Load Specifications
Load data in caliber .300 Rem. SA Ultra Mag. with .308 | 150gr | Barnes RRLP 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, ReloadSwiss RS 52 and ReloadSwiss RS 60.
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>> | 88% | 55,230 psi | 85% | 2874 fps | 100% |
| Accurate 2460 | <<locked>> | 86% | 57,377 psi | 88% | 2953 fps | 100% |
| Accurate 2495 | <<locked>> | 94% | 56,550 psi | 87% | 2940 fps | 100% |
| Accurate 2520 | <<locked>> | 88% | 55,506 psi | 85% | 2963 fps | 100% |
| Accurate 4064 | <<locked>> | 96% | 56,362 psi | 87% | 2982 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 48,559 psi | 75% | 2933 fps | 97.7% |
| Accurate LT-30 | <<locked>> | 84% | 58,102 psi | 89% | 2867 fps | 100% |
| Accurate LT-32 | <<locked>> | 84% | 58,566 psi | 90% | 2894 fps | 100% |
| ADI AR 2206H | <<locked>> | 92% | 57,769 psi | 89% | 3018 fps | 99.7% |
| ADI AR 2208 | <<locked>> | 98% | 58,813 psi | 90% | 3012 fps | 99.4% |
| ADI AR 2219 | <<locked>> | 82% | 55,506 psi | 85% | 2943 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 90% | 57,145 psi | 88% | 2976 fps | 100% |
| Alliant AR-Comp | <<locked>> | 90% | 57,072 psi | 88% | 2953 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 84% | 55,056 psi | 85% | 3031 fps | 99.7% |
| Alliant Power Pro 2000-MR | <<locked>> | 94% | 57,464 psi | 88% | 3136 fps | 99.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 98% | 58,117 psi | 89% | 3031 fps | 99.9% |
| Alliant Reloder-10x | <<locked>> | 86% | 58,668 psi | 90% | 2933 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 94% | 55,506 psi | 85% | 3005 fps | 99.3% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 47,732 psi | 73% | 2936 fps | 97.8% |
| Alliant Reloder-17ᴾ | <<locked>> | 100% | 55,405 psi | 85% | 3100 fps | 99.8% |
| Baschieri & Pellagri 106 | <<locked>> | 84% | 57,537 psi | 89% | 2864 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 92% | 57,986 psi | 89% | 3035 fps | 99.2% |
| Bofors RP3 | <<locked>> | 96% | 55,259 psi | 85% | 2999 fps | 99.9% |
| Hodgdon Benchmark | <<locked>> | 88% | 55,695 psi | 86% | 2910 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 90% | 56,144 psi | 86% | 3005 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 88% | 58,378 psi | 90% | 3110 fps | 99.5% |
| Hodgdon H322 | <<locked>> | 86% | 58,044 psi | 89% | 2979 fps | 100% |
| Hodgdon H335 | <<locked>> | 84% | 55,347 psi | 85% | 2949 fps | 100% |
| Hodgdon H380 | <<locked>> | 96% | 56,681 psi | 87% | 3009 fps | 98.5% |
| Hodgdon H4895 | <<locked>> | 92% | 58,276 psi | 90% | 3031 fps | 99.9% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 43,816 psi | 67% | 2815 fps | 98.3% |
| Hodgdon LEVERevolution | <<locked>> | 94% | 57,406 psi | 88% | 3064 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 34,722 psi | 53% | 1798 fps | 100% |
| Hodgdon VARGET | <<locked>> | 92% | 56,391 psi | 87% | 2982 fps | 99.8% |
| IMR 3031 | <<locked>> | 92% | 57,783 psi | 89% | 3018 fps | 100% |
| IMR 4064 | <<locked>> | 96% | 58,204 psi | 90% | 2995 fps | 99.5% |
| IMR 4166 Enduron | <<locked>> | 92% | 55,521 psi | 85% | 2920 fps | 96.2% |
| IMR 4198 | <<locked>> | 86% | 58,697 psi | 90% | 2890 fps | 100% |
