Load Specifications
Load data in caliber .338 Win Mag. with .338 | 185gr | Hornady CX bullet and 96 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 CFE223 and ReloadSwiss RS 52.
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 2015 | <<locked>> | 90% | 54,897 psi | 88% | 2808 fps | 100% |
| Accurate 2200 | <<locked>> | 82% | 55,230 psi | 89% | 2900 fps | 98.7% |
| Accurate 2230 | <<locked>> | 82% | 56,289 psi | 90% | 2913 fps | 99.1% |
| Accurate 2460 | <<locked>> | 86% | 53,330 psi | 86% | 2828 fps | 100% |
| Accurate 2495 | <<locked>> | 96% | 55,172 psi | 88% | 2864 fps | 100% |
| Accurate 2520 | <<locked>> | 90% | 54,868 psi | 88% | 2887 fps | 100% |
| Accurate 4064 | <<locked>> | 98% | 54,868 psi | 88% | 2900 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 43,743 psi | 70% | 2785 fps | 96.3% |
| Accurate LT-30 | <<locked>> | 84% | 55,288 psi | 89% | 2759 fps | 100% |
| Accurate LT-32 | <<locked>> | 84% | 55,709 psi | 89% | 2785 fps | 100% |
| ADI AR 2206H | <<locked>> | 92% | 53,969 psi | 87% | 2890 fps | 99.2% |
| ADI AR 2207 | <<locked>> | 82% | 56,434 psi | 90% | 2776 fps | 100% |
| ADI AR 2208 | <<locked>> | 98% | 55,056 psi | 88% | 2884 fps | 98.8% |
| ADI AR 2219 | <<locked>> | 84% | 55,622 psi | 89% | 2877 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 90% | 53,432 psi | 86% | 2851 fps | 99.7% |
| Alliant AR-Comp | <<locked>> | 90% | 52,794 psi | 85% | 2835 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 86% | 54,723 psi | 88% | 2956 fps | 99.6% |
| Alliant Power Pro 2000-MR | <<locked>> | 94% | 53,519 psi | 86% | 2995 fps | 98.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 98% | 53,940 psi | 86% | 2904 fps | 99.6% |
| Alliant Reloder-10x | <<locked>> | 86% | 54,824 psi | 88% | 2818 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 96% | 55,085 psi | 88% | 2927 fps | 99% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 44,353 psi | 71% | 2799 fps | 96.4% |
| Alliant Reloder-17ᴾ | <<locked>> | 100% | 51,300 psi | 82% | 2959 fps | 99.3% |
| Baschieri & Pellagri 106 | <<locked>> | 84% | 54,375 psi | 87% | 2756 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 92% | 53,969 psi | 87% | 2907 fps | 98.4% |
| Bofors RP3 | <<locked>> | 98% | 54,288 psi | 87% | 2920 fps | 99.7% |
| Hodgdon Benchmark | <<locked>> | 90% | 55,782 psi | 89% | 2841 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 92% | 55,738 psi | 89% | 2930 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 88% | 53,780 psi | 86% | 2969 fps | 98.9% |
| Hodgdon H322 | <<locked>> | 86% | 54,230 psi | 87% | 2858 fps | 100% |
| Hodgdon H335 | <<locked>> | 86% | 55,216 psi | 89% | 2881 fps | 100% |
| Hodgdon H380 | <<locked>> | 98% | 56,115 psi | 90% | 2930 fps | 98.1% |
| Hodgdon H4895 | <<locked>> | 92% | 54,418 psi | 87% | 2904 fps | 99.5% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 40,437 psi | 65% | 2684 fps | 97.1% |
| Hodgdon LEVERevolution | <<locked>> | 94% | 53,026 psi | 85% | 2930 fps | 99.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,185 psi | 55% | 1736 fps | 100% |
| Hodgdon VARGET | <<locked>> | 94% | 56,014 psi | 90% | 2907 fps | 99.6% |
