Load Specifications
Load data in caliber 8.5 x 55 Blaser with .338 | 220gr | Atomic 29 HP bullet and 97 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 Hodgdon LEVERevolution.
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>> | 90% | 55,912 psi | 90% | 2530 fps | 100% |
| Accurate 2200 | <<locked>> | 82% | 56,260 psi | 90% | 2625 fps | 99.4% |
| Accurate 2460 | <<locked>> | 86% | 54,128 psi | 87% | 2552 fps | 100% |
| Accurate 2495 | <<locked>> | 96% | 55,999 psi | 90% | 2582 fps | 100% |
| Accurate 2520 | <<locked>> | 90% | 55,796 psi | 89% | 2608 fps | 100% |
| Accurate 4064 | <<locked>> | 98% | 55,811 psi | 89% | 2621 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 44,570 psi | 71% | 2533 fps | 97.5% |
| Accurate LT-30 | <<locked>> | 84% | 55,941 psi | 90% | 2480 fps | 100% |
| Accurate LT-32 | <<locked>> | 84% | 56,405 psi | 90% | 2503 fps | 100% |
| ADI AR 2206H | <<locked>> | 92% | 54,795 psi | 88% | 2615 fps | 99.7% |
| ADI AR 2208 | <<locked>> | 98% | 55,970 psi | 90% | 2612 fps | 99.4% |
| ADI AR 2219 | <<locked>> | 82% | 52,808 psi | 85% | 2546 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 90% | 54,418 psi | 87% | 2579 fps | 100% |
| Alliant AR-Comp | <<locked>> | 90% | 53,896 psi | 86% | 2556 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 86% | 55,854 psi | 90% | 2671 fps | 99.9% |
| Alliant Power Pro 2000-MR | <<locked>> | 94% | 54,375 psi | 87% | 2720 fps | 99.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 98% | 54,926 psi | 88% | 2628 fps | 99.9% |
| Alliant Reloder-10x | <<locked>> | 86% | 55,927 psi | 90% | 2536 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 96% | 55,985 psi | 90% | 2654 fps | 99.6% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 45,049 psi | 72% | 2546 fps | 97.7% |
| Alliant Reloder-17ᴾ | <<locked>> | 100% | 51,996 psi | 83% | 2687 fps | 99.8% |
| Baschieri & Pellagri 106 | <<locked>> | 84% | 55,056 psi | 88% | 2480 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 92% | 54,578 psi | 88% | 2628 fps | 99.1% |
| Bofors RP3 | <<locked>> | 98% | 55,288 psi | 89% | 2644 fps | 100% |
| Hodgdon Benchmark | <<locked>> | 90% | 56,391 psi | 90% | 2562 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 90% | 52,866 psi | 85% | 2605 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 88% | 54,708 psi | 88% | 2690 fps | 99.5% |
| Hodgdon H322 | <<locked>> | 86% | 55,259 psi | 89% | 2579 fps | 100% |
| Hodgdon H335 | <<locked>> | 86% | 56,318 psi | 90% | 2605 fps | 100% |
| Hodgdon H380 | <<locked>> | 96% | 53,359 psi | 86% | 2605 fps | 98.5% |
| Hodgdon H4895 | <<locked>> | 92% | 55,259 psi | 89% | 2625 fps | 99.9% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 41,075 psi | 66% | 2438 fps | 98.2% |
| Hodgdon LEVERevolution | <<locked>> | 94% | 53,824 psi | 86% | 2654 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,374 psi | 55% | 1535 fps | 100% |
| Hodgdon VARGET | <<locked>> | 92% | 53,345 psi | 86% | 2582 fps | 99.8% |
| IMR 3031 | <<locked>> | 92% | 54,578 psi | 88% | 2612 fps | 100% |
| IMR 4064 | <<locked>> | 96% | 55,317 psi | 89% | 2595 fps | 99.5% |
| IMR 4166 Enduron | <<locked>> | 94% | 56,159 psi | 90% | 2579 fps | 96.9% |