| IMR 4451 Enduronᴾ | <<locked>> | 100% | 57,885 psi | 89% | 2989 fps | 96.6% |
| IMR 4831ᴾ | <<locked>> | 100% | 46,209 psi | 71% | 2874 fps | 97.4% |
| IMR 4895 | <<locked>> | 94% | 56,884 psi | 88% | 3038 fps | 99.7% |
| IMR 8208 XBR | <<locked>> | 90% | 57,145 psi | 88% | 2976 fps | 100% |
| Lovex D073.5 | <<locked>> | 86% | 57,522 psi | 88% | 2963 fps | 100% |
| Lovex D073.6 | <<locked>> | 92% | 57,348 psi | 88% | 2999 fps | 100% |
| Lovex S060 | <<locked>> | 92% | 57,899 psi | 89% | 2949 fps | 99.7% |
| Lovex S062 | <<locked>> | 96% | 57,885 psi | 89% | 2995 fps | 100% |
| Lovex S065ᴾ | <<locked>> | 100% | 53,476 psi | 82% | 2930 fps | 97.3% |
| Norma 200 | <<locked>> | 82% | 58,421 psi | 90% | 2904 fps | 100% |
| Norma 201 | <<locked>> | 92% | 56,666 psi | 87% | 2966 fps | 100% |
| Norma 202 | <<locked>> | 92% | 57,101 psi | 88% | 2972 fps | 100% |
| Norma 203B | <<locked>> | 96% | 58,262 psi | 90% | 3045 fps | 99.7% |
| Norma URPᴾ | <<locked>> | 100% | 48,124 psi | 74% | 2923 fps | 97.6% |
| Ramshot Big Game | <<locked>> | 94% | 55,114 psi | 85% | 3015 fps | 99.4% |
| Ramshot TAC | <<locked>> | 90% | 57,798 psi | 89% | 2989 fps | 98.1% |
| Ramshot Wild Boar | <<locked>> | 90% | 57,000 psi | 88% | 3009 fps | 99.6% |
| Ramshot X-Terminator | <<locked>> | 88% | 58,552 psi | 90% | 2979 fps | 99.6% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,114 psi | 54% | 1841 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 86% | 56,811 psi | 87% | 2959 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 96% | 57,435 psi | 88% | 2989 fps | 97.3% |
| ReloadSwiss RS 52 | <<locked>> | 92% | 55,608 psi | 86% | 3071 fps | 99.3% |
| ReloadSwiss RS 60 | <<locked>> | 98% | 55,376 psi | 85% | 3107 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 48,182 psi | 74% | 2953 fps | 97.4% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 49,081 psi | 76% | 2972 fps | 96.8% |
| Rottweil R 901 | <<locked>> | 90% | 57,464 psi | 88% | 2949 fps | 100% |
| Rottweil R 902 | <<locked>> | 94% | 56,797 psi | 87% | 2959 fps | 100% |
| Rottweil R 903ᴾ | <<locked>> | 100% | 58,624 psi | 90% | 3038 fps | 99.9% |
| Shooters World Long Rifleᴾ | <<locked>> | 100% | 53,476 psi | 82% | 2930 fps | 97.3% |
| Shooters World Match Rifle | <<locked>> | 92% | 57,348 psi | 88% | 2999 fps | 100% |
| Shooters World Precision | <<locked>> | 96% | 57,885 psi | 89% | 2995 fps | 100% |
| Shooters World Tactical Rifle | <<locked>> | 84% | 56,840 psi | 87% | 2930 fps | 99.9% |
| SNPE Vectan BA6 1/2 | <<locked>> | 82% | 57,943 psi | 89% | 2605 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 82% | 56,101 psi | 86% | 2956 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 98% | 57,029 psi | 88% | 3051 fps | 99.6% |
| SNPE Vectan SP 3 | <<locked>> | 84% | 55,883 psi | 86% | 2904 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 90% | 55,811 psi | 86% | 2963 fps | 98.3% |
| SNPE Vectan SP 9 | <<locked>> | 92% | 56,246 psi | 87% | 2989 fps | 99.6% |
| SNPE Vectan Tubal 3000 | <<locked>> | 92% | 58,639 psi | 90% | 2910 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 98% | 58,218 psi | 90% | 2900 fps | 100% |
