Load Specifications
Load data in caliber 8.5 x 55 Blaser with .338 | 250gr | Speer Grand Slam bullet and 99 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 Superformance 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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You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 23.62"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 84% | 55,071 psi | 88% | 2365 fps | 100% |
| Accurate 2495 | <<locked>> | 88% | 53,432 psi | 86% | 2388 fps | 100% |
| Accurate 2520 | <<locked>> | 84% | 55,071 psi | 88% | 2448 fps | 100% |
| Accurate 2700 | <<locked>> | 90% | 56,028 psi | 90% | 2438 fps | 97.9% |
| Accurate 3100ᴾ | <<locked>> | 100% | 40,205 psi | 64% | 2306 fps | 96.6% |
| Accurate 4064 | <<locked>> | 90% | 53,403 psi | 86% | 2431 fps | 100% |
| Accurate 4350 | <<locked>> | 98% | 52,852 psi | 85% | 2513 fps | 99.8% |
| ADI AR 2206H | <<locked>> | 86% | 54,070 psi | 87% | 2461 fps | 100% |
| ADI AR 2208 | <<locked>> | 92% | 54,882 psi | 88% | 2461 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 84% | 52,997 psi | 85% | 2415 fps | 100% |
| Alliant AR-Comp | <<locked>> | 84% | 53,722 psi | 86% | 2388 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 88% | 53,200 psi | 85% | 2566 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 92% | 54,723 psi | 88% | 2477 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 90% | 55,317 psi | 89% | 2500 fps | 100% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 54,157 psi | 87% | 2559 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 96% | 55,274 psi | 89% | 2592 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 38,798 psi | 62% | 2339 fps | 99.3% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 42,902 psi | 69% | 2474 fps | 98.6% |
| Baschieri & Pellagri 107 | <<locked>> | 86% | 53,534 psi | 86% | 2477 fps | 99.9% |
| Bofors RP3 | <<locked>> | 92% | 55,434 psi | 89% | 2493 fps | 100% |
| Bofors RP7 | <<locked>> | 96% | 55,390 psi | 89% | 2470 fps | 98.1% |
| Hodgdon Benchmark | <<locked>> | 84% | 54,694 psi | 88% | 2398 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 86% | 55,651 psi | 89% | 2487 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 82% | 54,128 psi | 87% | 2533 fps | 100% |
| Hodgdon H380 | <<locked>> | 92% | 56,391 psi | 90% | 2510 fps | 99.8% |
| Hodgdon H414 | <<locked>> | 98% | 55,593 psi | 89% | 2556 fps | 98.7% |
| Hodgdon H4350 | <<locked>> | 94% | 53,040 psi | 85% | 2474 fps | 97.1% |
| Hodgdon H4895 | <<locked>> | 86% | 54,578 psi | 88% | 2470 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 50,444 psi | 81% | 2448 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 88% | 53,635 psi | 86% | 2500 fps | 100% |
| Hodgdon Superformance | <<locked>> | 98% | 56,318 psi | 90% | 2592 fps | 98.4% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,607 psi | 57% | 1473 fps | 100% |
| Hodgdon VARGET | <<locked>> | 88% | 55,608 psi | 89% | 2470 fps | 100% |
| IMR 3031 | <<locked>> | 86% | 54,578 psi | 88% | 2451 fps | 100% |
| IMR 4064 | <<locked>> | 90% | 54,462 psi | 87% | 2444 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 88% | 54,360 psi | 87% | 2428 fps | 98.3% |
| IMR 4350ᴾ | <<locked>> | 100% | 55,651 psi | 89% | 2497 fps | 98.1% |
| IMR 4451 Enduron | <<locked>> | 94% | 54,027 psi | 87% | 2454 fps | 98.2% |
