Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 180gr | Barnes X BT bullet and 62 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 80 and Vihtavuori N570.
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% | 55,869 psi | 86% | 2799 fps | 100% |
| Accurate MAGPRO | <<locked>> | 88% | 57,769 psi | 89% | 2943 fps | 99% |
| ADI AR 2209 | <<locked>> | 86% | 55,970 psi | 86% | 2871 fps | 99.8% |
| ADI AR 2213 | <<locked>> | 90% | 57,943 psi | 89% | 2936 fps | 99.6% |
| ADI AR 2217 | <<locked>> | 98% | 56,579 psi | 87% | 2904 fps | 99.7% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 53,272 psi | 82% | 2936 fps | 96.8% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 55,187 psi | 85% | 2930 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 86% | 56,217 psi | 87% | 2867 fps | 99.8% |
| Alliant Reloder-16 | <<locked>> | 82% | 56,086 psi | 86% | 2867 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 55,622 psi | 86% | 2861 fps | 99.8% |
| Alliant Reloder-22 | <<locked>> | 90% | 58,653 psi | 90% | 2933 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 90% | 56,695 psi | 87% | 2851 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 94% | 56,521 psi | 87% | 2913 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 86% | 57,435 psi | 88% | 2936 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 54,723 psi | 84% | 2933 fps | 97.2% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 58,349 psi | 90% | 2884 fps | 97.9% |
| Bofors RP15 | <<locked>> | 92% | 57,856 psi | 89% | 2923 fps | 99.9% |
| Bofors RP30 | <<locked>> | 96% | 56,652 psi | 87% | 2923 fps | 99.7% |
| Bofors RP5 | <<locked>> | 90% | 58,653 psi | 90% | 2933 fps | 100% |
| Hodgdon H1000 | <<locked>> | 96% | 58,102 psi | 89% | 2927 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 88% | 57,421 psi | 88% | 2871 fps | 99.2% |
| Hodgdon H4831 SC | <<locked>> | 88% | 56,188 psi | 86% | 2854 fps | 99% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 56,637 psi | 87% | 2792 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 94% | 55,288 psi | 85% | 2989 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,811 psi | 58% | 1847 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 58,407 psi | 90% | 2844 fps | 100% |
| IMR 4831 | <<locked>> | 82% | 55,985 psi | 86% | 2808 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 57,711 psi | 89% | 2848 fps | 99.3% |
| IMR 7828 SSC | <<locked>> | 90% | 56,362 psi | 87% | 2917 fps | 99.5% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 51,024 psi | 79% | 2854 fps | 99.2% |
| Lovex S070 | <<locked>> | 82% | 57,450 psi | 88% | 2828 fps | 100% |
| Lovex S071 | <<locked>> | 94% | 57,450 psi | 88% | 2822 fps | 100% |
| Norma 204 | <<locked>> | 82% | 56,028 psi | 86% | 2851 fps | 99.8% |
| Norma 217ᴾ | <<locked>> | 100% | 51,880 psi | 80% | 2881 fps | 100% |
| Norma MRP | <<locked>> | 86% | 55,129 psi | 85% | 2900 fps | 100% |
| Norma URP | <<locked>> | 82% | 57,145 psi | 88% | 2844 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 57,464 psi | 88% | 2936 fps | 99.8% |
| Ramshot Hunter | <<locked>> | 82% | 56,086 psi | 86% | 2851 fps | 100% |
| Ramshot Magnum | <<locked>> | 92% | 56,231 psi | 87% | 2871 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,798 psi | 60% | 1893 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 57,696 psi | 89% | 2913 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 94% | 56,304 psi | 87% | 2982 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 96% | 56,217 psi | 87% | 2946 fps | 99.1% |
| Rottweil R 904 | <<locked>> | 86% | 56,695 psi | 87% | 2838 fps | 99.4% |
| Rottweil R 905 | <<locked>> | 86% | 55,521 psi | 85% | 2854 fps | 99.8% |
| Shooters World SW4350 | <<locked>> | 82% | 57,450 psi | 88% | 2828 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 57,957 psi | 89% | 2782 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 58,697 psi | 90% | 2904 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 58,436 psi | 90% | 2828 fps | 99.2% |
| Somchem S365 | <<locked>> | 84% | 58,769 psi | 90% | 2851 fps | 100% |
| Somchem S385 | <<locked>> | 86% | 56,318 psi | 87% | 2828 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 58,552 psi | 90% | 2831 fps | 100% |
| Vihtavuori N165 | <<locked>> | 90% | 55,854 psi | 86% | 2808 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 58,131 psi | 89% | 2841 fps | 100% |
| Vihtavuori N555 | <<locked>> | 86% | 55,622 psi | 86% | 2835 fps | 100% |
| Vihtavuori N560 | <<locked>> | 88% | 58,189 psi | 90% | 2953 fps | 99.4% |
| Vihtavuori N565 | <<locked>> | 92% | 55,666 psi | 86% | 2887 fps | 99.3% |
| Vihtavuori N568 | <<locked>> | 96% | 56,536 psi | 87% | 2943 fps | 98.7% |
| Vihtavuori N570 | <<locked>> | 98% | 57,696 psi | 89% | 3002 fps | 97.4% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 58,073 psi | 89% | 2782 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 90% | 56,260 psi | 87% | 2936 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 88% | 55,753 psi | 86% | 2818 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% | 43,279 psi | 67% | 2602 fps | 99.7% |
| Accurate MAGPRO | <<locked>> | 80% | 43,932 psi | 68% | 2707 fps | 96.2% |
