Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 180gr | Hornady SST InterLock bullet and 71 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon Retumbo, ReloadSwiss RS 76 and Vihtavuori N560.
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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Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 90% | 55,970 psi | 86% | 2815 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 56,304 psi | 87% | 2841 fps | 100% |
| Accurate High Country | <<locked>> | 88% | 57,783 psi | 89% | 2969 fps | 99.7% |
| Accurate MAGPRO | <<locked>> | 88% | 54,810 psi | 84% | 2910 fps | 98.7% |
| ADI AR 2209 | <<locked>> | 88% | 57,406 psi | 88% | 2904 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 90% | 55,608 psi | 86% | 2910 fps | 99.4% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 57,972 psi | 89% | 2936 fps | 99.8% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 52,402 psi | 81% | 2897 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 57,537 psi | 89% | 2900 fps | 99.9% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 57,537 psi | 89% | 2900 fps | 99.9% |
| Alliant Reloder-16 | <<locked>> | 84% | 57,493 psi | 88% | 2897 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 56,884 psi | 88% | 2890 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 90% | 55,970 psi | 86% | 2907 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 92% | 57,609 psi | 89% | 2871 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 57,682 psi | 89% | 2936 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 58,639 psi | 90% | 2959 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 55,767 psi | 86% | 2956 fps | 97.5% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 56,550 psi | 87% | 2867 fps | 97.7% |
| Bofors RP15 | <<locked>> | 92% | 55,158 psi | 85% | 2894 fps | 99.8% |
| Bofors RP30 | <<locked>> | 98% | 57,609 psi | 89% | 2949 fps | 99.8% |
| Bofors RP5 | <<locked>> | 90% | 55,970 psi | 86% | 2907 fps | 99.9% |
| Bofors RP7 | <<locked>> | 82% | 57,624 psi | 89% | 2841 fps | 100% |
| Hodgdon H1000 | <<locked>> | 96% | 55,666 psi | 86% | 2904 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 82% | 57,740 psi | 89% | 2894 fps | 100% |
| Hodgdon H4831 | <<locked>> | 88% | 55,100 psi | 85% | 2851 fps | 98.9% |
| Hodgdon H4831 SC | <<locked>> | 90% | 57,754 psi | 89% | 2887 fps | 99.2% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 57,754 psi | 89% | 2818 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 56,608 psi | 87% | 3018 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,391 psi | 58% | 1850 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 56,260 psi | 87% | 2828 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 56,739 psi | 87% | 2831 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 55,695 psi | 86% | 2831 fps | 99.1% |
| IMR 7828 SSC | <<locked>> | 92% | 57,667 psi | 89% | 2949 fps | 99.6% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 47,921 psi | 74% | 2812 fps | 98.7% |
| Lovex S065 | <<locked>> | 82% | 56,463 psi | 87% | 2808 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 58,523 psi | 90% | 2858 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 57,435 psi | 88% | 2835 fps | 100% |
| Norma 204 | <<locked>> | 84% | 57,595 psi | 89% | 2884 fps | 99.9% |
| Norma 217ᴾ | <<locked>> | 100% | 48,559 psi | 75% | 2835 fps | 99.9% |
| Norma MRP | <<locked>> | 88% | 56,043 psi | 86% | 2923 fps | 100% |
| Norma URP | <<locked>> | 84% | 58,421 psi | 90% | 2877 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 54,752 psi | 84% | 2910 fps | 99.6% |
| Ramshot Hunter | <<locked>> | 84% | 57,479 psi | 88% | 2881 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 57,653 psi | 89% | 2900 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,276 psi | 59% | 1893 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 56,652 psi | 87% | 2861 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 55,114 psi | 85% | 2887 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 57,798 psi | 89% | 3009 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 57,246 psi | 88% | 2969 fps | 99.2% |