| SNPE Vectan Tubal 7000ᴾ | <<locked>> | 100% | 54,099 psi | 83% | 2881 fps | 95.9% |
| Somchem S321 | <<locked>> | 88% | 58,595 psi | 90% | 3012 fps | 100% |
| Somchem S335 | <<locked>> | 92% | 57,740 psi | 89% | 2907 fps | 100% |
| Somchem S341 | <<locked>> | 90% | 55,317 psi | 85% | 2956 fps | 99.4% |
| Somchem S355 | <<locked>> | 98% | 55,390 psi | 85% | 2986 fps | 99.7% |
| Somchem S365ᴾ | <<locked>> | 100% | 42,844 psi | 66% | 2871 fps | 99.3% |
| Vihtavuori N130 | <<locked>> | 88% | 58,378 psi | 90% | 2877 fps | 100% |
| Vihtavuori N133 | <<locked>> | 92% | 58,523 psi | 90% | 2894 fps | 100% |
| Vihtavuori N135 | <<locked>> | 94% | 56,072 psi | 86% | 2927 fps | 100% |
| Vihtavuori N140 | <<locked>> | 94% | 57,479 psi | 88% | 2946 fps | 100% |
| Vihtavuori N150ᴾ | <<locked>> | 100% | 57,159 psi | 88% | 2966 fps | 100% |
| Vihtavuori N160ᴾ | <<locked>> | 100% | 50,879 psi | 78% | 2930 fps | 98% |
| Vihtavuori N530 | <<locked>> | 90% | 57,682 psi | 89% | 2976 fps | 100% |
| Vihtavuori N540 | <<locked>> | 94% | 55,593 psi | 86% | 2940 fps | 100% |
| Vihtavuori N550ᴾ | <<locked>> | 100% | 49,705 psi | 76% | 2927 fps | 97.6% |
| Winchester 6.5 StaBALLᴾ | <<locked>> | 100% | 51,808 psi | 80% | 2913 fps | 99.5% |
| Winchester 748 | <<locked>> | 90% | 57,043 psi | 88% | 3022 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 92% | 56,115 psi | 86% | 2999 fps | 99.8% |
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% | 43,105 psi | 66% | 2687 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 46,963 psi | 72% | 2792 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 35,810 psi | 55% | 2598 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 42,105 psi | 65% | 2743 fps | 99.6% |
| Accurate 4064 | <<locked>> | 80% | 33,866 psi | 52% | 2579 fps | 99% |
| Accurate 4350 | <<locked>> | 94% | 39,131 psi | 60% | 2753 fps | 95.3% |
| Accurate LT-30 | <<locked>> | 80% | 51,343 psi | 79% | 2772 fps | 100% |
| Accurate LT-32 | <<locked>> | 80% | 51,735 psi | 80% | 2795 fps | 100% |
| ADI AR 2206H | <<locked>> | 80% | 39,726 psi | 61% | 2694 fps | 96.9% |
| ADI AR 2208 | <<locked>> | 84% | 38,319 psi | 59% | 2641 fps | 95.6% |
| ADI AR 2219 | <<locked>> | 80% | 51,938 psi | 80% | 2890 fps | 100% |
| ADI Benchmark 8208 | <<locked>> | 80% | 41,713 psi | 64% | 2710 fps | 98.5% |
| Alliant AR-Comp | <<locked>> | 80% | 40,857 psi | 63% | 2713 fps | 100% |
| Alliant Power Pro 1200-R | <<locked>> | 80% | 48,385 psi | 74% | 2917 fps | 99.1% |
| Alliant Power Pro 2000-MR | 51.4 gr | 82% | 38,276 psi | 59% | 2756 fps | 95.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 32,953 psi | 51% | 2552 fps | 95.7% |
| Alliant Reloder-10x | <<locked>> | 80% | 48,704 psi | 75% | 2789 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 38,029 psi | 59% | 2674 fps | 95.8% |
| Alliant Reloder-16 | <<locked>> | 94% | 39,798 psi | 61% | 2769 fps | 95.5% |
| Alliant Reloder-17 | <<locked>> | 86% | 34,780 psi | 54% | 2674 fps | 95.5% |
| Baschieri & Pellagri 106 | <<locked>> | 80% | 50,676 psi | 78% | 2769 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 38,682 psi | 60% | 2687 fps | 95.3% |
| Bofors RP3 | <<locked>> | 80% | 32,314 psi | 50% | 2549 fps | 95.6% |