| IMR 3031 | <<locked>> | 92% | 53,679 psi | 86% | 2897 fps | 100% |
| IMR 4064 | <<locked>> | 96% | 54,520 psi | 87% | 2867 fps | 98.9% |
| IMR 4166 Enduron | <<locked>> | 94% | 55,593 psi | 89% | 2848 fps | 95.7% |
| IMR 4198 | <<locked>> | 86% | 55,622 psi | 89% | 2782 fps | 100% |
| IMR 4831ᴾ | <<locked>> | 100% | 42,061 psi | 67% | 2733 fps | 95.9% |
| IMR 4895 | <<locked>> | 94% | 52,765 psi | 85% | 2904 fps | 99.1% |
| IMR 8208 XBR | <<locked>> | 90% | 53,432 psi | 86% | 2851 fps | 99.7% |
| Lovex D073.5 | <<locked>> | 86% | 53,301 psi | 85% | 2838 fps | 99.9% |
| Lovex D073.6 | <<locked>> | 92% | 52,895 psi | 85% | 2871 fps | 100% |
| Lovex S060 | <<locked>> | 92% | 54,578 psi | 88% | 2828 fps | 99.2% |
| Lovex S062 | <<locked>> | 96% | 53,592 psi | 86% | 2864 fps | 99.8% |
| Lovex S065ᴾ | <<locked>> | 100% | 49,530 psi | 79% | 2795 fps | 96% |
| Norma 200 | <<locked>> | 82% | 54,491 psi | 87% | 2789 fps | 100% |
| Norma 201 | <<locked>> | 94% | 56,028 psi | 90% | 2890 fps | 99.9% |
| Norma 202 | <<locked>> | 94% | 56,434 psi | 90% | 2897 fps | 100% |
| Norma 203B | <<locked>> | 96% | 54,186 psi | 87% | 2917 fps | 99.2% |
| Norma URPᴾ | <<locked>> | 100% | 44,222 psi | 71% | 2785 fps | 96.2% |
| Ramshot Big Game | <<locked>> | 96% | 54,636 psi | 88% | 2940 fps | 99.2% |
| Ramshot TAC | <<locked>> | 90% | 54,172 psi | 87% | 2861 fps | 97.2% |
| Ramshot Wild Boar | <<locked>> | 90% | 53,127 psi | 85% | 2884 fps | 99% |
| Ramshot X-Terminator | <<locked>> | 88% | 54,897 psi | 88% | 2854 fps | 99.1% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 34,548 psi | 55% | 1778 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 86% | 53,316 psi | 85% | 2841 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 96% | 53,272 psi | 85% | 2854 fps | 96% |
| ReloadSwiss RS 52 | <<locked>> | 94% | 54,998 psi | 88% | 2995 fps | 99% |
| ReloadSwiss RS 60ᴾ | <<locked>> | 100% | 54,926 psi | 88% | 3028 fps | 100% |
| Rottweil R 901 | <<locked>> | 90% | 53,417 psi | 86% | 2828 fps | 100% |
| Rottweil R 902 | <<locked>> | 96% | 56,318 psi | 90% | 2884 fps | 99.9% |
| Rottweil R 903ᴾ | <<locked>> | 100% | 53,882 psi | 86% | 2904 fps | 99.5% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 49,530 psi | 79% | 2795 fps | 96% |
| Shooters World Match Rifle | <<locked>> | 92% | 52,895 psi | 85% | 2871 fps | 100% |
| Shooters World Precision | <<locked>> | 96% | 53,592 psi | 86% | 2864 fps | 99.8% |
| Shooters World Tactical Rifle | <<locked>> | 84% | 53,011 psi | 85% | 2805 fps | 99.5% |
| SNPE Vectan BA6 1/2 | <<locked>> | 82% | 55,434 psi | 89% | 2513 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 84% | 55,912 psi | 90% | 2887 fps | 100% |
| SNPE Vectan SP 11ᴾ | <<locked>> | 100% | 56,318 psi | 90% | 2972 fps | 99.4% |
| SNPE Vectan SP 3 | <<locked>> | 86% | 55,883 psi | 90% | 2838 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 92% | 55,695 psi | 89% | 2887 fps | 97.9% |
| SNPE Vectan SP 9 | <<locked>> | 94% | 56,043 psi | 90% | 2917 fps | 99.4% |
| SNPE Vectan Tubal 3000 | <<locked>> | 92% | 55,056 psi | 88% | 2792 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 98% | 54,694 psi | 88% | 2789 fps | 100% |
