Load Specifications
Bullet Manufacturer:Speer
Bullet Weight:250 gr
Bullet Diameter:0.338"
Bullet Length:<<locked>>
Caliber:8.5 x 63 load data
Case Length (l3):2.48"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:75.5 Grains of Water
Primer Size:Large Rifle (LR)
Barrel Length:23.62"
Max. allowed Pressure:62,366 psi
Recommended Twist Rate:1:6.0
Load data in caliber 8.5 x 63 with .338 | 250gr | Speer Grand Slam bullet and 102 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-17, ReloadSwiss RS 60 and Alliant Power Pro 2000-MR.
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: 23.62"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 84% | 53,896 psi | 86% | 2336 fps | 100% |
| Accurate 2460 | <<locked>> | 82% | 55,405 psi | 89% | 2398 fps | 100% |
| Accurate 2495 | <<locked>> | 90% | 55,521 psi | 89% | 2398 fps | 100% |
| Accurate 2520 | <<locked>> | 86% | 55,782 psi | 89% | 2448 fps | 100% |
| Accurate 2520 | <<locked>> | 86% | 55,782 psi | 89% | 2448 fps | 100% |
| Accurate 2700 | <<locked>> | 94% | 55,999 psi | 90% | 2411 fps | 97.6% |
| Accurate 3100ᴾ | <<locked>> | 100% | 38,914 psi | 62% | 2267 fps | 95.9% |
| Accurate 4064 | <<locked>> | 92% | 55,405 psi | 89% | 2441 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 54,795 psi | 88% | 2520 fps | 99.8% |
| ADI AR 2206H | <<locked>> | 88% | 56,173 psi | 90% | 2470 fps | 100% |
| ADI AR 2208 | <<locked>> | 92% | 53,780 psi | 86% | 2428 fps | 99.9% |
| ADI Benchmark 8208 | <<locked>> | 86% | 55,274 psi | 89% | 2428 fps | 100% |
| Alliant AR-Comp | <<locked>> | 86% | 55,999 psi | 90% | 2398 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 90% | 55,535 psi | 89% | 2579 fps | 100% |
| Alliant Reloder- TS 15.5 | <<locked>> | 92% | 53,534 psi | 86% | 2448 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 90% | 54,186 psi | 87% | 2467 fps | 99.9% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 52,707 psi | 85% | 2520 fps | 99.9% |
| Alliant Reloder-17 | <<locked>> | 96% | 53,751 psi | 86% | 2552 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 37,637 psi | 60% | 2297 fps | 98.9% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 41,597 psi | 67% | 2431 fps | 98% |
| Baschieri & Pellagri 107 | <<locked>> | 88% | 55,782 psi | 89% | 2487 fps | 99.9% |
| Bofors RP3 | <<locked>> | 92% | 53,969 psi | 87% | 2461 fps | 100% |
| Bofors RP7 | <<locked>> | 96% | 54,143 psi | 87% | 2434 fps | 97.6% |
| Hodgdon Benchmark | <<locked>> | 84% | 53,708 psi | 86% | 2369 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 86% | 54,462 psi | 87% | 2457 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 84% | 56,304 psi | 90% | 2543 fps | 100% |
| Hodgdon H322 | <<locked>> | 84% | 55,274 psi | 89% | 2408 fps | 100% |
| Hodgdon H380 | <<locked>> | 92% | 55,013 psi | 88% | 2474 fps | 99.6% |
| Hodgdon H414 | <<locked>> | 96% | 55,811 psi | 89% | 2539 fps | 98.5% |
| Hodgdon H4350 | <<locked>> | 98% | 53,156 psi | 85% | 2454 fps | 96.8% |
| Hodgdon H4895 | <<locked>> | 86% | 53,374 psi | 86% | 2438 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 49,182 psi | 79% | 2415 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 92% | 55,912 psi | 90% | 2510 fps | 100% |
| Hodgdon Superformance | <<locked>> | 98% | 54,868 psi | 88% | 2549 fps | 97.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,491 psi | 57% | 1457 fps | 100% |
| Hodgdon VARGET | <<locked>> | 90% | 53,316 psi | 85% | 2421 fps | 100% |
