps | 100% |
| Accurate 2520 | <<locked>> | 88% | 53,751 psi | 86% | 2375 fps | 100% |
| Accurate 2700 | <<locked>> | 94% | 55,390 psi | 89% | 2352 fps | 96.5% |
| Accurate 4064 | <<locked>> | 96% | 54,331 psi | 87% | 2395 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 46,224 psi | 74% | 2365 fps | 98.5% |
| Accurate LT-30 | <<locked>> | 82% | 53,766 psi | 86% | 2251 fps | 100% |
| Accurate LT-32 | <<locked>> | 82% | 54,172 psi | 87% | 2270 fps | 100% |
| ADI AR 2206H | <<locked>> | 92% | 55,970 psi | 90% | 2425 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 96% | 53,693 psi | 86% | 2379 fps | 99.6% |
| ADI AR 2219 | <<locked>> | 82% | 54,143 psi | 87% | 2356 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 90% | 55,492 psi | 89% | 2385 fps | 100% |
| Alliant AR-Comp | <<locked>> | 90% | 55,187 psi | 88% | 2359 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 84% | 53,563 psi | 86% | 2428 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 94% | 55,303 psi | 89% | 2526 fps | 99.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 98% | 56,318 psi | 90% | 2438 fps | 100% |
| Alliant Reloder-10x | <<locked>> | 84% | 53,780 psi | 86% | 2300 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 94% | 53,693 psi | 86% | 2415 fps | 99.7% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 46,108 psi | 74% | 2369 fps | 98.7% |
| Alliant Reloder-17ᴾ | <<locked>> | 100% | 52,968 psi | 85% | 2497 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 32,474 psi | 52% | 2142 fps | 96.3% |
| Baschieri & Pellagri 106 | <<locked>> | 84% | 56,014 psi | 90% | 2290 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 92% | 55,651 psi | 89% | 2438 fps | 99.6% |
| Bofors RP3 | <<locked>> | 96% | 52,997 psi | 85% | 2408 fps | 100% |
| Bofors RP7ᴾ | <<locked>> | 100% | 54,027 psi | 87% | 2379 fps | 96.6% |
| Hodgdon Benchmark | <<locked>> | 88% | 54,230 psi | 87% | 2329 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 90% | 54,186 psi | 87% | 2415 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 88% | 55,970 psi | 90% | 2497 fps | 99.9% |
| Hodgdon H322 | <<locked>> | 86% | 56,173 psi | 90% | 2379 fps | 100% |
| Hodgdon H335 | <<locked>> | 84% | 53,824 psi | 86% | 2365 fps | 100% |
| Hodgdon H380 | <<locked>> | 96% | 54,781 psi | 88% | 2421 fps | 99.1% |
| Hodgdon H414ᴾ | <<locked>> | 100% | 49,617 psi | 80% | 2405 fps | 96.6% |
| Hodgdon H4350ᴾ | <<locked>> | 100% | 54,549 psi | 87% | 2421 fps | 96.1% |
| Hodgdon H4895 | <<locked>> | 92% | 56,434 psi | 90% | 2431 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 42,119 psi | 68% | 2267 fps | 99% |
| Hodgdon LEVERevolution | <<locked>> | 94% | 55,158 psi | 88% | 2461 fps | 100% |
| Hodgdon Superformanceᴾ | <<locked>> | 100% | 51,010 psi | 82% | 2434 fps | 96% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,708 psi | 56% | 1401 fps | 100% |
| Hodgdon VARGET | <<locked>> | 92% | 54,636 psi | 88% | 2395 fps | 100% |
| IMR 3031 | <<locked>> | 92% | 55,927 psi | 90% | 2415 fps | 100% |
| IMR 4064 | <<locked>> | 94% | 53,026 psi | 85% | 2362 fps | 99.6% |
| IMR 4166 Enduron | <<locked>> | 92% | 53,838 psi | 86% | 2346 fps | 97.2% |
| IMR 4198 | <<locked>> | 84% | 54,418 psi | 87% | 2264 fps | 100% |
| IMR 4451 Enduronᴾ | <<locked>> | 100% | 56,014 psi | 90% | 2405 fps | 97.5% |
| IMR 4831ᴾ | <<locked>> | 100% | 44,092 psi | 71% | 2316 fps | 98.2% |
| IMR 4895 | <<locked>> | 94% | 55,027 psi | 88% | 2444 fps | 99.9% |