| IMR 4198 | <<locked>> | 86% | 56,405 psi | 90% | 2497 fps | 100% |
| IMR 4451 Enduronᴾ | <<locked>> | 100% | 55,085 psi | 88% | 2592 fps | 96.6% |
| IMR 4831ᴾ | <<locked>> | 100% | 42,757 psi | 69% | 2484 fps | 97.2% |
| IMR 4895 | <<locked>> | 94% | 53,751 psi | 86% | 2631 fps | 99.7% |
| IMR 8208 XBR | <<locked>> | 90% | 54,418 psi | 87% | 2579 fps | 100% |
| Lovex D073.5 | <<locked>> | 86% | 54,230 psi | 87% | 2566 fps | 100% |
| Lovex D073.6 | <<locked>> | 92% | 53,853 psi | 86% | 2595 fps | 100% |
| Lovex S060 | <<locked>> | 92% | 55,405 psi | 89% | 2556 fps | 99.7% |
| Lovex S062 | <<locked>> | 96% | 54,447 psi | 87% | 2589 fps | 100% |
| Lovex S065ᴾ | <<locked>> | 100% | 50,169 psi | 80% | 2533 fps | 97.2% |
| Norma 200 | <<locked>> | 82% | 55,448 psi | 89% | 2507 fps | 100% |
| Norma 201 | <<locked>> | 92% | 53,548 psi | 86% | 2566 fps | 100% |
| Norma 202 | <<locked>> | 92% | 53,795 psi | 86% | 2569 fps | 100% |
| Norma 203B | <<locked>> | 96% | 55,013 psi | 88% | 2638 fps | 99.7% |
| Norma URPᴾ | <<locked>> | 100% | 45,063 psi | 72% | 2533 fps | 97.5% |
| Ramshot Big Game | <<locked>> | 96% | 55,405 psi | 89% | 2664 fps | 99.7% |
| Ramshot TAC | <<locked>> | 90% | 54,882 psi | 88% | 2592 fps | 98.1% |
| Ramshot Wild Boar | <<locked>> | 90% | 53,954 psi | 87% | 2608 fps | 99.6% |
| Ramshot X-Terminator | <<locked>> | 88% | 55,782 psi | 89% | 2582 fps | 99.6% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 34,664 psi | 56% | 1572 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 86% | 54,085 psi | 87% | 2562 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 96% | 54,027 psi | 87% | 2589 fps | 97.2% |
| ReloadSwiss RS 52 | <<locked>> | 94% | 55,985 psi | 90% | 2713 fps | 99.6% |
| ReloadSwiss RS 60ᴾ | <<locked>> | 100% | 55,709 psi | 89% | 2746 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 44,570 psi | 71% | 2552 fps | 97.2% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 45,905 psi | 74% | 2572 fps | 96.6% |
| Rottweil R 901 | <<locked>> | 90% | 54,317 psi | 87% | 2549 fps | 100% |
| Rottweil R 902 | <<locked>> | 94% | 53,722 psi | 86% | 2559 fps | 100% |
| Rottweil R 903ᴾ | <<locked>> | 100% | 54,868 psi | 88% | 2631 fps | 99.9% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 50,169 psi | 80% | 2533 fps | 97.2% |
| Shooters World Match Rifle | <<locked>> | 92% | 53,853 psi | 86% | 2595 fps | 100% |
| Shooters World Precision | <<locked>> | 96% | 54,447 psi | 87% | 2589 fps | 100% |
| Shooters World Tactical Rifle | <<locked>> | 84% | 53,838 psi | 86% | 2533 fps | 99.9% |
| SNPE Vectan BA6 1/2 | <<locked>> | 82% | 56,173 psi | 90% | 2244 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 82% | 53,345 psi | 86% | 2559 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 98% | 53,403 psi | 86% | 2644 fps | 99.6% |
| SNPE Vectan SP 3 | <<locked>> | 84% | 53,693 psi | 86% | 2516 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 92% | 56,275 psi | 90% | 2615 fps | 98.7% |
| SNPE Vectan SP 9 | <<locked>> | 92% | 53,316 psi | 85% | 2592 fps | 99.6% |
| SNPE Vectan Tubal 3000 | <<locked>> | 92% | 55,927 psi | 90% | 2516 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 98% | 55,390 psi | 89% | 2510 fps | 100% |