| IMR 3031 | <<locked>> | 90% | 55,143 psi | 88% | 2441 fps | 100% |
| IMR 4064 | <<locked>> | 94% | 55,840 psi | 90% | 2444 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 94% | 55,259 psi | 89% | 2421 fps | 98.2% |
| IMR 4350ᴾ | <<locked>> | 100% | 54,230 psi | 87% | 2457 fps | 97.7% |
| IMR 4451 Enduron | <<locked>> | 96% | 56,101 psi | 90% | 2461 fps | 98.3% |
| IMR 4831ᴾ | <<locked>> | 100% | 46,253 psi | 74% | 2385 fps | 99.1% |
| IMR 4895 | <<locked>> | 90% | 55,521 psi | 89% | 2490 fps | 100% |
| IMR 8208 XBR | <<locked>> | 86% | 55,274 psi | 89% | 2428 fps | 100% |
| Lovex D073.5 | <<locked>> | 82% | 55,477 psi | 89% | 2415 fps | 100% |
| Lovex D073.6 | <<locked>> | 88% | 55,782 psi | 89% | 2448 fps | 100% |
| Lovex S060 | <<locked>> | 88% | 55,680 psi | 89% | 2402 fps | 100% |
| Lovex S062 | <<locked>> | 92% | 56,362 psi | 90% | 2451 fps | 100% |
| Lovex S065 | <<locked>> | 98% | 55,259 psi | 89% | 2454 fps | 99.2% |
| Lovex S070ᴾ | <<locked>> | 100% | 56,275 psi | 90% | 2487 fps | 98.6% |
| Norma 201 | <<locked>> | 88% | 54,810 psi | 88% | 2421 fps | 100% |
| Norma 202 | <<locked>> | 88% | 55,347 psi | 89% | 2421 fps | 100% |
| Norma 203B | <<locked>> | 90% | 53,359 psi | 86% | 2454 fps | 100% |
| Norma 204ᴾ | <<locked>> | 100% | 54,839 psi | 88% | 2500 fps | 96.5% |
| Norma URPᴾ | <<locked>> | 100% | 54,041 psi | 87% | 2510 fps | 99.7% |
| Ramshot Big Game | <<locked>> | 90% | 53,592 psi | 86% | 2477 fps | 100% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 52,736 psi | 85% | 2507 fps | 98.7% |
| Ramshot TAC | <<locked>> | 86% | 55,361 psi | 89% | 2448 fps | 99.3% |
| Ramshot Wild Boar | <<locked>> | 86% | 54,882 psi | 88% | 2461 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 84% | 56,159 psi | 90% | 2431 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,969 psi | 58% | 1493 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 82% | 54,607 psi | 88% | 2405 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 92% | 55,303 psi | 89% | 2457 fps | 98.7% |
| ReloadSwiss RS 52 | <<locked>> | 88% | 54,418 psi | 87% | 2523 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 94% | 53,766 psi | 86% | 2552 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 54,317 psi | 87% | 2539 fps | 99.7% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 54,172 psi | 87% | 2562 fps | 99.6% |
| Rottweil R 901 | <<locked>> | 86% | 56,028 psi | 90% | 2402 fps | 100% |
| Rottweil R 902 | <<locked>> | 90% | 55,230 psi | 89% | 2418 fps | 100% |
| Rottweil R 903 | <<locked>> | 94% | 53,809 psi | 86% | 2451 fps | 100% |
| Rottweil R 907 | <<locked>> | 96% | 54,143 psi | 87% | 2434 fps | 97.6% |
| Shooters World Long Rifle | <<locked>> | 98% | 55,259 psi | 89% | 2454 fps | 99.2% |
| Shooters World Match Rifle | <<locked>> | 88% | 55,782 psi | 89% | 2448 fps | 100% |
| Shooters World Precision | <<locked>> | 92% | 56,362 psi | 90% | 2451 fps | 100% |
| Shooters World SW4350ᴾ | <<locked>> | 100% | 56,275 psi | 90% | 2487 fps | 98.6% |
| SNPE Vectan SP 11 | <<locked>> | 94% | 55,347 psi | 89% | 2507 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 86% | 53,911 psi | 86% | 2431 fps | 99.4% |
| SNPE Vectan SP 9 | <<locked>> | 88% | 54,433 psi | 87% | 2448 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 53,388 psi | 86% | 2326 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 53,272 psi | 85% | 2326 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 98% | 55,666 psi | 89% | 2415 fps | 98.2% |