| Somchem S321 | <<locked>> | 88% | 54,636 psi | 88% | 2887 fps | 99.9% |
| Somchem S335 | <<locked>> | 92% | 53,911 psi | 86% | 2789 fps | 100% |
| Somchem S341 | <<locked>> | 92% | 55,201 psi | 89% | 2884 fps | 99.2% |
| Somchem S355ᴾ | <<locked>> | 100% | 54,723 psi | 88% | 2904 fps | 99.5% |
| Somchem S365ᴾ | <<locked>> | 100% | 39,291 psi | 63% | 2730 fps | 98.3% |
| Vihtavuori N120 | <<locked>> | 82% | 56,318 psi | 90% | 2723 fps | 100% |
| Vihtavuori N130 | <<locked>> | 88% | 54,911 psi | 88% | 2766 fps | 100% |
| Vihtavuori N133 | <<locked>> | 92% | 54,940 psi | 88% | 2782 fps | 100% |
| Vihtavuori N135 | <<locked>> | 96% | 55,317 psi | 89% | 2854 fps | 100% |
| Vihtavuori N140 | <<locked>> | 94% | 53,664 psi | 86% | 2828 fps | 100% |
| Vihtavuori N150ᴾ | <<locked>> | 100% | 52,953 psi | 85% | 2841 fps | 99.9% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 46,717 psi | 75% | 2789 fps | 96.7% |
| Vihtavuori N530 | <<locked>> | 90% | 53,882 psi | 86% | 2851 fps | 99.8% |
| Vihtavuori N540 | <<locked>> | 96% | 55,347 psi | 89% | 2874 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 45,803 psi | 73% | 2795 fps | 96.4% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 48,225 psi | 77% | 2782 fps | 98.8% |
| Winchester 748 | <<locked>> | 90% | 53,142 psi | 85% | 2897 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 94% | 55,622 psi | 89% | 2923 fps | 99.6% |
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% | 40,030 psi | 64% | 2575 fps | 100% |
| Accurate 2200 | <<locked>> | 80% | 51,793 psi | 83% | 2844 fps | 98.2% |
| Accurate 2230 | <<locked>> | 80% | 52,228 psi | 84% | 2854 fps | 98.6% |
| Accurate 2460 | <<locked>> | 80% | 43,337 psi | 69% | 2667 fps | 99.7% |
| Accurate 2495 | <<locked>> | 80% | 31,981 psi | 51% | 2464 fps | 99.8% |
| Accurate 2520 | <<locked>> | 80% | 38,566 psi | 62% | 2615 fps | 99% |
| Accurate 4064 | <<locked>> | 80% | 30,269 psi | 49% | 2438 fps | 97.8% |
| Accurate 4350 | <<locked>> | 98% | 40,727 psi | 65% | 2726 fps | 95.4% |
| Accurate LT-30 | <<locked>> | 80% | 48,747 psi | 78% | 2664 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 49,153 psi | 79% | 2684 fps | 99.9% |
| ADI AR 2206H | <<locked>> | 80% | 36,796 psi | 59% | 2566 fps | 95.6% |
| ADI AR 2207 | <<locked>> | 80% | 53,171 psi | 85% | 2733 fps | 100% |
| ADI AR 2208 | <<locked>> | 86% | 37,956 psi | 61% | 2572 fps | 95.1% |
| ADI AR 2219 | <<locked>> | 80% | 48,588 psi | 78% | 2772 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 80% | 38,870 psi | 62% | 2589 fps | 97.5% |
| Alliant AR-Comp | <<locked>> | 80% | 37,492 psi | 60% | 2595 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 44,918 psi | 72% | 2785 fps | 98.3% |
| Alliant Power Pro 2000-MR | 60.8 gr | 86% | 40,756 psi | 65% | 2746 fps | 95.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 32,155 psi | 52% | 2480 fps | 95% |
| Alliant Reloder-10x | <<locked>> | 80% | 45,585 psi | 73% | 2680 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 37,275 psi | 60% | 2598 fps | 95.1% |
| Alliant Reloder-16 | <<locked>> | 98% | 41,669 psi | 67% | 2743 fps | 95.6% |