| ADI AR 2209 | <<locked>> | 80% | 46,093 psi | 71% | 2707 fps | 98.7% |
| ADI AR 2213 | <<locked>> | 80% | 41,568 psi | 64% | 2648 fps | 96.6% |
| ADI AR 2217 | <<locked>> | 86% | 38,348 psi | 59% | 2572 fps | 95.9% |
| ADI AR 2218 | <<locked>> | 98% | 49,632 psi | 76% | 2867 fps | 95.6% |
| ADI AR 2225 | <<locked>> | 80% | 29,370 psi | 45% | 2382 fps | 95% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 46,557 psi | 72% | 2707 fps | 98.8% |
| Alliant Reloder-16 | <<locked>> | 80% | 52,634 psi | 81% | 2815 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 46,166 psi | 71% | 2703 fps | 98.7% |
| Alliant Reloder-22 | <<locked>> | 80% | 42,467 psi | 65% | 2661 fps | 98.1% |
| Alliant Reloder-23 | <<locked>> | 80% | 41,263 psi | 64% | 2615 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 35,926 psi | 55% | 2552 fps | 99.2% |
| Alliant Reloder-26 | <<locked>> | 80% | 46,369 psi | 71% | 2769 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 47,355 psi | 73% | 2805 fps | 95.3% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 48,660 psi | 75% | 2720 fps | 95.7% |
| Bofors RP15 | <<locked>> | 80% | 39,697 psi | 61% | 2605 fps | 97.2% |
| Bofors RP30 | <<locked>> | 82% | 35,911 psi | 55% | 2543 fps | 95.3% |
| Bofors RP5 | <<locked>> | 80% | 42,467 psi | 65% | 2661 fps | 98.1% |
| Hodgdon H1000 | <<locked>> | 82% | 36,550 psi | 56% | 2533 fps | 95.9% |
| Hodgdon H4831 | <<locked>> | 80% | 44,179 psi | 68% | 2648 fps | 96.7% |
| Hodgdon H4831 SC | <<locked>> | 80% | 43,424 psi | 67% | 2635 fps | 96.5% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 49,908 psi | 77% | 2700 fps | 100% |
| Hodgdon Retumbo | 73.9 gr | 80% | 35,128 psi | 54% | 2582 fps | 96.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,456 psi | 44% | 1660 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 51,663 psi | 80% | 2746 fps | 99.8% |
| IMR 4831 | <<locked>> | 80% | 52,504 psi | 81% | 2759 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 45,223 psi | 70% | 2641 fps | 97.1% |
| IMR 7828 SSC | <<locked>> | 80% | 40,321 psi | 62% | 2631 fps | 96.3% |
| IMR 8133 Enduron | <<locked>> | 90% | 36,941 psi | 57% | 2582 fps | 95.6% |
| Lovex S070 | <<locked>> | 80% | 54,128 psi | 83% | 2782 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 37,652 psi | 58% | 2490 fps | 98.8% |
| Norma 204 | <<locked>> | 80% | 52,460 psi | 81% | 2795 fps | 99.5% |
| Norma 217 | <<locked>> | 84% | 30,850 psi | 47% | 2448 fps | 95.2% |
| Norma MRP | <<locked>> | 80% | 44,918 psi | 69% | 2733 fps | 99.5% |
| Norma URP | <<locked>> | 80% | 53,737 psi | 83% | 2799 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 40,422 psi | 62% | 2644 fps | 96.8% |
| Ramshot Hunter | <<locked>> | 80% | 52,620 psi | 81% | 2799 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 36,724 psi | 57% | 2533 fps | 97.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,109 psi | 45% | 1696 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 53,708 psi | 83% | 2854 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 34,548 psi | 53% | 2559 fps | 97.6% |
| ReloadSwiss RS 80 | 87.7 gr | 88% | 42,003 psi | 65% | 2697 fps | 95.9% |
| Rottweil R 904 | <<locked>> | 80% | 47,137 psi | 73% | 2684 fps | 98% |
| Rottweil R 905 | <<locked>> | 80% | 45,803 psi | 70% | 2694 fps | 98.8% |
| Shooters World SW4350 | <<locked>> | 80% | 54,128 psi | 83% | 2782 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 54,549 psi | 84% | 2736 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 45,455 psi | 70% | 2690 fps | 98.7% |
| Somchem S361 | <<locked>> | 80% | 48,196 psi | 74% | 2667 fps | 97.7% |
| Somchem S365 | <<locked>> | 80% | 51,561 psi | 79% | 2756 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 46,630 psi | 72% | 2677 fps | 99.4% |
| Vihtavuori N160 | <<locked>> | 80% | 55,085 psi | 85% | 2785 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 40,727 psi | 63% | 2556 fps | 98.1% |
| Vihtavuori N550 | <<locked>> | 80% | 54,578 psi | 84% | 2792 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 46,209 psi | 71% | 2694 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 44,541 psi | 69% | 2720 fps | 97% |
| Vihtavuori N565 | <<locked>> | 80% | 37,782 psi | 58% | 2559 fps | 95.1% |
| Vihtavuori N568 | <<locked>> | 88% | 43,033 psi | 66% | 2710 fps | 95.6% |
| Vihtavuori N570 | 90.1 gr | 94% | 50,096 psi | 77% | 2877 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 54,317 psi | 84% | 2733 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 38,957 psi | 60% | 2671 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 42,844 psi | 66% | 2605 fps | 98.1% |
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 62 powders for .300 Rem. Ultra Mag. loaded with the .308 | 180gr | Barnes X BT. Vihtavuori N570 delivers the highest muzzle velocity at 3,002 fps; across all powders the maximum-charge window runs from 1,847 fps to 3,002 fps. ADI AR 2218 gives the best case fill at 100 %, and 62 of the 62 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 1:11.5 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, ReloadSwiss RS 80, Vihtavuori N570 rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 180gr | Barnes X BT 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.