| IMR 8208 XBR | <<locked>> | 90% | 55,492 psi | 89% | 2385 fps | 100% |
| Lovex D073.5 | <<locked>> | 86% | 55,738 psi | 89% | 2375 fps | 100% |
| Lovex D073.6 | <<locked>> | 92% | 55,129 psi | 88% | 2402 fps | 100% |
| Lovex S060 | <<locked>> | 92% | 56,231 psi | 90% | 2362 fps | 99.9% |
| Lovex S062 | <<locked>> | 96% | 55,927 psi | 90% | 2402 fps | 100% |
| Lovex S065ᴾ | <<locked>> | 100% | 51,459 psi | 83% | 2356 fps | 98.1% |
| Lovex S070ᴾ | <<locked>> | 100% | 48,863 psi | 78% | 2339 fps | 96.6% |
| Norma 201 | <<locked>> | 92% | 54,868 psi | 88% | 2379 fps | 100% |
| Norma 202 | <<locked>> | 92% | 55,332 psi | 89% | 2382 fps | 100% |
| Norma 203B | <<locked>> | 96% | 56,376 psi | 90% | 2451 fps | 100% |
| Norma URPᴾ | <<locked>> | 100% | 46,195 psi | 74% | 2359 fps | 98.4% |
| Ramshot Big Game | <<locked>> | 94% | 52,881 psi | 85% | 2428 fps | 99.8% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 45,556 psi | 73% | 2349 fps | 96.5% |
| Ramshot TAC | <<locked>> | 90% | 55,912 psi | 90% | 2405 fps | 98.8% |
| Ramshot Wild Boar | <<locked>> | 90% | 54,882 psi | 88% | 2418 fps | 99.9% |
| Ramshot X-Terminator | <<locked>> | 86% | 53,214 psi | 85% | 2346 fps | 99.7% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,201 psi | 56% | 1437 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 86% | 55,332 psi | 89% | 2372 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 96% | 55,303 psi | 89% | 2405 fps | 98% |
| ReloadSwiss RS 52 | <<locked>> | 92% | 53,417 psi | 86% | 2470 fps | 99.7% |
| ReloadSwiss RS 60 | <<locked>> | 98% | 52,924 psi | 85% | 2500 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 45,905 psi | 74% | 2382 fps | 98.2% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 47,021 psi | 75% | 2402 fps | 97.7% |
| Rottweil R 901 | <<locked>> | 90% | 55,941 psi | 90% | 2359 fps | 100% |
| Rottweil R 902 | <<locked>> | 94% | 55,129 psi | 88% | 2372 fps | 100% |
| Rottweil R 903ᴾ | <<locked>> | 100% | 56,289 psi | 90% | 2441 fps | 100% |
| Rottweil R 907ᴾ | <<locked>> | 100% | 54,027 psi | 87% | 2379 fps | 96.6% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 51,459 psi | 83% | 2356 fps | 98.1% |
| Shooters World Match Rifle | <<locked>> | 92% | 55,129 psi | 88% | 2402 fps | 100% |
| Shooters World Precision | <<locked>> | 96% | 55,927 psi | 90% | 2402 fps | 100% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 48,863 psi | 78% | 2339 fps | 96.6% |
| Shooters World Tactical Rifle | <<locked>> | 84% | 55,114 psi | 88% | 2346 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 82% | 54,273 psi | 87% | 2365 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 98% | 54,621 psi | 88% | 2454 fps | 99.9% |
| SNPE Vectan SP 3 | <<locked>> | 84% | 54,737 psi | 88% | 2316 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 90% | 53,780 psi | 86% | 2379 fps | 98.9% |
| SNPE Vectan SP 9 | <<locked>> | 92% | 54,360 psi | 87% | 2402 fps | 99.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 90% | 53,737 psi | 86% | 2287 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 96% | 53,200 psi | 85% | 2283 fps | 100% |
| SNPE Vectan Tubal 7000ᴾ | <<locked>> | 100% | 51,967 psi | 83% | 2316 fps | 96.8% |
| Somchem S321 | <<locked>> | 86% | 53,026 psi | 85% | 2375 fps | 100% |
| Somchem S335 | <<locked>> | 92% | 55,999 psi | 90% | 2326 fps | 100% |
| Somchem S341 | <<locked>> | 90% | 53,359 psi | 86% | 2375 fps | 99.8% |
