Load Specifications
Load data in caliber .338 Rem. Ultra Mag. with .338 | 245gr | Peregrine Glider GRM bullet and 95 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Accurate High Country, Alliant Reloder-26 and Norma MRP.
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: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 82% | 57,203 psi | 90% | 2513 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 55,042 psi | 86% | 2549 fps | 99.5% |
| Accurate 3100ᴾ | <<locked>> | 100% | 57,479 psi | 90% | 2644 fps | 100% |
| Accurate 4064 | <<locked>> | 82% | 54,201 psi | 85% | 2523 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 55,535 psi | 87% | 2631 fps | 100% |
| Accurate High Country | <<locked>> | 96% | 55,042 psi | 86% | 2733 fps | 98.8% |
| Accurate MAGPRO | <<locked>> | 98% | 56,101 psi | 88% | 2736 fps | 97.9% |
| ADI AR 2208 | <<locked>> | 84% | 54,578 psi | 86% | 2562 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 56,768 psi | 89% | 2684 fps | 99.4% |
| ADI AR 2213 | <<locked>> | 98% | 54,317 psi | 85% | 2684 fps | 98.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 37,072 psi | 58% | 2428 fps | 97.5% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 56,826 psi | 89% | 2680 fps | 99.4% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 56,826 psi | 89% | 2680 fps | 99.4% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 56,826 psi | 89% | 2680 fps | 99.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 55,434 psi | 87% | 2579 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 55,622 psi | 87% | 2602 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 56,637 psi | 89% | 2687 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 54,186 psi | 85% | 2657 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 56,057 psi | 88% | 2674 fps | 99.4% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 57,450 psi | 90% | 2730 fps | 99.6% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 54,288 psi | 85% | 2654 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 46,833 psi | 73% | 2605 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 96% | 54,520 psi | 85% | 2740 fps | 100% |
| Baschieri & Pellagri 109ᴾ | <<locked>> | 100% | 57,000 psi | 89% | 2648 fps | 96% |
| Bofors RP15ᴾ | <<locked>> | 100% | 52,518 psi | 82% | 2661 fps | 99.1% |
| Bofors RP3 | <<locked>> | 84% | 56,101 psi | 88% | 2592 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 42,743 psi | 67% | 2536 fps | 96.7% |
| Bofors RP5ᴾ | <<locked>> | 100% | 57,450 psi | 90% | 2730 fps | 99.6% |
| Bofors RP7 | <<locked>> | 88% | 55,419 psi | 87% | 2589 fps | 99.7% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 46,514 psi | 73% | 2552 fps | 97.7% |
| Hodgdon H380 | <<locked>> | 84% | 56,579 psi | 89% | 2615 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 54,027 psi | 85% | 2635 fps | 99.8% |
| Hodgdon H4350 | <<locked>> | 88% | 57,232 psi | 90% | 2648 fps | 99.6% |
| Hodgdon H4831 | <<locked>> | 96% | 54,534 psi | 85% | 2631 fps | 97.8% |
| Hodgdon H4831 SC | <<locked>> | 98% | 57,101 psi | 89% | 2664 fps | 98.2% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 56,942 psi | 89% | 2612 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 45,890 psi | 72% | 2648 fps | 98.9% |
| Hodgdon Superformance | <<locked>> | 88% | 54,418 psi | 85% | 2671 fps | 99.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,593 psi | 57% | 1614 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 57,479 psi | 90% | 2589 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 56,318 psi | 88% | 2579 fps | 99.9% |
| IMR 4350 | <<locked>> | 92% | 56,768 psi | 89% | 2621 fps | 99.8% |
| IMR 4451 Enduron | <<locked>> | 88% | 57,217 psi | 90% | 2615 fps | 99.9% |
| IMR 4831 | <<locked>> | 92% | 55,941 psi | 88% | 2625 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 57,058 psi | 89% | 2625 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 55,970 psi | 88% | 2618 fps | 98.2% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 55,492 psi | 87% | 2713 fps | 98.7% |