| Rottweil R 904 | <<locked>> | 88% | 58,146 psi | 89% | 2871 fps | 99.6% |
| Rottweil R 905 | <<locked>> | 88% | 56,608 psi | 87% | 2881 fps | 99.9% |
| Rottweil R 907 | <<locked>> | 82% | 57,624 psi | 89% | 2841 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 82% | 56,463 psi | 87% | 2808 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 58,523 psi | 90% | 2858 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 55,434 psi | 85% | 2762 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 56,202 psi | 86% | 2881 fps | 99.9% |
| Somchem S361 | <<locked>> | 86% | 56,057 psi | 86% | 2805 fps | 99% |
| Somchem S365 | <<locked>> | 84% | 55,825 psi | 86% | 2825 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 57,029 psi | 88% | 2854 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 56,086 psi | 86% | 2812 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 57,014 psi | 88% | 2835 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 55,492 psi | 85% | 2818 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 55,825 psi | 86% | 2851 fps | 100% |
| Vihtavuori N560 | <<locked>> | 88% | 55,608 psi | 86% | 2923 fps | 99.2% |
| Vihtavuori N565 | <<locked>> | 94% | 56,289 psi | 87% | 2910 fps | 99.4% |
| Vihtavuori N568 | <<locked>> | 98% | 57,653 psi | 89% | 2969 fps | 98.9% |
| Vihtavuori N570 | <<locked>> | 98% | 54,636 psi | 84% | 2966 fps | 96.9% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 55,898 psi | 86% | 2766 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 57,943 psi | 89% | 2897 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 57,276 psi | 88% | 2959 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 57,014 psi | 88% | 2848 fps | 99.9% |
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 3100 | <<locked>> | 80% | 39,856 psi | 61% | 2552 fps | 99.3% |
| Accurate 4350 | <<locked>> | 80% | 52,721 psi | 81% | 2792 fps | 100% |
| Accurate High Country | <<locked>> | 80% | 43,439 psi | 67% | 2723 fps | 97.3% |
| Accurate MAGPRO | <<locked>> | 80% | 41,104 psi | 63% | 2661 fps | 95.3% |
| ADI AR 2209 | <<locked>> | 80% | 43,787 psi | 67% | 2677 fps | 98.3% |
| ADI AR 2213 | <<locked>> | 80% | 39,204 psi | 60% | 2612 fps | 95.8% |
| ADI AR 2217 | <<locked>> | 88% | 38,363 psi | 59% | 2589 fps | 96% |
| ADI AR 2225 | <<locked>> | 84% | 30,414 psi | 47% | 2428 fps | 95.7% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 44,208 psi | 68% | 2677 fps | 98.4% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 44,208 psi | 68% | 2677 fps | 98.4% |
| Alliant Reloder-16 | <<locked>> | 80% | 50,198 psi | 77% | 2792 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 43,787 psi | 67% | 2671 fps | 98.3% |
| Alliant Reloder-22 | <<locked>> | 80% | 39,769 psi | 61% | 2621 fps | 97.4% |
| Alliant Reloder-23 | <<locked>> | 80% | 38,493 psi | 59% | 2575 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 33,214 psi | 51% | 2500 fps | 98.5% |
| Alliant Reloder-26 | <<locked>> | 80% | 43,250 psi | 67% | 2726 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 96% | 47,877 psi | 74% | 2825 fps | 95.5% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 46,760 psi | 72% | 2700 fps | 95.2% |
| Bofors RP15 | <<locked>> | 80% | 36,999 psi | 57% | 2559 fps | 96.3% |
| Bofors RP30 | <<locked>> | 84% | 35,360 psi | 54% | 2543 fps | 95.1% |
| Bofors RP5 | <<locked>> | 80% | 39,769 psi | 61% | 2621 fps | 97.4% |
| Bofors RP7 | <<locked>> | 80% | 54,128 psi | 83% | 2789 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 84% | 36,448 psi | 56% | 2546 fps | 95.9% |
| Hodgdon H414 | <<locked>> | 80% | 54,041 psi | 83% | 2841 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 41,800 psi | 64% | 2618 fps | 96.1% |
| Hodgdon H4831 SC | <<locked>> | 80% | 41,017 psi | 63% | 2602 fps | 95.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 47,427 psi | 73% | 2674 fps | 100% |
| Hodgdon Retumbo | 75 gr | 80% | 32,430 psi | 50% | 2520 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,007 psi | 43% | 1660 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 49,530 psi | 76% | 2726 fps | 99.7% |