| IMR 4831ᴾ | <<locked>> | 100% | 53,301 psi | 85% | 2503 fps | 99.8% |
| IMR 4895 | <<locked>> | 88% | 53,403 psi | 86% | 2480 fps | 100% |
| IMR 8208 XBR | <<locked>> | 84% | 52,997 psi | 85% | 2415 fps | 100% |
| Lovex D073.6 | <<locked>> | 86% | 53,635 psi | 86% | 2441 fps | 100% |
| Lovex S060 | <<locked>> | 86% | 53,592 psi | 86% | 2395 fps | 100% |
| Lovex S062 | <<locked>> | 90% | 54,172 psi | 87% | 2441 fps | 100% |
| Lovex S065 | <<locked>> | 96% | 53,214 psi | 85% | 2448 fps | 99.1% |
| Lovex S070 | <<locked>> | 98% | 54,070 psi | 87% | 2480 fps | 98.5% |
| Norma 201 | <<locked>> | 88% | 56,072 psi | 90% | 2454 fps | 100% |
| Norma 202 | <<locked>> | 86% | 53,287 psi | 85% | 2411 fps | 100% |
| Norma 203B | <<locked>> | 90% | 54,549 psi | 87% | 2487 fps | 100% |
| Norma 204ᴾ | <<locked>> | 100% | 56,202 psi | 90% | 2539 fps | 97.1% |
| Norma MRPᴾ | <<locked>> | 100% | 43,134 psi | 69% | 2438 fps | 96% |
| Norma URPᴾ | <<locked>> | 100% | 55,288 psi | 89% | 2543 fps | 99.9% |
| Ramshot Big Game | <<locked>> | 90% | 55,187 psi | 88% | 2516 fps | 100% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 54,085 psi | 87% | 2546 fps | 99.1% |
| Ramshot TAC | <<locked>> | 84% | 53,156 psi | 85% | 2438 fps | 99.2% |
| Ramshot Wild Boar | <<locked>> | 86% | 56,289 psi | 90% | 2497 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 82% | 53,751 psi | 86% | 2418 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,100 psi | 58% | 1509 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 82% | 55,927 psi | 90% | 2438 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 53,272 psi | 85% | 2448 fps | 98.7% |
| ReloadSwiss RS 52 | <<locked>> | 88% | 56,057 psi | 90% | 2559 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 94% | 55,071 psi | 88% | 2589 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 56,130 psi | 90% | 2582 fps | 99.9% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 55,680 psi | 89% | 2605 fps | 99.8% |
| Rottweil R 901 | <<locked>> | 84% | 53,809 psi | 86% | 2392 fps | 100% |
| Rottweil R 902 | <<locked>> | 88% | 53,142 psi | 85% | 2408 fps | 100% |
| Rottweil R 903 | <<locked>> | 94% | 55,317 psi | 89% | 2487 fps | 100% |
| Rottweil R 907 | <<locked>> | 96% | 55,390 psi | 89% | 2470 fps | 98.1% |
| Shooters World Long Rifle | <<locked>> | 96% | 53,214 psi | 85% | 2448 fps | 99.1% |
| Shooters World Match Rifle | <<locked>> | 86% | 53,635 psi | 86% | 2441 fps | 100% |
| Shooters World Precision | <<locked>> | 90% | 54,172 psi | 87% | 2441 fps | 100% |
| Shooters World SW4350 | <<locked>> | 98% | 54,070 psi | 87% | 2480 fps | 98.5% |
| SNPE Vectan SP 11 | <<locked>> | 92% | 53,287 psi | 85% | 2497 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 86% | 55,013 psi | 88% | 2464 fps | 99.7% |
| SNPE Vectan SP 9 | <<locked>> | 88% | 55,796 psi | 89% | 2480 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 54,433 psi | 87% | 2356 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 54,462 psi | 87% | 2356 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 53,679 psi | 86% | 2408 fps | 98.2% |
| Somchem S321 | <<locked>> | 82% | 53,925 psi | 86% | 2444 fps | 100% |
| Somchem S335 | <<locked>> | 86% | 53,650 psi | 86% | 2356 fps | 100% |
| Somchem S341 | <<locked>> | 86% | 54,636 psi | 88% | 2454 fps | 100% |