| Lovex S062 | <<locked>> | 84% | 57,537 psi | 90% | 2579 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 57,305 psi | 90% | 2608 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 55,259 psi | 87% | 2605 fps | 99.9% |
| Lovex S071ᴾ | <<locked>> | 100% | 47,485 psi | 74% | 2510 fps | 99.7% |
| Norma 203B | <<locked>> | 82% | 54,911 psi | 86% | 2589 fps | 100% |
| Norma 204 | <<locked>> | 90% | 54,041 psi | 85% | 2625 fps | 99% |
| Norma MRP | <<locked>> | 98% | 57,087 psi | 89% | 2753 fps | 100% |
| Norma URP | <<locked>> | 90% | 54,302 psi | 85% | 2621 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 55,709 psi | 87% | 2612 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 56,173 psi | 88% | 2730 fps | 99% |
| Ramshot Hunter | <<locked>> | 92% | 56,884 psi | 89% | 2674 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 50,125 psi | 79% | 2615 fps | 99.3% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,231 psi | 58% | 1654 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 56,536 psi | 89% | 2602 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 57,609 psi | 90% | 2694 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 55,564 psi | 87% | 2657 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 54,056 psi | 85% | 2684 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 46,021 psi | 72% | 2644 fps | 99.6% |
| Rottweil R 902 | <<locked>> | 82% | 56,014 psi | 88% | 2546 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 56,405 psi | 88% | 2592 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 54,694 psi | 86% | 2605 fps | 98.4% |
| Rottweil R 905 | <<locked>> | 96% | 55,332 psi | 87% | 2661 fps | 99.4% |
| Rottweil R 907 | <<locked>> | 88% | 55,419 psi | 87% | 2589 fps | 99.7% |
| Shooters World Long Rifle | <<locked>> | 90% | 57,305 psi | 90% | 2608 fps | 100% |
| Shooters World Precision | <<locked>> | 84% | 57,537 psi | 90% | 2579 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 55,259 psi | 87% | 2605 fps | 99.9% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 54,375 psi | 85% | 2598 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 57,101 psi | 89% | 2477 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 57,072 psi | 89% | 2569 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 54,853 psi | 86% | 2657 fps | 99.3% |
| Somchem S355 | <<locked>> | 86% | 56,202 psi | 88% | 2585 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 56,362 psi | 88% | 2598 fps | 98% |
| Somchem S365 | <<locked>> | 92% | 53,896 psi | 84% | 2618 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 55,970 psi | 88% | 2638 fps | 99.8% |
| Vihtavuori N135 | <<locked>> | 82% | 56,434 psi | 88% | 2500 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 56,623 psi | 89% | 2516 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 57,682 psi | 90% | 2559 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 56,376 psi | 88% | 2615 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 55,390 psi | 87% | 2615 fps | 99.6% |
| Vihtavuori N540 | <<locked>> | 82% | 54,795 psi | 86% | 2516 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 55,434 psi | 87% | 2618 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 56,724 psi | 89% | 2677 fps | 100% |
| Vihtavuori N560 | <<locked>> | 98% | 57,246 psi | 90% | 2749 fps | 98.6% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 48,834 psi | 77% | 2612 fps | 97.3% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 56,086 psi | 88% | 2579 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 54,244 psi | 85% | 2638 fps | 99.8% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 50,125 psi | 79% | 2720 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 56,202 psi | 88% | 2635 fps | 99.3% |
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 2495 | <<locked>> | 80% | 53,577 psi | 84% | 2470 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 51,532 psi | 81% | 2500 fps | 99.2% |