| Somchem S321 | <<locked>> | 84% | 56,347 psi | 90% | 2454 fps | 100% |
| Somchem S335 | <<locked>> | 88% | 55,695 psi | 89% | 2362 fps | 100% |
| Somchem S341 | <<locked>> | 86% | 53,301 psi | 85% | 2418 fps | 100% |
| Somchem S355 | <<locked>> | 94% | 54,273 psi | 87% | 2451 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 48,312 psi | 77% | 2464 fps | 100% |
| Unknown powder | <<locked>> | 98% | 55,129 psi | 88% | 2513 fps | 99.6% |
| Vihtavuori N130 | <<locked>> | 84% | 56,289 psi | 90% | 2326 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 53,606 psi | 86% | 2313 fps | 100% |
| Vihtavuori N135 | <<locked>> | 90% | 54,897 psi | 88% | 2382 fps | 100% |
| Vihtavuori N140 | <<locked>> | 90% | 55,898 psi | 90% | 2402 fps | 100% |
| Vihtavuori N150 | <<locked>> | 96% | 55,680 psi | 89% | 2431 fps | 100% |
| Vihtavuori N160 | <<locked>> | 98% | 53,040 psi | 85% | 2457 fps | 99.6% |
| Vihtavuori N530 | <<locked>> | 86% | 55,608 psi | 89% | 2425 fps | 100% |
| Vihtavuori N540 | <<locked>> | 90% | 54,027 psi | 87% | 2405 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 55,390 psi | 89% | 2510 fps | 99.7% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 40,799 psi | 65% | 2362 fps | 98.8% |
| Winchester 6.5 StaBALL | <<locked>> | 98% | 53,316 psi | 85% | 2444 fps | 100% |
| Winchester 748 | <<locked>> | 84% | 56,101 psi | 90% | 2477 fps | 100% |
| Winchester 760 | <<locked>> | 96% | 55,811 psi | 89% | 2539 fps | 98.5% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 33,620 psi | 54% | 2297 fps | 98.6% |
| Winchester StaBALL Match | <<locked>> | 82% | 55,767 psi | 89% | 2474 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% | 47,703 psi | 76% | 2257 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 52,054 psi | 83% | 2359 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 40,234 psi | 65% | 2198 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 45,571 psi | 73% | 2316 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 45,571 psi | 73% | 2316 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 46,079 psi | 74% | 2274 fps | 95.6% |
| Accurate 3100 | <<locked>> | 98% | 36,347 psi | 58% | 2221 fps | 95% |
| Accurate 4064 | <<locked>> | 80% | 38,043 psi | 61% | 2195 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 31,778 psi | 51% | 2136 fps | 95.5% |
| ADI AR 2206H | <<locked>> | 80% | 43,903 psi | 70% | 2293 fps | 99.4% |
| ADI AR 2208 | <<locked>> | 80% | 37,391 psi | 60% | 2165 fps | 97.7% |
| ADI Benchmark 8208 | <<locked>> | 80% | 45,934 psi | 74% | 2300 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 46,064 psi | 74% | 2280 fps | 100% |
| Alliant Power Pro 2000-MR | 51.3 gr | 80% | 39,624 psi | 64% | 2320 fps | 98.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 36,869 psi | 59% | 2185 fps | 98.9% |
| Alliant Reloder-15 | <<locked>> | 80% | 39,610 psi | 64% | 2238 fps | 98.4% |
| Alliant Reloder-16 | <<locked>> | 84% | 32,532 psi | 52% | 2149 fps | 95.6% |
| Alliant Reloder-17 | 50.5 gr | 80% | 31,662 psi | 51% | 2159 fps | 97.2% |
| Alliant Reloder-23 | <<locked>> | 90% | 27,876 psi | 45% | 2067 fps | 95.1% |
| Alliant Reloder-26 | <<locked>> | 94% | 33,866 psi | 54% | 2264 fps | 95.2% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 42,772 psi | 69% | 2297 fps | 98.6% |
| Bofors RP3 | <<locked>> | 80% | 36,390 psi | 58% | 2188 fps | 99% |
| Bofors RP7 | <<locked>> | 88% | 42,438 psi | 68% | 2251 fps | 95% |