| Somchem S355 | <<locked>> | 94% | 55,419 psi | 89% | 2484 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 49,835 psi | 80% | 2503 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 46,412 psi | 74% | 2402 fps | 96.4% |
| Vihtavuori N130 | <<locked>> | 82% | 54,056 psi | 87% | 2316 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 54,665 psi | 88% | 2339 fps | 100% |
| Vihtavuori N135 | <<locked>> | 90% | 56,333 psi | 90% | 2415 fps | 100% |
| Vihtavuori N140 | <<locked>> | 88% | 53,708 psi | 86% | 2392 fps | 100% |
| Vihtavuori N150 | <<locked>> | 94% | 53,592 psi | 86% | 2421 fps | 100% |
| Vihtavuori N160 | <<locked>> | 98% | 54,592 psi | 88% | 2497 fps | 99.8% |
| Vihtavuori N530 | <<locked>> | 84% | 53,417 psi | 86% | 2415 fps | 100% |
| Vihtavuori N540 | <<locked>> | 90% | 55,085 psi | 88% | 2431 fps | 100% |
| Vihtavuori N550 | <<locked>> | 98% | 53,476 psi | 86% | 2503 fps | 99.7% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 42,293 psi | 68% | 2402 fps | 99.2% |
| Winchester 6.5 StaBALL | <<locked>> | 98% | 54,810 psi | 88% | 2480 fps | 100% |
| Winchester 748 | <<locked>> | 84% | 53,359 psi | 86% | 2457 fps | 100% |
| Winchester 760 | <<locked>> | 98% | 55,883 psi | 90% | 2559 fps | 98.7% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 34,563 psi | 55% | 2343 fps | 99.3% |
| Winchester StaBALL Match | <<locked>> | 88% | 55,448 psi | 89% | 2487 fps | 100% |
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 2015 | <<locked>> | 80% | 48,646 psi | 78% | 2287 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 41,365 psi | 66% | 2228 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 48,138 psi | 77% | 2359 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 43,381 psi | 70% | 2251 fps | 95.3% |
| Accurate 3100 | <<locked>> | 96% | 35,085 psi | 56% | 2211 fps | 95% |
| Accurate 4064 | <<locked>> | 80% | 39,117 psi | 63% | 2228 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 30,574 psi | 49% | 2126 fps | 95.3% |
| ADI AR 2206H | <<locked>> | 80% | 44,860 psi | 72% | 2326 fps | 99.6% |
| ADI AR 2208 | <<locked>> | 80% | 38,101 psi | 61% | 2195 fps | 98.1% |
| ADI Benchmark 8208 | <<locked>> | 80% | 46,949 psi | 75% | 2329 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 47,398 psi | 76% | 2313 fps | 100% |
| Alliant Power Pro 2000-MR | 52.6 gr | 80% | 40,669 psi | 65% | 2359 fps | 98.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 37,855 psi | 61% | 2221 fps | 99.3% |
| Alliant Reloder-15 | <<locked>> | 80% | 40,596 psi | 65% | 2274 fps | 98.8% |
| Alliant Reloder-16 | <<locked>> | 82% | 31,299 psi | 50% | 2139 fps | 95.5% |
| Alliant Reloder-17 | 51.8 gr | 80% | 32,547 psi | 52% | 2198 fps | 97.8% |
| Alliant Reloder-23 | <<locked>> | 88% | 26,948 psi | 43% | 2057 fps | 95% |
| Alliant Reloder-26 | <<locked>> | 92% | 32,663 psi | 52% | 2257 fps | 95.1% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 43,874 psi | 70% | 2333 fps | 98.9% |
| Bofors RP3 | <<locked>> | 80% | 37,362 psi | 60% | 2221 fps | 99.3% |
| Bofors RP7 | <<locked>> | 88% | 43,410 psi | 70% | 2290 fps | 95.6% |
| Hodgdon Benchmark | <<locked>> | 80% | 48,559 psi | 78% | 2316 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 45,672 psi | 73% | 2352 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 80% | 50,386 psi | 81% | 2480 fps | 99.9% |