| Alliant Reloder-17 | <<locked>> | 90% | 36,506 psi | 59% | 2654 fps | 95.7% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 47,645 psi | 76% | 2657 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 84% | 41,046 psi | 66% | 2674 fps | 95.6% |
| Bofors RP3 | <<locked>> | 84% | 33,518 psi | 54% | 2526 fps | 95.7% |
| Hodgdon Benchmark | <<locked>> | 80% | 41,031 psi | 66% | 2592 fps | 98.5% |
| Hodgdon BL-C2 | <<locked>> | 80% | 36,666 psi | 59% | 2592 fps | 97.6% |
| Hodgdon CFE223 | 57.8 gr | 80% | 40,408 psi | 65% | 2720 fps | 96.1% |
| Hodgdon H322 | <<locked>> | 80% | 44,309 psi | 71% | 2703 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 45,034 psi | 72% | 2723 fps | 99.9% |
| Hodgdon H380 | <<locked>> | 90% | 42,917 psi | 69% | 2703 fps | 95.4% |
| Hodgdon H4895 | <<locked>> | 80% | 37,057 psi | 59% | 2579 fps | 96.3% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 35,534 psi | 57% | 2575 fps | 95.5% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 32,953 psi | 53% | 2530 fps | 95.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,411 psi | 41% | 1552 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 35,752 psi | 57% | 2533 fps | 95.8% |
| IMR 3031 | <<locked>> | 80% | 35,824 psi | 57% | 2589 fps | 99.8% |
| IMR 4064 | <<locked>> | 84% | 37,333 psi | 60% | 2556 fps | 95.2% |
| IMR 4166 Enduron | <<locked>> | 92% | 52,054 psi | 83% | 2792 fps | 95% |
| IMR 4198 | <<locked>> | 80% | 46,456 psi | 74% | 2651 fps | 100% |
| IMR 4831 | <<locked>> | 98% | 39,392 psi | 63% | 2677 fps | 95.1% |
| IMR 4895 | <<locked>> | 82% | 35,752 psi | 57% | 2575 fps | 95.3% |
| IMR 8208 XBR | <<locked>> | 80% | 38,870 psi | 62% | 2589 fps | 97.5% |
| Lovex D073.5 | <<locked>> | 80% | 43,120 psi | 69% | 2671 fps | 99.1% |
| Lovex D073.6 | <<locked>> | 80% | 34,838 psi | 56% | 2543 fps | 98.1% |
| Lovex S060 | <<locked>> | 80% | 37,623 psi | 60% | 2516 fps | 95.9% |
| Lovex S062 | <<locked>> | 80% | 32,256 psi | 52% | 2451 fps | 95.6% |
| Lovex S065 | <<locked>> | 98% | 46,557 psi | 75% | 2743 fps | 95.3% |
| Norma 200 | <<locked>> | 80% | 51,126 psi | 82% | 2740 fps | 100% |
| Norma 201 | <<locked>> | 80% | 35,824 psi | 57% | 2523 fps | 96.8% |
| Norma 202 | <<locked>> | 80% | 35,969 psi | 58% | 2543 fps | 98.9% |
| Norma 203B | <<locked>> | 84% | 36,550 psi | 59% | 2585 fps | 95.6% |
| Norma URP | <<locked>> | 98% | 41,481 psi | 67% | 2730 fps | 95.4% |
| Ramshot Big Game | <<locked>> | 84% | 36,187 psi | 58% | 2592 fps | 95% |
| Ramshot TAC | <<locked>> | 86% | 47,355 psi | 76% | 2746 fps | 95.7% |
| Ramshot Wild Boar | <<locked>> | 80% | 37,724 psi | 60% | 2595 fps | 95.8% |
| Ramshot X-Terminator | <<locked>> | 80% | 42,061 psi | 67% | 2631 fps | 96.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 25,454 psi | 41% | 1588 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 43,656 psi | 70% | 2680 fps | 99.4% |
| ReloadSwiss RS 50 | <<locked>> | 94% | 50,053 psi | 80% | 2802 fps | 95.3% |
| ReloadSwiss RS 52 | 57.5 gr | 84% | 38,609 psi | 62% | 2694 fps | 95.5% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 29,776 psi | 48% | 2480 fps | 95.2% |
| Rottweil R 901 | <<locked>> | 80% | 39,392 psi | 63% | 2582 fps | 99.3% |
| Rottweil R 902 | <<locked>> | 80% | 34,142 psi | 55% | 2477 fps | 96.2% |