| Hodgdon Benchmark | <<locked>> | 80% | 47,587 psi | 76% | 2283 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 44,454 psi | 71% | 2316 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 80% | 49,081 psi | 79% | 2441 fps | 99.7% |
| Hodgdon H322 | <<locked>> | 80% | 48,849 psi | 78% | 2326 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 37,217 psi | 60% | 2192 fps | 96.7% |
| Hodgdon H414 | <<locked>> | 86% | 40,030 psi | 64% | 2293 fps | 95.1% |
| Hodgdon H4350 | <<locked>> | 94% | 47,210 psi | 76% | 2365 fps | 95.5% |
| Hodgdon H4895 | <<locked>> | 80% | 44,266 psi | 71% | 2303 fps | 99.7% |
| Hodgdon Hybrid 100V | <<locked>> | 82% | 27,963 psi | 45% | 2018 fps | 95.6% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 37,724 psi | 60% | 2238 fps | 99.2% |
| Hodgdon Superformance | <<locked>> | 92% | 44,469 psi | 71% | 2388 fps | 95.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,353 psi | 42% | 1299 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 39,349 psi | 63% | 2205 fps | 99.1% |
| IMR 3031 | <<locked>> | 80% | 40,176 psi | 64% | 2238 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 36,608 psi | 59% | 2146 fps | 97.8% |
| IMR 4166 Enduron | <<locked>> | 84% | 41,104 psi | 66% | 2201 fps | 95.2% |
| IMR 4350 | <<locked>> | 92% | 42,380 psi | 68% | 2277 fps | 95% |
| IMR 4451 Enduron | <<locked>> | 86% | 41,626 psi | 67% | 2238 fps | 95.3% |
| IMR 4831 | <<locked>> | 88% | 31,705 psi | 51% | 2119 fps | 95.5% |
| IMR 4895 | <<locked>> | 80% | 40,582 psi | 65% | 2264 fps | 99% |
| IMR 8208 XBR | <<locked>> | 80% | 45,934 psi | 74% | 2300 fps | 100% |
| Lovex D073.5 | <<locked>> | 80% | 51,851 psi | 83% | 2369 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 42,728 psi | 69% | 2274 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 44,019 psi | 71% | 2238 fps | 99.4% |
| Lovex S062 | <<locked>> | 80% | 39,131 psi | 63% | 2198 fps | 99.5% |
| Lovex S065 | <<locked>> | 84% | 36,289 psi | 58% | 2149 fps | 95.3% |
| Lovex S070 | <<locked>> | 90% | 41,292 psi | 66% | 2260 fps | 95.7% |
| Norma 201 | <<locked>> | 80% | 42,917 psi | 69% | 2251 fps | 99.8% |
| Norma 202 | <<locked>> | 80% | 43,221 psi | 69% | 2257 fps | 100% |
| Norma 203B | <<locked>> | 80% | 39,001 psi | 63% | 2231 fps | 98.7% |
| Norma 204 | <<locked>> | 98% | 51,169 psi | 82% | 2448 fps | 95.7% |
| Norma URP | <<locked>> | 84% | 32,271 psi | 52% | 2136 fps | 95.4% |
| Ramshot Big Game | <<locked>> | 80% | 38,305 psi | 61% | 2241 fps | 98.5% |
| Ramshot Hunter | <<locked>> | 90% | 38,319 psi | 61% | 2267 fps | 95.5% |
| Ramshot TAC | <<locked>> | 80% | 45,571 psi | 73% | 2303 fps | 98% |
| Ramshot Wild Boar | <<locked>> | 80% | 45,194 psi | 72% | 2323 fps | 99.5% |
| Ramshot X-Terminator | <<locked>> | 80% | 49,327 psi | 79% | 2339 fps | 99.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,658 psi | 43% | 1329 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 51,358 psi | 82% | 2362 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 40,306 psi | 65% | 2224 fps | 95.8% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 41,321 psi | 66% | 2326 fps | 98.8% |
| ReloadSwiss RS 60 | 50.5 gr | 80% | 33,721 psi | 54% | 2215 fps | 99.6% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 33,823 psi | 54% | 2198 fps | 95.8% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 36,303 psi | 58% | 2254 fps | 95.7% |