| Accurate 3100 | <<locked>> | 80% | 28,529 psi | 45% | 2142 fps | 95% |
| Accurate 4064 | <<locked>> | 80% | 50,836 psi | 80% | 2480 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 39,073 psi | 61% | 2382 fps | 99.5% |
| Accurate High Country | 75.1 gr | 88% | 41,379 psi | 65% | 2510 fps | 95.8% |
| Accurate MAGPRO | <<locked>> | 92% | 45,208 psi | 71% | 2566 fps | 95.5% |
| ADI AR 2208 | <<locked>> | 80% | 48,095 psi | 75% | 2470 fps | 100% |
| ADI AR 2209 | <<locked>> | 84% | 37,971 psi | 60% | 2372 fps | 95.6% |
| ADI AR 2213 | <<locked>> | 90% | 41,365 psi | 65% | 2464 fps | 95.2% |
| ADI AR 2225 | <<locked>> | 96% | 32,547 psi | 51% | 2316 fps | 95.4% |
| Alliant Power Pro Varmint | <<locked>> | 84% | 38,174 psi | 60% | 2375 fps | 95.8% |
| Alliant Power Pro Varmint | <<locked>> | 84% | 38,174 psi | 60% | 2375 fps | 95.8% |
| Alliant Power Pro Varmint | <<locked>> | 84% | 38,174 psi | 60% | 2375 fps | 95.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 48,820 psi | 77% | 2490 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 51,996 psi | 81% | 2552 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 38,087 psi | 60% | 2395 fps | 99.6% |
| Alliant Reloder-17 | <<locked>> | 80% | 43,511 psi | 68% | 2503 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 37,797 psi | 59% | 2369 fps | 95.7% |
| Alliant Reloder-22 | <<locked>> | 86% | 35,534 psi | 56% | 2359 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 80% | 27,789 psi | 44% | 2178 fps | 98.3% |
| Alliant Reloder-25 | <<locked>> | 86% | 29,573 psi | 46% | 2238 fps | 96% |
| Alliant Reloder-26 | 70.3 gr | 80% | 29,747 psi | 47% | 2283 fps | 97.1% |
| Baschieri & Pellagri 109 | <<locked>> | 98% | 53,577 psi | 84% | 2595 fps | 95.2% |
| Bofors RP15 | <<locked>> | 90% | 37,623 psi | 59% | 2402 fps | 95.6% |
| Bofors RP3 | <<locked>> | 80% | 49,052 psi | 77% | 2500 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 39,798 psi | 62% | 2477 fps | 95.8% |
| Bofors RP5 | <<locked>> | 86% | 35,534 psi | 56% | 2359 fps | 95% |
| Bofors RP7 | <<locked>> | 80% | 42,960 psi | 67% | 2395 fps | 98% |
| Hodgdon H1000 | <<locked>> | 96% | 40,509 psi | 63% | 2441 fps | 95.9% |
| Hodgdon H380 | <<locked>> | 80% | 49,356 psi | 77% | 2513 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 41,205 psi | 65% | 2428 fps | 98.2% |
| Hodgdon H4350 | <<locked>> | 80% | 44,092 psi | 69% | 2444 fps | 97.7% |
| Hodgdon H4831 | <<locked>> | 90% | 44,338 psi | 69% | 2470 fps | 95.5% |
| Hodgdon H4831 SC | <<locked>> | 90% | 43,424 psi | 68% | 2454 fps | 95.2% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 35,650 psi | 56% | 2297 fps | 99.8% |
| Hodgdon Retumbo | <<locked>> | 92% | 35,128 psi | 55% | 2411 fps | 95.2% |
| Hodgdon Superformance | <<locked>> | 80% | 40,176 psi | 63% | 2444 fps | 97.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,180 psi | 43% | 1440 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 50,604 psi | 79% | 2497 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 52,924 psi | 83% | 2533 fps | 99.7% |
| IMR 4350 | <<locked>> | 80% | 38,725 psi | 61% | 2333 fps | 97% |
| IMR 4451 Enduron | <<locked>> | 80% | 44,454 psi | 70% | 2421 fps | 98.7% |
| IMR 4831 | <<locked>> | 80% | 37,594 psi | 59% | 2343 fps | 99.3% |
| IMR 4895 | <<locked>> | 80% | 53,345 psi | 84% | 2575 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 43,410 psi | 68% | 2421 fps | 95.4% |
| IMR 7828 SSC | <<locked>> | 92% | 42,351 psi | 66% | 2493 fps | 95.7% |
| Lovex S062 | <<locked>> | 80% | 50,691 psi | 79% | 2490 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 41,901 psi | 66% | 2375 fps | 99.2% |
| Lovex S070 | <<locked>> | 80% | 40,089 psi | 63% | 2362 fps | 98.1% |
| Lovex S071 | <<locked>> | 86% | 29,921 psi | 47% | 2178 fps | 95.6% |
| Norma 203B | <<locked>> | 80% | 51,343 psi | 80% | 2539 fps | 100% |
| Norma 204 | <<locked>> | 80% | 38,276 psi | 60% | 2359 fps | 95.6% |
| Norma MRP | 70 gr | 82% | 32,314 psi | 51% | 2313 fps | 95.2% |