| SNPE Vectan Tubal 7000ᴾ | <<locked>> | 100% | 50,502 psi | 81% | 2490 fps | 95.7% |
| Somchem S321 | <<locked>> | 88% | 55,477 psi | 89% | 2612 fps | 100% |
| Somchem S335 | <<locked>> | 92% | 54,868 psi | 88% | 2516 fps | 100% |
| Somchem S341 | <<locked>> | 92% | 55,854 psi | 90% | 2608 fps | 99.7% |
| Somchem S355ᴾ | <<locked>> | 100% | 55,419 psi | 89% | 2628 fps | 99.9% |
| Somchem S365ᴾ | <<locked>> | 100% | 39,914 psi | 64% | 2484 fps | 99.2% |
| Vihtavuori N130 | <<locked>> | 88% | 55,796 psi | 89% | 2487 fps | 100% |
| Vihtavuori N133 | <<locked>> | 92% | 55,869 psi | 90% | 2503 fps | 100% |
| Vihtavuori N135 | <<locked>> | 96% | 56,304 psi | 90% | 2572 fps | 100% |
| Vihtavuori N140 | <<locked>> | 94% | 54,433 psi | 87% | 2552 fps | 100% |
| Vihtavuori N150ᴾ | <<locked>> | 100% | 53,824 psi | 86% | 2572 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 47,456 psi | 76% | 2533 fps | 97.8% |
| Vihtavuori N530 | <<locked>> | 90% | 54,781 psi | 88% | 2575 fps | 100% |
| Vihtavuori N540 | <<locked>> | 96% | 56,072 psi | 90% | 2595 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 46,470 psi | 75% | 2539 fps | 97.5% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 48,820 psi | 78% | 2526 fps | 99.5% |
| Winchester 748 | <<locked>> | 90% | 53,925 psi | 86% | 2618 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 92% | 52,939 psi | 85% | 2602 fps | 99.8% |
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% | 40,886 psi | 66% | 2323 fps | 100% |
| Accurate 2200 | <<locked>> | 80% | 52,591 psi | 84% | 2572 fps | 99% |
| Accurate 2460 | <<locked>> | 80% | 44,150 psi | 71% | 2411 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 32,837 psi | 53% | 2234 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 39,363 psi | 63% | 2365 fps | 99.6% |
| Accurate 4064 | <<locked>> | 80% | 31,125 psi | 50% | 2218 fps | 98.9% |
| Accurate 4350 | <<locked>> | 94% | 36,042 psi | 58% | 2379 fps | 95.2% |
| Accurate LT-30 | <<locked>> | 80% | 49,632 psi | 80% | 2398 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 50,067 psi | 80% | 2421 fps | 100% |
| ADI AR 2206H | <<locked>> | 80% | 37,492 psi | 60% | 2326 fps | 97% |
| ADI AR 2208 | <<locked>> | 82% | 34,127 psi | 55% | 2241 fps | 95% |
| ADI AR 2219 | <<locked>> | 80% | 49,385 psi | 79% | 2500 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 80% | 39,537 psi | 63% | 2343 fps | 98.6% |
| Alliant AR-Comp | <<locked>> | 80% | 38,580 psi | 62% | 2346 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 45,774 psi | 73% | 2520 fps | 99.2% |
| Alliant Power Pro 2000-MR | 51.2 gr | 82% | 36,085 psi | 58% | 2382 fps | 95.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 30,748 psi | 49% | 2205 fps | 95.8% |
| Alliant Reloder-10x | <<locked>> | 80% | 46,267 psi | 74% | 2408 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 33,373 psi | 54% | 2260 fps | 95% |
| Alliant Reloder-16 | <<locked>> | 94% | 37,521 psi | 60% | 2395 fps | 95.4% |
| Alliant Reloder-17 | <<locked>> | 86% | 32,561 psi | 52% | 2313 fps | 95.4% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 48,486 psi | 78% | 2398 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 36,448 psi | 58% | 2323 fps | 95.3% |