| IMR 4831 | <<locked>> | 80% | 49,748 psi | 77% | 2733 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 43,105 psi | 66% | 2615 fps | 96.6% |
| IMR 7828 SSC | <<locked>> | 80% | 37,855 psi | 58% | 2592 fps | 95.4% |
| IMR 8133 Enduron | <<locked>> | 92% | 36,274 psi | 56% | 2579 fps | 95.3% |
| Lovex S065 | <<locked>> | 80% | 53,113 psi | 82% | 2762 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 51,561 psi | 79% | 2759 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 34,185 psi | 53% | 2431 fps | 98% |
| Norma 204 | <<locked>> | 80% | 50,125 psi | 77% | 2769 fps | 99.2% |
| Norma 217 | <<locked>> | 88% | 31,763 psi | 49% | 2487 fps | 95.7% |
| Norma MRP | <<locked>> | 80% | 42,032 psi | 65% | 2690 fps | 99% |
| Norma URP | <<locked>> | 80% | 51,198 psi | 79% | 2772 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 37,666 psi | 58% | 2595 fps | 95.8% |
| Ramshot Hunter | <<locked>> | 80% | 50,125 psi | 77% | 2776 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 33,765 psi | 52% | 2477 fps | 96.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,703 psi | 44% | 1699 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 52,982 psi | 82% | 2812 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 51,169 psi | 79% | 2831 fps | 100% |
| ReloadSwiss RS 76 | 80.3 gr | 80% | 31,676 psi | 49% | 2493 fps | 96.3% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 41,901 psi | 64% | 2707 fps | 95.9% |
| Rottweil R 904 | <<locked>> | 80% | 44,759 psi | 69% | 2654 fps | 97.6% |
| Rottweil R 905 | <<locked>> | 80% | 43,236 psi | 67% | 2661 fps | 98.3% |
| Rottweil R 907 | <<locked>> | 80% | 54,128 psi | 83% | 2789 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 80% | 53,113 psi | 82% | 2762 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 51,561 psi | 79% | 2759 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 51,909 psi | 80% | 2710 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 42,902 psi | 66% | 2654 fps | 98.2% |
| Somchem S361 | <<locked>> | 80% | 45,716 psi | 70% | 2638 fps | 97.2% |
| Somchem S365 | <<locked>> | 80% | 48,747 psi | 75% | 2730 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 43,787 psi | 67% | 2641 fps | 99% |
| Vihtavuori N160 | <<locked>> | 80% | 52,634 psi | 81% | 2766 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 38,101 psi | 59% | 2516 fps | 97.5% |
| Vihtavuori N550 | <<locked>> | 80% | 51,982 psi | 80% | 2769 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 42,815 psi | 66% | 2651 fps | 100% |
| Vihtavuori N560 | 77.8 gr | 80% | 41,887 psi | 64% | 2680 fps | 96.3% |
| Vihtavuori N565 | <<locked>> | 84% | 39,784 psi | 61% | 2618 fps | 95.9% |
| Vihtavuori N568 | <<locked>> | 90% | 43,120 psi | 66% | 2723 fps | 95.6% |
| Vihtavuori N570 | <<locked>> | 96% | 50,821 psi | 78% | 2897 fps | 95.9% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 52,141 psi | 80% | 2717 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 54,244 psi | 83% | 2844 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 35,708 psi | 55% | 2615 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 40,248 psi | 62% | 2569 fps | 97.5% |
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 71 powders for .300 Rem. Ultra Mag. loaded with the .308 | 180gr | Hornady SST InterLock. Hodgdon Retumbo delivers the highest muzzle velocity at 3,018 fps; across all powders the maximum-charge window runs from 1,850 fps to 3,018 fps. ADI AR 2217 gives the best case fill at 100 %, and 71 of the 71 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 58–90 %, leaving at least 10 % headroom. The 180.0 gr projectile in 0.308" calls for a 1:12.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Alliant Reloder-33 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. Hodgdon Retumbo, ReloadSwiss RS 76, Vihtavuori N560 rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 180gr | Hornady SST InterLock 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.