Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 180gr | Barnes X S bullet and 61 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon Retumbo, Vihtavuori N570 and ReloadSwiss RS 76.
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>> | 88% | 56,173 psi | 86% | 2805 fps | 100% |
| Accurate MAGPRO | <<locked>> | 88% | 58,030 psi | 89% | 2946 fps | 99.1% |
| ADI AR 2209 | <<locked>> | 86% | 56,217 psi | 87% | 2874 fps | 99.8% |
| ADI AR 2213 | <<locked>> | 90% | 58,233 psi | 90% | 2940 fps | 99.6% |
| ADI AR 2217 | <<locked>> | 98% | 56,782 psi | 87% | 2907 fps | 99.7% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 53,679 psi | 83% | 2943 fps | 96.9% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 55,405 psi | 85% | 2930 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 86% | 56,521 psi | 87% | 2874 fps | 99.8% |
| Alliant Reloder-16 | <<locked>> | 82% | 56,231 psi | 87% | 2867 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 55,927 psi | 86% | 2864 fps | 99.8% |
| Alliant Reloder-22 | <<locked>> | 88% | 55,245 psi | 85% | 2884 fps | 99.8% |
| Alliant Reloder-23 | <<locked>> | 90% | 57,014 psi | 88% | 2854 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 94% | 56,797 psi | 87% | 2917 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 86% | 57,986 psi | 89% | 2943 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 55,100 psi | 85% | 2940 fps | 97.3% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 58,726 psi | 90% | 2890 fps | 98% |
| Bofors RP15 | <<locked>> | 92% | 58,131 psi | 89% | 2927 fps | 99.9% |
| Bofors RP30 | <<locked>> | 96% | 56,971 psi | 88% | 2927 fps | 99.8% |
| Bofors RP5 | <<locked>> | 88% | 55,245 psi | 85% | 2884 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 96% | 58,392 psi | 90% | 2930 fps | 100% |
| Hodgdon H4831 | <<locked>> | 88% | 57,696 psi | 89% | 2874 fps | 99.2% |
| Hodgdon H4831 SC | <<locked>> | 88% | 56,492 psi | 87% | 2858 fps | 99.1% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 56,753 psi | 87% | 2792 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 94% | 55,767 psi | 86% | 2995 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,739 psi | 58% | 1847 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 58,523 psi | 90% | 2848 fps | 100% |
| IMR 4831 | <<locked>> | 82% | 56,130 psi | 86% | 2812 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 57,972 psi | 89% | 2851 fps | 99.3% |
| IMR 7828 SSC | <<locked>> | 90% | 56,666 psi | 87% | 2923 fps | 99.5% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 51,271 psi | 79% | 2858 fps | 99.2% |
| Lovex S070 | <<locked>> | 82% | 57,754 psi | 89% | 2835 fps | 100% |
| Lovex S071 | <<locked>> | 94% | 57,740 psi | 89% | 2825 fps | 100% |
| Norma 204 | <<locked>> | 82% | 56,347 psi | 87% | 2854 fps | 99.8% |
| Norma 217ᴾ | <<locked>> | 100% | 52,185 psi | 80% | 2884 fps | 100% |
| Norma MRP | <<locked>> | 86% | 55,419 psi | 85% | 2904 fps | 100% |
| Norma URP | <<locked>> | 82% | 57,508 psi | 89% | 2851 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 57,856 psi | 89% | 2943 fps | 99.8% |
| Ramshot Hunter | <<locked>> | 82% | 56,405 psi | 87% | 2854 fps | 100% |
| Ramshot Magnum | <<locked>> | 92% | 56,739 psi | 87% | 2877 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,725 psi | 60% | 1893 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 58,030 psi | 89% | 2913 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 94% | 56,768 psi | 87% | 2986 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 96% | 56,681 psi | 87% | 2953 fps | 99.1% |