| Norma URP | <<locked>> | 80% | 38,928 psi | 61% | 2379 fps | 99.4% |
| Ramshot Big Game | <<locked>> | 80% | 52,112 psi | 82% | 2562 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 39,102 psi | 61% | 2444 fps | 95% |
| Ramshot Hunter | <<locked>> | 80% | 37,884 psi | 59% | 2372 fps | 98.2% |
| Ramshot Magnum | <<locked>> | 90% | 34,577 psi | 54% | 2329 fps | 95.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,804 psi | 44% | 1480 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 49,516 psi | 78% | 2503 fps | 99.7% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 46,267 psi | 73% | 2546 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 39,146 psi | 61% | 2405 fps | 99.4% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 37,826 psi | 59% | 2415 fps | 99.1% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 34,490 psi | 54% | 2398 fps | 96.3% |
| Rottweil R 902 | <<locked>> | 80% | 52,547 psi | 82% | 2500 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 46,195 psi | 72% | 2454 fps | 100% |
| Rottweil R 904 | <<locked>> | 86% | 42,076 psi | 66% | 2405 fps | 95.7% |
| Rottweil R 905 | <<locked>> | 84% | 36,883 psi | 58% | 2352 fps | 95.6% |
| Rottweil R 907 | <<locked>> | 80% | 42,960 psi | 67% | 2395 fps | 98% |
| Shooters World Long Rifle | <<locked>> | 80% | 41,901 psi | 66% | 2375 fps | 99.2% |
| Shooters World Precision | <<locked>> | 80% | 50,691 psi | 79% | 2490 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 40,089 psi | 63% | 2362 fps | 98.1% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 47,703 psi | 75% | 2507 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 47,427 psi | 74% | 2359 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 41,031 psi | 64% | 2326 fps | 98.1% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 36,535 psi | 57% | 2346 fps | 95.4% |
| Somchem S355 | <<locked>> | 80% | 46,427 psi | 73% | 2451 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 42,975 psi | 67% | 2395 fps | 95.1% |
| Somchem S365 | <<locked>> | 80% | 35,505 psi | 56% | 2339 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 34,983 psi | 55% | 2287 fps | 95.8% |
| Vihtavuori N135 | <<locked>> | 80% | 53,113 psi | 83% | 2461 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 53,185 psi | 83% | 2474 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 44,382 psi | 70% | 2385 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 40,364 psi | 63% | 2375 fps | 99.6% |
| Vihtavuori N165 | <<locked>> | 86% | 34,432 psi | 54% | 2267 fps | 95.2% |
| Vihtavuori N540 | <<locked>> | 80% | 51,314 psi | 80% | 2474 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 39,682 psi | 62% | 2379 fps | 99.4% |
| Vihtavuori N555 | <<locked>> | 80% | 30,777 psi | 48% | 2244 fps | 98.2% |
| Vihtavuori N560 | <<locked>> | 90% | 43,294 psi | 68% | 2526 fps | 95.6% |
| Vihtavuori N565 | <<locked>> | 96% | 42,380 psi | 66% | 2503 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 39,494 psi | 62% | 2346 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 41,379 psi | 65% | 2434 fps | 98.3% |
| Winchester StaBALL HD | <<locked>> | 80% | 24,468 psi | 38% | 2162 fps | 97.8% |
| Winchester Supreme 780 | <<locked>> | 86% | 36,651 psi | 57% | 2320 fps | 95.3% |
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 95 powders for .338 Rem. Ultra Mag. loaded with the .338 | 245gr | Peregrine Glider GRM. Norma MRP delivers the highest muzzle velocity at 2,753 fps; across all powders the maximum-charge window runs from 1,614 fps to 2,753 fps. Accurate 3100 gives the best case fill at 100 %, and 95 of the 95 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 245.0 gr projectile in 0.338" calls for a 1:10.0 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2225, Alliant Reloder-22 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. Accurate High Country, Alliant Reloder-26, Norma MRP rank at the top here: for .338 Rem. Ultra Mag. with the .338 | 245gr | Peregrine Glider GRM 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.