| Rottweil R 903 | <<locked>> | 86% | 33,634 psi | 54% | 2523 fps | 95.4% |
| Shooters World Long Rifle | <<locked>> | 98% | 46,557 psi | 75% | 2743 fps | 95.3% |
| Shooters World Match Rifle | <<locked>> | 80% | 34,838 psi | 56% | 2543 fps | 98.1% |
| Shooters World Precision | <<locked>> | 80% | 32,256 psi | 52% | 2451 fps | 95.6% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 46,195 psi | 74% | 2694 fps | 98.7% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 52,576 psi | 84% | 2477 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 80% | 48,936 psi | 78% | 2782 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 37,811 psi | 61% | 2638 fps | 95.7% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 46,398 psi | 74% | 2697 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 86% | 45,034 psi | 72% | 2713 fps | 95.8% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 35,375 psi | 57% | 2533 fps | 95% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 37,768 psi | 61% | 2503 fps | 99.1% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 30,835 psi | 49% | 2362 fps | 98.5% |
| Somchem S321 | <<locked>> | 80% | 41,524 psi | 67% | 2664 fps | 98.4% |
| Somchem S335 | <<locked>> | 80% | 37,101 psi | 59% | 2503 fps | 99.5% |
| Somchem S341 | <<locked>> | 80% | 36,303 psi | 58% | 2543 fps | 95.3% |
| Somchem S355 | <<locked>> | 86% | 34,896 psi | 56% | 2536 fps | 95.5% |
| Somchem S365 | <<locked>> | 94% | 32,256 psi | 52% | 2556 fps | 95.8% |
| Vihtavuori N120 | <<locked>> | 80% | 53,084 psi | 85% | 2680 fps | 100% |
| Vihtavuori N130 | <<locked>> | 80% | 42,960 psi | 69% | 2585 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 37,898 psi | 61% | 2510 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 32,967 psi | 53% | 2477 fps | 99.8% |
| Vihtavuori N140 | <<locked>> | 80% | 34,040 psi | 55% | 2480 fps | 98.8% |
| Vihtavuori N150 | <<locked>> | 84% | 31,082 psi | 50% | 2425 fps | 95.7% |
| Vihtavuori N160 | <<locked>> | 96% | 41,031 psi | 66% | 2680 fps | 95.1% |
| Vihtavuori N530 | <<locked>> | 80% | 38,566 psi | 62% | 2579 fps | 97.6% |
| Vihtavuori N540 | <<locked>> | 80% | 32,605 psi | 52% | 2457 fps | 97.9% |
| Vihtavuori N550 | <<locked>> | 98% | 42,699 psi | 68% | 2733 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 36,854 psi | 59% | 2559 fps | 96% |
| Winchester 748 | <<locked>> | 80% | 37,434 psi | 60% | 2615 fps | 98.1% |
| Winchester StaBALL Match | <<locked>> | 80% | 34,330 psi | 55% | 2530 fps | 95.4% |
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 96 powders for .338 Win Mag. loaded with the .338 | 185gr | Hornady CX. ReloadSwiss RS 60 delivers the highest muzzle velocity at 3,028 fps; across all powders the maximum-charge window runs from 1,736 fps to 3,028 fps. Accurate 4350 gives the best case fill at 100 %, and 96 of the 96 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 185.0 gr projectile in 0.338" calls for a 1:12.5 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, Hodgdon CFE223, ReloadSwiss RS 52 rank at the top here: for .338 Win Mag. with the .338 | 185gr | Hornady CX 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.