| Rottweil R 904 | <<locked>> | 86% | 56,956 psi | 88% | 2841 fps | 99.5% |
| Rottweil R 905 | <<locked>> | 86% | 55,840 psi | 86% | 2858 fps | 99.9% |
| Shooters World SW4350 | <<locked>> | 82% | 57,754 psi | 89% | 2835 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 58,276 psi | 90% | 2789 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 55,434 psi | 85% | 2854 fps | 99.8% |
| Somchem S361 | <<locked>> | 86% | 58,668 psi | 90% | 2831 fps | 99.3% |
| Somchem S365 | <<locked>> | 82% | 55,317 psi | 85% | 2808 fps | 100% |
| Somchem S385 | <<locked>> | 86% | 56,536 psi | 87% | 2831 fps | 100% |
| Vihtavuori N165 | <<locked>> | 90% | 56,144 psi | 86% | 2812 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 58,465 psi | 90% | 2844 fps | 100% |
| Vihtavuori N555 | <<locked>> | 86% | 55,941 psi | 86% | 2838 fps | 100% |
| Vihtavuori N560 | <<locked>> | 88% | 58,537 psi | 90% | 2956 fps | 99.4% |
| Vihtavuori N565 | <<locked>> | 92% | 56,130 psi | 86% | 2894 fps | 99.3% |
| Vihtavuori N568 | <<locked>> | 96% | 57,029 psi | 88% | 2953 fps | 98.8% |
| Vihtavuori N570 | <<locked>> | 98% | 57,914 psi | 89% | 3005 fps | 97.5% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 58,349 psi | 90% | 2785 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 90% | 56,608 psi | 87% | 2940 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 56,014 psi | 86% | 2822 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 3100 | <<locked>> | 80% | 43,555 psi | 67% | 2605 fps | 99.7% |
| Accurate MAGPRO | <<locked>> | 80% | 44,193 psi | 68% | 2710 fps | 96.3% |
| ADI AR 2209 | <<locked>> | 80% | 46,369 psi | 71% | 2713 fps | 98.8% |
| ADI AR 2213 | <<locked>> | 80% | 41,843 psi | 64% | 2654 fps | 96.7% |
| ADI AR 2217 | <<locked>> | 84% | 36,143 psi | 56% | 2520 fps | 95% |
| ADI AR 2218 | <<locked>> | 98% | 50,038 psi | 77% | 2877 fps | 95.8% |
| ADI AR 2225 | <<locked>> | 80% | 29,559 psi | 45% | 2388 fps | 95.1% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 46,847 psi | 72% | 2713 fps | 98.8% |
| Alliant Reloder-16 | <<locked>> | 80% | 52,765 psi | 81% | 2818 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 46,427 psi | 71% | 2707 fps | 98.8% |
| Alliant Reloder-22 | <<locked>> | 80% | 42,728 psi | 66% | 2667 fps | 98.2% |
| Alliant Reloder-23 | <<locked>> | 80% | 41,568 psi | 64% | 2621 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 36,187 psi | 56% | 2559 fps | 99.3% |
| Alliant Reloder-26 | <<locked>> | 80% | 46,702 psi | 72% | 2776 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 47,776 psi | 74% | 2815 fps | 95.4% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 48,863 psi | 75% | 2726 fps | 95.8% |
| Bofors RP15 | <<locked>> | 80% | 39,943 psi | 61% | 2608 fps | 97.3% |
| Bofors RP30 | <<locked>> | 82% | 36,187 psi | 56% | 2546 fps | 95.4% |
| Bofors RP5 | <<locked>> | 80% | 42,728 psi | 66% | 2667 fps | 98.2% |
| Hodgdon H1000 | <<locked>> | 82% | 36,753 psi | 57% | 2536 fps | 96% |
| Hodgdon H4831 | <<locked>> | 80% | 44,454 psi | 68% | 2654 fps | 96.8% |
| Hodgdon H4831 SC | <<locked>> | 80% | 43,700 psi | 67% | 2641 fps | 96.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 50,241 psi | 77% | 2703 fps | 100% |