| Bofors RP3 | <<locked>> | 80% | 29,892 psi | 48% | 2198 fps | 95.6% |
| Hodgdon Benchmark | <<locked>> | 80% | 41,684 psi | 67% | 2339 fps | 99.3% |
| Hodgdon BL-C2 | <<locked>> | 80% | 37,362 psi | 60% | 2349 fps | 98.6% |
| Hodgdon CFE223 | <<locked>> | 80% | 41,234 psi | 66% | 2470 fps | 97.4% |
| Hodgdon H322 | <<locked>> | 80% | 45,107 psi | 72% | 2438 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 45,832 psi | 73% | 2461 fps | 100% |
| Hodgdon H380 | <<locked>> | 86% | 38,130 psi | 61% | 2352 fps | 95.1% |
| Hodgdon H4895 | <<locked>> | 80% | 37,724 psi | 60% | 2339 fps | 97.6% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 31,966 psi | 51% | 2247 fps | 95.3% |
| Hodgdon LEVERevolution | 49 gr | 80% | 33,707 psi | 54% | 2300 fps | 96.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,541 psi | 41% | 1371 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 36,347 psi | 58% | 2293 fps | 97.1% |
| IMR 3031 | <<locked>> | 80% | 36,637 psi | 59% | 2343 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 33,402 psi | 54% | 2218 fps | 95% |
| IMR 4166 Enduron | <<locked>> | 90% | 49,719 psi | 80% | 2484 fps | 95.5% |
| IMR 4198 | <<locked>> | 80% | 47,152 psi | 76% | 2379 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 96% | 48,733 psi | 78% | 2497 fps | 95.2% |
| IMR 4831 | <<locked>> | 96% | 37,536 psi | 60% | 2385 fps | 95.7% |
| IMR 4895 | <<locked>> | 80% | 34,127 psi | 55% | 2287 fps | 96% |
| IMR 8208 XBR | <<locked>> | 80% | 39,537 psi | 63% | 2343 fps | 98.6% |
| Lovex D073.5 | <<locked>> | 80% | 43,947 psi | 70% | 2418 fps | 99.7% |
| Lovex D073.6 | <<locked>> | 80% | 35,549 psi | 57% | 2306 fps | 99.1% |
| Lovex S060 | <<locked>> | 80% | 38,305 psi | 61% | 2277 fps | 97.2% |
| Lovex S062 | <<locked>> | 80% | 32,953 psi | 53% | 2224 fps | 97% |
| Lovex S065 | <<locked>> | 94% | 41,713 psi | 67% | 2395 fps | 95.1% |
| Norma 200 | <<locked>> | 80% | 52,185 psi | 84% | 2467 fps | 100% |
| Norma 201 | <<locked>> | 80% | 36,637 psi | 59% | 2287 fps | 98% |
| Norma 202 | <<locked>> | 80% | 36,651 psi | 59% | 2300 fps | 99.6% |
| Norma 203B | <<locked>> | 80% | 32,764 psi | 53% | 2251 fps | 95.5% |
| Norma URP | <<locked>> | 94% | 37,072 psi | 59% | 2382 fps | 95.2% |
| Ramshot Big Game | <<locked>> | 82% | 34,490 psi | 55% | 2306 fps | 95.7% |
| Ramshot TAC | <<locked>> | 82% | 42,047 psi | 67% | 2385 fps | 95.4% |
| Ramshot Wild Boar | <<locked>> | 80% | 38,421 psi | 62% | 2356 fps | 97.1% |
| Ramshot X-Terminator | <<locked>> | 80% | 42,757 psi | 69% | 2382 fps | 98% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 25,701 psi | 41% | 1404 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 44,425 psi | 71% | 2421 fps | 99.9% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 44,527 psi | 71% | 2441 fps | 95% |
| ReloadSwiss RS 52 | 48.4 gr | 80% | 34,330 psi | 55% | 2339 fps | 95.3% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 28,485 psi | 46% | 2211 fps | 96.2% |
| ReloadSwiss RS 62 | <<locked>> | 96% | 38,957 psi | 62% | 2448 fps | 95.6% |
| ReloadSwiss RS 70 | <<locked>> | 98% | 42,975 psi | 69% | 2516 fps | 95.7% |
| Rottweil R 901 | <<locked>> | 80% | 40,059 psi | 64% | 2329 fps | 99.8% |