| Somchem S355 | <<locked>> | 98% | 53,476 psi | 86% | 2398 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 41,162 psi | 66% | 2316 fps | 99.8% |
| Vihtavuori N130 | <<locked>> | 86% | 53,664 psi | 86% | 2257 fps | 100% |
| Vihtavuori N133 | <<locked>> | 90% | 53,708 psi | 86% | 2274 fps | 100% |
| Vihtavuori N135 | <<locked>> | 94% | 54,302 psi | 87% | 2343 fps | 100% |
| Vihtavuori N140 | <<locked>> | 94% | 55,767 psi | 89% | 2362 fps | 100% |
| Vihtavuori N150ᴾ | <<locked>> | 100% | 54,969 psi | 88% | 2382 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 48,791 psi | 78% | 2359 fps | 98.7% |
| Vihtavuori N530 | <<locked>> | 90% | 56,043 psi | 90% | 2385 fps | 100% |
| Vihtavuori N540 | <<locked>> | 94% | 53,795 psi | 86% | 2362 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 47,587 psi | 76% | 2362 fps | 98.4% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 34,243 psi | 55% | 2205 fps | 96.3% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 49,777 psi | 80% | 2346 fps | 99.8% |
| Winchester 748 | <<locked>> | 90% | 55,187 psi | 88% | 2425 fps | 100% |
| Winchester 760ᴾ | <<locked>> | 100% | 49,951 psi | 80% | 2411 fps | 96.7% |
| Winchester StaBALL Match | <<locked>> | 92% | 54,070 psi | 87% | 2411 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% | 42,206 psi | 68% | 2149 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 45,658 psi | 73% | 2238 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 34,679 psi | 56% | 2083 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 40,843 psi | 65% | 2201 fps | 99.9% |
| Accurate 2700 | <<locked>> | 90% | 48,718 psi | 78% | 2264 fps | 95.2% |
| Accurate 4064 | <<locked>> | 80% | 32,779 psi | 53% | 2073 fps | 99.7% |
| Accurate 4350 | <<locked>> | 90% | 32,721 psi | 52% | 2129 fps | 95% |
| Accurate LT-30 | <<locked>> | 80% | 50,662 psi | 81% | 2211 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 51,039 psi | 82% | 2234 fps | 100% |
| ADI AR 2206H | <<locked>> | 80% | 38,624 psi | 62% | 2165 fps | 98% |
| ADI AR 2208 | <<locked>> | 80% | 33,069 psi | 53% | 2044 fps | 95.6% |
| ADI AR 2219 | <<locked>> | 80% | 50,676 psi | 81% | 2313 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 80% | 40,654 psi | 65% | 2175 fps | 99.2% |
| Alliant AR-Comp | <<locked>> | 80% | 40,001 psi | 64% | 2172 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 47,079 psi | 75% | 2339 fps | 99.7% |
| Alliant Power Pro 2000-MR | 44.9 gr | 80% | 34,867 psi | 56% | 2175 fps | 95.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 31,981 psi | 51% | 2057 fps | 97.2% |
| Alliant Reloder-10x | <<locked>> | 80% | 47,645 psi | 76% | 2224 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 34,563 psi | 55% | 2106 fps | 96.4% |
| Alliant Reloder-16 | <<locked>> | 90% | 34,272 psi | 55% | 2146 fps | 95.3% |
| Alliant Reloder-17 | <<locked>> | 82% | 29,602 psi | 47% | 2067 fps | 95.2% |
| Alliant Reloder-23 | <<locked>> | 98% | 30,690 psi | 49% | 2100 fps | 95.5% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 49,298 psi | 79% | 2211 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 37,405 psi | 60% | 2162 fps | 96.6% |
| Bofors RP3 | <<locked>> | 80% | 31,343 psi | 50% | 2060 fps | 97.1% |
| Bofors RP7 | <<locked>> | 96% | 47,718 psi | 77% | 2290 fps | 95.3% |
| Hodgdon Benchmark | <<locked>> | 80% | 42,801 psi | 69% | 2169 fps | 99.7% |
| Hodgdon BL-C2 | <<locked>> | 80% | 38,812 psi | 62% | 2192 fps | 99.4% |
| Hodgdon CFE223 | <<locked>> | 80% | 42,438 psi | 68% | 2300 fps | 98.4% |