| Hodgdon Benchmark | <<locked>> | 80% | 43,787 psi | 67% | 2707 fps | 99.2% |
| Hodgdon BL-C2 | <<locked>> | 80% | 40,103 psi | 62% | 2726 fps | 98.7% |
| Hodgdon CFE223 | <<locked>> | 80% | 43,801 psi | 67% | 2854 fps | 97.4% |
| Hodgdon H322 | <<locked>> | 80% | 47,456 psi | 73% | 2822 fps | 100% |
| Hodgdon H335 | <<locked>> | 80% | 48,356 psi | 74% | 2841 fps | 100% |
| Hodgdon H380 | <<locked>> | 86% | 40,712 psi | 63% | 2723 fps | 95.1% |
| Hodgdon H4895 | <<locked>> | 80% | 40,001 psi | 62% | 2707 fps | 97.5% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 34,156 psi | 53% | 2602 fps | 95.4% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 35,882 psi | 55% | 2664 fps | 96.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 25,933 psi | 40% | 1611 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 38,406 psi | 59% | 2654 fps | 97% |
| IMR 3031 | <<locked>> | 80% | 39,030 psi | 60% | 2713 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 37,637 psi | 58% | 2621 fps | 95.7% |
| IMR 4166 Enduron | <<locked>> | 90% | 52,127 psi | 80% | 2864 fps | 95.5% |
| IMR 4198 | <<locked>> | 80% | 49,153 psi | 76% | 2756 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 96% | 51,271 psi | 79% | 2881 fps | 95.2% |
| IMR 4831 | <<locked>> | 94% | 37,971 psi | 58% | 2707 fps | 95% |
| IMR 4895 | <<locked>> | 80% | 36,405 psi | 56% | 2648 fps | 95.9% |
| IMR 8208 XBR | <<locked>> | 80% | 41,713 psi | 64% | 2710 fps | 98.5% |
| Lovex D073.5 | <<locked>> | 80% | 46,833 psi | 72% | 2795 fps | 99.7% |
| Lovex D073.6 | <<locked>> | 80% | 38,174 psi | 59% | 2671 fps | 99.1% |
| Lovex S060 | <<locked>> | 80% | 40,263 psi | 62% | 2638 fps | 97% |
| Lovex S062 | <<locked>> | 80% | 35,186 psi | 54% | 2579 fps | 97% |
| Lovex S065 | <<locked>> | 94% | 44,411 psi | 68% | 2766 fps | 95.2% |
| Norma 200 | <<locked>> | 80% | 55,042 psi | 85% | 2858 fps | 100% |
| Norma 201 | <<locked>> | 80% | 39,015 psi | 60% | 2651 fps | 98% |
| Norma 202 | <<locked>> | 80% | 38,957 psi | 60% | 2664 fps | 99.5% |
| Norma 203B | <<locked>> | 80% | 34,983 psi | 54% | 2605 fps | 95.4% |
| Norma URP | <<locked>> | 94% | 39,624 psi | 61% | 2753 fps | 95.3% |
| Ramshot Big Game | <<locked>> | 82% | 36,767 psi | 57% | 2667 fps | 95.7% |
| Ramshot TAC | <<locked>> | 82% | 44,396 psi | 68% | 2756 fps | 95.4% |
| Ramshot Wild Boar | <<locked>> | 80% | 40,741 psi | 63% | 2723 fps | 97.1% |
| Ramshot X-Terminator | <<locked>> | 80% | 45,281 psi | 70% | 2759 fps | 98% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,165 psi | 40% | 1647 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 46,760 psi | 72% | 2799 fps | 99.8% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 47,210 psi | 73% | 2818 fps | 95.1% |
| ReloadSwiss RS 52 | 48.6 gr | 80% | 36,666 psi | 56% | 2707 fps | 95.2% |
| ReloadSwiss RS 60 | 49.4 gr | 80% | 30,414 psi | 47% | 2562 fps | 96.2% |
| ReloadSwiss RS 62 | <<locked>> | 96% | 41,930 psi | 65% | 2828 fps | 95.8% |
| ReloadSwiss RS 70 | <<locked>> | 98% | 45,759 psi | 70% | 2904 fps | 95.9% |
| Rottweil R 901 | <<locked>> | 80% | 42,627 psi | 66% | 2703 fps | 99.8% |