| Hodgdon H380 | <<locked>> | 80% | 38,116 psi | 61% | 2224 fps | 97.2% |
| Hodgdon H414 | <<locked>> | 88% | 40,161 psi | 64% | 2313 fps | 95.5% |
| Hodgdon H4350 | <<locked>> | 88% | 43,990 psi | 71% | 2333 fps | 95% |
| Hodgdon H4895 | <<locked>> | 80% | 45,310 psi | 73% | 2336 fps | 99.9% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 26,992 psi | 43% | 2008 fps | 95.5% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 41,234 psi | 66% | 2316 fps | 99.7% |
| Hodgdon Superformance | 61.6 gr | 90% | 42,670 psi | 68% | 2379 fps | 95.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,440 psi | 42% | 1312 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 43,337 psi | 69% | 2293 fps | 99.7% |
| IMR 3031 | <<locked>> | 80% | 44,976 psi | 72% | 2323 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 40,016 psi | 64% | 2224 fps | 98.7% |
| IMR 4166 Enduron | <<locked>> | 80% | 42,351 psi | 68% | 2241 fps | 95.9% |
| IMR 4350 | <<locked>> | 92% | 43,497 psi | 70% | 2316 fps | 95.7% |
| IMR 4451 Enduron | <<locked>> | 84% | 39,914 psi | 64% | 2228 fps | 95.1% |
| IMR 4831 | <<locked>> | 82% | 29,878 psi | 48% | 2093 fps | 95% |
| IMR 4895 | <<locked>> | 80% | 41,597 psi | 67% | 2300 fps | 99.3% |
| IMR 8208 XBR | <<locked>> | 80% | 46,949 psi | 75% | 2329 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 44,005 psi | 71% | 2306 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 44,773 psi | 72% | 2267 fps | 99.6% |
| Lovex S062 | <<locked>> | 80% | 39,914 psi | 64% | 2228 fps | 99.7% |
| Lovex S065 | <<locked>> | 82% | 34,911 psi | 56% | 2139 fps | 95.2% |
| Lovex S070 | <<locked>> | 88% | 39,769 psi | 64% | 2251 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 43,947 psi | 70% | 2283 fps | 99.9% |
| Norma 202 | <<locked>> | 80% | 44,295 psi | 71% | 2287 fps | 100% |
| Norma 203B | <<locked>> | 80% | 39,972 psi | 64% | 2264 fps | 99.1% |
| Norma 204 | <<locked>> | 96% | 49,356 psi | 79% | 2444 fps | 95.7% |
| Norma MRP | <<locked>> | 98% | 40,335 psi | 65% | 2385 fps | 95.1% |
| Norma URP | <<locked>> | 82% | 31,053 psi | 50% | 2126 fps | 95.2% |
| Ramshot Big Game | <<locked>> | 80% | 39,378 psi | 63% | 2277 fps | 98.9% |
| Ramshot Hunter | <<locked>> | 88% | 36,883 psi | 59% | 2257 fps | 95.3% |
| Ramshot TAC | <<locked>> | 80% | 46,586 psi | 75% | 2339 fps | 98.4% |
| Ramshot Wild Boar | <<locked>> | 80% | 46,093 psi | 74% | 2356 fps | 99.7% |
| Ramshot X-Terminator | <<locked>> | 80% | 50,473 psi | 81% | 2372 fps | 99.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,963 psi | 43% | 1348 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 52,388 psi | 84% | 2395 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 38,479 psi | 62% | 2208 fps | 95.6% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 42,641 psi | 68% | 2365 fps | 99.1% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 34,635 psi | 56% | 2254 fps | 99.9% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 32,489 psi | 52% | 2188 fps | 95.6% |
| ReloadSwiss RS 70 | <<locked>> | 86% | 34,882 psi | 56% | 2241 fps | 95.5% |
| Rottweil R 901 | <<locked>> | 80% | 47,964 psi | 77% | 2313 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 41,858 psi | 67% | 2241 fps | 99.8% |
| Rottweil R 903 | <<locked>> | 80% | 35,157 psi | 56% | 2175 fps | 98.7% |
| Rottweil R 907 | <<locked>> | 88% | 43,410 psi | 70% | 2290 fps | 95.6% |