| Hodgdon H322 | <<locked>> | 80% | 46,470 psi | 75% | 2257 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 47,007 psi | 75% | 2277 fps | 100% |
| Hodgdon H380 | <<locked>> | 84% | 36,985 psi | 59% | 2149 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 96% | 43,787 psi | 70% | 2316 fps | 95.2% |
| Hodgdon H4350 | <<locked>> | 98% | 51,430 psi | 82% | 2379 fps | 95.4% |
| Hodgdon H4895 | <<locked>> | 80% | 38,928 psi | 62% | 2175 fps | 98.6% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 29,254 psi | 47% | 2011 fps | 95.2% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 34,824 psi | 56% | 2146 fps | 98.1% |
| Hodgdon Superformance | <<locked>> | 98% | 47,456 psi | 76% | 2382 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,904 psi | 42% | 1250 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 37,550 psi | 60% | 2136 fps | 98.2% |
| IMR 3031 | <<locked>> | 80% | 37,985 psi | 61% | 2175 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 34,606 psi | 55% | 2070 fps | 96.5% |
| IMR 4166 Enduron | <<locked>> | 86% | 44,715 psi | 72% | 2215 fps | 95.2% |
| IMR 4198 | <<locked>> | 80% | 48,443 psi | 78% | 2195 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 92% | 44,222 psi | 71% | 2238 fps | 95% |
| IMR 4831 | <<locked>> | 92% | 34,098 psi | 55% | 2139 fps | 95.5% |
| IMR 4895 | <<locked>> | 80% | 35,360 psi | 57% | 2133 fps | 97.3% |
| IMR 8208 XBR | <<locked>> | 80% | 40,654 psi | 65% | 2175 fps | 99.2% |
| Lovex D073.5 | <<locked>> | 80% | 45,527 psi | 73% | 2244 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 37,043 psi | 59% | 2149 fps | 99.7% |
| Lovex S060 | <<locked>> | 80% | 39,494 psi | 63% | 2119 fps | 98.2% |
| Lovex S062 | <<locked>> | 80% | 34,345 psi | 55% | 2077 fps | 98.2% |
| Lovex S065 | <<locked>> | 90% | 38,189 psi | 61% | 2146 fps | 95% |
| Lovex S070 | <<locked>> | 96% | 43,149 psi | 69% | 2251 fps | 95.2% |
| Norma 201 | <<locked>> | 80% | 37,985 psi | 61% | 2129 fps | 98.9% |
| Norma 202 | <<locked>> | 80% | 37,913 psi | 61% | 2139 fps | 99.9% |
| Norma 203B | <<locked>> | 80% | 33,953 psi | 54% | 2100 fps | 96.8% |
| Norma URP | <<locked>> | 90% | 33,794 psi | 54% | 2136 fps | 95.1% |
| Ramshot Big Game | <<locked>> | 80% | 33,460 psi | 54% | 2106 fps | 96.3% |
| Ramshot Hunter | <<locked>> | 96% | 40,103 psi | 64% | 2257 fps | 95% |
| Ramshot TAC | <<locked>> | 80% | 40,466 psi | 65% | 2175 fps | 95.9% |
| Ramshot Wild Boar | <<locked>> | 80% | 39,610 psi | 64% | 2192 fps | 98.2% |
| Ramshot X-Terminator | <<locked>> | 80% | 44,092 psi | 71% | 2218 fps | 98.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,194 psi | 42% | 1283 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 45,803 psi | 73% | 2247 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 42,786 psi | 69% | 2224 fps | 95.5% |
| ReloadSwiss RS 52 | 43.5 gr | 80% | 35,621 psi | 57% | 2185 fps | 96.8% |
| ReloadSwiss RS 60 | 44.2 gr | 80% | 29,573 psi | 47% | 2077 fps | 97.9% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 35,244 psi | 57% | 2195 fps | 95.3% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 38,522 psi | 62% | 2247 fps | 95.2% |
| Rottweil R 901 | <<locked>> | 80% | 41,742 psi | 67% | 2165 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 36,129 psi | 58% | 2090 fps | 98.5% |
| Rottweil R 903 | <<locked>> | 80% | 29,544 psi | 47% | 2011 fps | 96.1% |
| Rottweil R 907 | <<locked>> | 96% | 47,718 psi | 77% | 2290 fps | 95.3% |