| Rottweil R 902 | <<locked>> | 80% | 37,043 psi | 57% | 2598 fps | 97.4% |
| Rottweil R 903 | <<locked>> | 82% | 32,430 psi | 50% | 2546 fps | 95.3% |
| Shooters World Long Rifle | <<locked>> | 94% | 44,411 psi | 68% | 2766 fps | 95.2% |
| Shooters World Match Rifle | <<locked>> | 80% | 38,174 psi | 59% | 2671 fps | 99.1% |
| Shooters World Precision | <<locked>> | 80% | 35,186 psi | 54% | 2579 fps | 97% |
| Shooters World Tactical Rifle | <<locked>> | 80% | 49,603 psi | 76% | 2818 fps | 99.4% |
| SNPE Vectan BA6 1/2 | <<locked>> | 80% | 54,940 psi | 85% | 2569 fps | 100% |
| SNPE Vectan SP 10 | <<locked>> | 80% | 52,388 psi | 81% | 2900 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 35,868 psi | 55% | 2651 fps | 95.5% |
| SNPE Vectan SP 3 | <<locked>> | 80% | 49,429 psi | 76% | 2808 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 42,511 psi | 65% | 2726 fps | 95.5% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 38,189 psi | 59% | 2654 fps | 96.4% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 40,437 psi | 62% | 2615 fps | 99.7% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 33,301 psi | 51% | 2474 fps | 99.3% |
| SNPE Vectan Tubal 7000 | <<locked>> | 98% | 50,531 psi | 78% | 2825 fps | 95.1% |
| Somchem S321 | <<locked>> | 80% | 44,918 psi | 69% | 2792 fps | 99.2% |
| Somchem S335 | <<locked>> | 80% | 40,103 psi | 62% | 2621 fps | 99.9% |
| Somchem S341 | <<locked>> | 80% | 39,392 psi | 61% | 2671 fps | 96.7% |
| Somchem S355 | <<locked>> | 82% | 33,533 psi | 52% | 2559 fps | 95.4% |
| Somchem S365 | <<locked>> | 90% | 31,198 psi | 48% | 2585 fps | 95.8% |
| Vihtavuori N130 | <<locked>> | 80% | 45,803 psi | 70% | 2694 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 40,596 psi | 62% | 2618 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 35,940 psi | 55% | 2592 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 36,927 psi | 57% | 2598 fps | 99.5% |
| Vihtavuori N150 | <<locked>> | 80% | 29,878 psi | 46% | 2444 fps | 95.6% |
| Vihtavuori N160 | <<locked>> | 94% | 41,669 psi | 64% | 2759 fps | 95.8% |
| Vihtavuori N530 | <<locked>> | 80% | 41,669 psi | 64% | 2703 fps | 98.5% |
| Vihtavuori N540 | <<locked>> | 80% | 35,476 psi | 55% | 2582 fps | 98.9% |
| Vihtavuori N550 | <<locked>> | 94% | 40,857 psi | 63% | 2759 fps | 95.4% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 34,766 psi | 53% | 2572 fps | 95.7% |
| Winchester 748 | <<locked>> | 80% | 40,799 psi | 63% | 2746 fps | 99% |
| Winchester StaBALL Match | <<locked>> | 80% | 37,333 psi | 57% | 2654 fps | 96.8% |
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 .300 Rem. SA Ultra Mag. loaded with the .308 | 150gr | Barnes RRLP. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,136 fps; across all powders the maximum-charge window runs from 1,798 fps to 3,136 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 (448 MPa), the top charges use 53–90 %, leaving at least 10 % headroom. The 150.0 gr projectile in 0.308" calls for a 1:11.0 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, ReloadSwiss RS 60 rank at the top here: for .300 Rem. SA Ultra Mag. with the .308 | 150gr | Barnes RRLP 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.