| Shooters World Long Rifle | <<locked>> | 82% | 34,911 psi | 56% | 2139 fps | 95.2% |
| Shooters World Match Rifle | <<locked>> | 80% | 44,005 psi | 71% | 2306 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 39,914 psi | 64% | 2228 fps | 99.7% |
| Shooters World SW4350 | <<locked>> | 88% | 39,769 psi | 64% | 2251 fps | 95.5% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 36,114 psi | 58% | 2221 fps | 98.2% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 45,063 psi | 72% | 2320 fps | 98.5% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 43,294 psi | 69% | 2300 fps | 99.5% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 45,295 psi | 73% | 2238 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 37,739 psi | 61% | 2126 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 38,798 psi | 62% | 2178 fps | 95% |
| Somchem S321 | <<locked>> | 80% | 50,560 psi | 81% | 2398 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 44,860 psi | 72% | 2238 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 44,657 psi | 72% | 2313 fps | 99.6% |
| Somchem S355 | <<locked>> | 80% | 36,071 psi | 58% | 2178 fps | 98.7% |
| Somchem S365 | <<locked>> | 80% | 26,179 psi | 42% | 2041 fps | 96.7% |
| Somchem S385 | <<locked>> | 98% | 43,337 psi | 69% | 2349 fps | 95.6% |
| Vihtavuori N130 | <<locked>> | 80% | 51,126 psi | 82% | 2280 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 45,672 psi | 73% | 2228 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 41,394 psi | 66% | 2221 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 41,814 psi | 67% | 2231 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 34,200 psi | 55% | 2123 fps | 99.2% |
| Vihtavuori N160 | <<locked>> | 82% | 32,503 psi | 52% | 2129 fps | 95.7% |
| Vihtavuori N530 | <<locked>> | 80% | 46,963 psi | 75% | 2326 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 40,190 psi | 64% | 2224 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 31,923 psi | 51% | 2133 fps | 95.3% |
| Vihtavuori N555 | <<locked>> | 88% | 28,689 psi | 46% | 2123 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 30,255 psi | 49% | 2064 fps | 97.1% |
| Winchester 748 | <<locked>> | 80% | 46,644 psi | 75% | 2369 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 40,335 psi | 65% | 2316 fps | 95.6% |
| Winchester StaBALL HD | <<locked>> | 92% | 26,861 psi | 43% | 2119 fps | 95.2% |
| Winchester StaBALL Match | <<locked>> | 80% | 42,583 psi | 68% | 2303 fps | 99.7% |
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 99 powders for 8.5 x 55 Blaser loaded with the .338 | 250gr | Speer Grand Slam. ReloadSwiss RS 70 delivers the highest muzzle velocity at 2,605 fps; across all powders the maximum-charge window runs from 1,473 fps to 2,605 fps. Accurate 3100 gives the best case fill at 100 %, and 99 of the 99 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (430 MPa), the top charges use 55–90 %, leaving at least 10 % headroom. The 250.0 gr projectile in 0.338" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, Alliant Reloder-16, Alliant Reloder-23 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 Superformance, Alliant Reloder-17 rank at the top here: for 8.5 x 55 Blaser with the .338 | 250gr | Speer Grand Slam 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.