| Shooters World Long Rifle | <<locked>> | 90% | 38,189 psi | 61% | 2146 fps | 95% |
| Shooters World Match Rifle | <<locked>> | 80% | 37,043 psi | 59% | 2149 fps | 99.7% |
| Shooters World Precision | <<locked>> | 80% | 34,345 psi | 55% | 2077 fps | 98.2% |
| Shooters World SW4350 | <<locked>> | 96% | 43,149 psi | 69% | 2251 fps | 95.2% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 48,254 psi | 77% | 2260 fps | 99.8% |
| SNPE Vectan SP 10 | <<locked>> | 80% | 50,966 psi | 82% | 2323 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 30,690 psi | 49% | 2051 fps | 95.3% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 48,356 psi | 78% | 2241 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 38,508 psi | 62% | 2149 fps | 96% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 37,217 psi | 60% | 2139 fps | 97.6% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 39,552 psi | 63% | 2093 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 32,518 psi | 52% | 1985 fps | 99.8% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 45,440 psi | 73% | 2231 fps | 95.5% |
| Somchem S321 | <<locked>> | 80% | 43,468 psi | 70% | 2241 fps | 99.7% |
| Somchem S335 | <<locked>> | 80% | 39,088 psi | 63% | 2100 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 38,072 psi | 61% | 2149 fps | 97.8% |
| Somchem S355 | <<locked>> | 80% | 30,647 psi | 49% | 2021 fps | 96.2% |
| Somchem S365 | <<locked>> | 86% | 26,571 psi | 43% | 2001 fps | 95.6% |
| Vihtavuori N130 | <<locked>> | 80% | 44,860 psi | 72% | 2149 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 39,682 psi | 64% | 2093 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 35,041 psi | 56% | 2080 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 36,013 psi | 58% | 2087 fps | 99.9% |
| Vihtavuori N150 | <<locked>> | 80% | 29,066 psi | 47% | 1972 fps | 97.1% |
| Vihtavuori N160 | <<locked>> | 90% | 35,476 psi | 57% | 2139 fps | 95.6% |
| Vihtavuori N530 | <<locked>> | 80% | 40,611 psi | 65% | 2172 fps | 99.3% |
| Vihtavuori N540 | <<locked>> | 80% | 34,389 psi | 55% | 2077 fps | 99.6% |
| Vihtavuori N550 | <<locked>> | 90% | 34,505 psi | 55% | 2139 fps | 95.1% |
| Vihtavuori N555 | <<locked>> | 98% | 32,242 psi | 52% | 2162 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 29,689 psi | 48% | 1991 fps | 95.4% |
| Winchester 748 | <<locked>> | 80% | 39,552 psi | 63% | 2208 fps | 99.6% |
| Winchester 760 | <<locked>> | 96% | 43,787 psi | 70% | 2316 fps | 95.2% |
| Winchester StaBALL Match | <<locked>> | 80% | 36,303 psi | 58% | 2142 fps | 98% |
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 106 powders for .338 RCM loaded with the .338 | 250gr | Lapua Lock Base. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 2,526 fps; across all powders the maximum-charge window runs from 1,401 fps to 2,526 fps. Accurate 4350 gives the best case fill at 100 %, and 106 of the 106 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (430 MPa), the top charges use 52–90 %, leaving at least 10 % headroom. The 250.0 gr projectile in 0.338" calls for a 1:13.5 twist; slower twists will usually not stabilise this weight. Accurate 4350, Alliant Reloder-16, Alliant Reloder-17 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, ReloadSwiss RS 52, ReloadSwiss RS 60 rank at the top here: for .338 RCM with the .338 | 250gr | Lapua Lock Base 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.