| Rottweil R 901 | <<locked>> | 80% | 47,050 psi | 75% | 2283 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 40,843 psi | 65% | 2208 fps | 99.7% |
| Rottweil R 903 | <<locked>> | 80% | 34,185 psi | 55% | 2139 fps | 98.2% |
| Rottweil R 907 | <<locked>> | 88% | 42,438 psi | 68% | 2251 fps | 95% |
| Shooters World Long Rifle | <<locked>> | 84% | 36,289 psi | 58% | 2149 fps | 95.3% |
| Shooters World Match Rifle | <<locked>> | 80% | 42,728 psi | 69% | 2274 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 39,131 psi | 63% | 2198 fps | 99.5% |
| Shooters World SW4350 | <<locked>> | 90% | 41,292 psi | 66% | 2260 fps | 95.7% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 35,085 psi | 56% | 2182 fps | 97.7% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 43,990 psi | 71% | 2283 fps | 98.1% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 42,177 psi | 68% | 2264 fps | 99.2% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 44,498 psi | 71% | 2208 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 36,970 psi | 59% | 2096 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 40,335 psi | 65% | 2188 fps | 95.1% |
| Somchem S321 | <<locked>> | 80% | 49,356 psi | 79% | 2365 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 43,903 psi | 70% | 2208 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 43,540 psi | 70% | 2280 fps | 99.3% |
| Somchem S355 | <<locked>> | 80% | 35,128 psi | 56% | 2146 fps | 98.3% |
| Somchem S365 | <<locked>> | 80% | 25,483 psi | 41% | 2005 fps | 96% |
| Unknown powder | <<locked>> | 84% | 35,244 psi | 57% | 2188 fps | 95.7% |
| Vihtavuori N130 | <<locked>> | 80% | 50,227 psi | 81% | 2254 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 44,802 psi | 72% | 2201 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 40,437 psi | 65% | 2195 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 40,785 psi | 65% | 2198 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 33,301 psi | 53% | 2090 fps | 98.9% |
| Vihtavuori N160 | <<locked>> | 82% | 31,691 psi | 51% | 2093 fps | 95% |
| Vihtavuori N530 | <<locked>> | 80% | 45,948 psi | 74% | 2293 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 39,276 psi | 63% | 2195 fps | 100% |
| Vihtavuori N550 | <<locked>> | 84% | 33,185 psi | 53% | 2142 fps | 95.5% |
| Vihtavuori N555 | <<locked>> | 90% | 29,660 psi | 48% | 2129 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 29,559 psi | 47% | 2028 fps | 96.4% |
| Winchester 748 | <<locked>> | 80% | 48,892 psi | 78% | 2382 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 40,030 psi | 64% | 2293 fps | 95.1% |
| Winchester StaBALL HD | <<locked>> | 94% | 27,789 psi | 45% | 2126 fps | 95.4% |
| Winchester StaBALL Match | <<locked>> | 80% | 51,895 psi | 83% | 2425 fps | 100% |
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 102 powders for 8.5 x 63 loaded with the .338 | 250gr | Speer Grand Slam. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 2,579 fps; across all powders the maximum-charge window runs from 1,457 fps to 2,579 fps. Accurate 3100 gives the best case fill at 100 %, and 102 of the 102 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (430 MPa), the top charges use 54–90 %, 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, 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 Reloder-17, ReloadSwiss RS 60, Alliant Power Pro 2000-MR rank at the top here: for 8.5 x 63 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.