| Hodgdon Retumbo | 74.3 gr | 80% | 35,360 psi | 54% | 2585 fps | 96.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,442 psi | 44% | 1660 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 51,967 psi | 80% | 2753 fps | 99.9% |
| IMR 4831 | <<locked>> | 80% | 52,852 psi | 81% | 2766 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 45,469 psi | 70% | 2648 fps | 97.2% |
| IMR 7828 SSC | <<locked>> | 80% | 40,611 psi | 63% | 2638 fps | 96.4% |
| IMR 8133 Enduron | <<locked>> | 90% | 37,188 psi | 57% | 2585 fps | 95.7% |
| Lovex S070 | <<locked>> | 80% | 54,418 psi | 84% | 2785 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 37,942 psi | 58% | 2497 fps | 98.9% |
| Norma 204 | <<locked>> | 80% | 52,765 psi | 81% | 2799 fps | 99.5% |
| Norma 217 | <<locked>> | 84% | 31,082 psi | 48% | 2454 fps | 95.4% |
| Norma MRP | <<locked>> | 80% | 45,179 psi | 70% | 2736 fps | 99.5% |
| Norma URP | <<locked>> | 80% | 54,056 psi | 83% | 2802 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 40,538 psi | 62% | 2644 fps | 96.8% |
| Ramshot Hunter | <<locked>> | 80% | 52,924 psi | 81% | 2805 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 36,970 psi | 57% | 2539 fps | 97.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,240 psi | 45% | 1699 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 54,056 psi | 83% | 2861 fps | 100% |
| ReloadSwiss RS 76 | 79.5 gr | 80% | 34,751 psi | 53% | 2566 fps | 97.8% |
| ReloadSwiss RS 80 | <<locked>> | 88% | 42,279 psi | 65% | 2703 fps | 96% |
| Rottweil R 904 | <<locked>> | 80% | 47,224 psi | 73% | 2684 fps | 98.1% |
| Rottweil R 905 | <<locked>> | 80% | 46,122 psi | 71% | 2700 fps | 98.8% |
| Shooters World SW4350 | <<locked>> | 80% | 54,418 psi | 84% | 2785 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 54,636 psi | 84% | 2736 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 45,774 psi | 70% | 2694 fps | 98.8% |
| Somchem S361 | <<locked>> | 80% | 48,457 psi | 75% | 2674 fps | 97.7% |
| Somchem S365 | <<locked>> | 80% | 51,924 psi | 80% | 2759 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 46,891 psi | 72% | 2680 fps | 99.4% |
| Vihtavuori N165 | <<locked>> | 80% | 40,988 psi | 63% | 2559 fps | 98.2% |
| Vihtavuori N550 | <<locked>> | 80% | 54,911 psi | 85% | 2795 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 46,369 psi | 71% | 2697 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 44,860 psi | 69% | 2726 fps | 97.1% |
| Vihtavuori N565 | <<locked>> | 80% | 38,029 psi | 59% | 2562 fps | 95.2% |
| Vihtavuori N568 | <<locked>> | 88% | 43,308 psi | 67% | 2713 fps | 95.7% |
| Vihtavuori N570 | 90.6 gr | 94% | 50,560 psi | 78% | 2884 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 54,592 psi | 84% | 2736 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 39,247 psi | 60% | 2677 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 43,120 psi | 66% | 2612 fps | 98.2% |
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 61 powders for .300 Rem. Ultra Mag. loaded with the .308 | 180gr | Barnes X S. Vihtavuori N570 delivers the highest muzzle velocity at 3,005 fps; across all powders the maximum-charge window runs from 1,847 fps to 3,005 fps. ADI AR 2218 gives the best case fill at 100 %, and 61 of the 61 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 2218, ADI AR 2225, Hodgdon TrailBoss 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, Vihtavuori N570, ReloadSwiss RS 76 rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 180gr | Barnes X S 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.