| Rottweil R 902 | <<locked>> | 80% | 34,722 psi | 56% | 2241 fps | 97.5% |
| Rottweil R 903 | <<locked>> | 82% | 29,994 psi | 48% | 2195 fps | 95.2% |
| Shooters World Long Rifle | <<locked>> | 94% | 41,713 psi | 67% | 2395 fps | 95.1% |
| Shooters World Match Rifle | <<locked>> | 80% | 35,549 psi | 57% | 2306 fps | 99.1% |
| Shooters World Precision | <<locked>> | 80% | 32,953 psi | 53% | 2224 fps | 97% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 46,905 psi | 75% | 2434 fps | 99.4% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 53,519 psi | 86% | 2215 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 80% | 49,748 psi | 80% | 2510 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 33,649 psi | 54% | 2293 fps | 95.5% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 47,152 psi | 76% | 2428 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 39,929 psi | 64% | 2359 fps | 95.5% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 35,998 psi | 58% | 2297 fps | 96.5% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 38,348 psi | 61% | 2257 fps | 99.7% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 31,372 psi | 50% | 2136 fps | 99.3% |
| SNPE Vectan Tubal 7000 | <<locked>> | 98% | 47,326 psi | 76% | 2444 fps | 95% |
| Somchem S321 | <<locked>> | 80% | 42,380 psi | 68% | 2415 fps | 99.2% |
| Somchem S335 | <<locked>> | 80% | 37,869 psi | 61% | 2264 fps | 99.9% |
| Somchem S341 | <<locked>> | 80% | 37,086 psi | 59% | 2310 fps | 96.7% |
| Somchem S355 | <<locked>> | 82% | 31,285 psi | 50% | 2208 fps | 95.4% |
| Somchem S365 | <<locked>> | 90% | 28,993 psi | 46% | 2231 fps | 95.7% |
| Vihtavuori N130 | <<locked>> | 80% | 43,613 psi | 70% | 2326 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 38,522 psi | 62% | 2260 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 33,649 psi | 54% | 2238 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 34,722 psi | 56% | 2244 fps | 99.5% |
| Vihtavuori N150 | <<locked>> | 80% | 27,804 psi | 45% | 2106 fps | 95.6% |
| Vihtavuori N160 | <<locked>> | 94% | 39,073 psi | 63% | 2388 fps | 95.8% |
| Vihtavuori N530 | <<locked>> | 80% | 39,392 psi | 63% | 2336 fps | 98.6% |
| Vihtavuori N540 | <<locked>> | 80% | 33,272 psi | 53% | 2231 fps | 98.9% |
| Vihtavuori N550 | <<locked>> | 94% | 38,058 psi | 61% | 2388 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 32,648 psi | 52% | 2224 fps | 95.6% |
| Winchester 748 | <<locked>> | 80% | 38,319 psi | 61% | 2372 fps | 99% |
| Winchester StaBALL Match | <<locked>> | 80% | 35,027 psi | 56% | 2297 fps | 96.9% |
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 97 powders for 8.5 x 55 Blaser loaded with the .338 | 220gr | Atomic 29 HP. ReloadSwiss RS 60 delivers the highest muzzle velocity at 2,746 fps; across all powders the maximum-charge window runs from 1,535 fps to 2,746 fps. Accurate 4350 gives the best case fill at 100 %, and 97 of the 97 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 220.0 gr projectile in 0.338" calls for a 1:14.0 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, Hodgdon LEVERevolution rank at the top here: for 8.5 x 55 Blaser with the .338 | 220gr | Atomic 29 HP 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.