Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 165gr | Barnes X BT bullet and 68 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% | 56,971 psi | 88% | 2917 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 57,232 psi | 88% | 2943 fps | 100% |
| Accurate MAGPRO | <<locked>> | 88% | 55,042 psi | 85% | 2999 fps | 98% |
| ADI AR 2209 | <<locked>> | 88% | 57,290 psi | 88% | 2989 fps | 99.6% |
| ADI AR 2213 | <<locked>> | 90% | 55,390 psi | 85% | 2995 fps | 98.9% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 57,667 psi | 89% | 3015 fps | 99.5% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 52,591 psi | 81% | 2986 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 57,188 psi | 88% | 2989 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 56,927 psi | 88% | 2979 fps | 99.6% |
| Alliant Reloder-22 | <<locked>> | 90% | 56,144 psi | 86% | 2995 fps | 99.6% |
| Alliant Reloder-23 | <<locked>> | 92% | 57,740 psi | 89% | 2969 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 57,435 psi | 88% | 3031 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 58,726 psi | 90% | 3058 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 55,811 psi | 86% | 3041 fps | 96.7% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 56,376 psi | 87% | 2943 fps | 96.8% |
| Bofors RP15 | <<locked>> | 92% | 55,332 psi | 85% | 2982 fps | 99.5% |
| Bofors RP30 | <<locked>> | 98% | 57,711 psi | 89% | 3038 fps | 99.5% |
| Bofors RP5 | <<locked>> | 90% | 56,144 psi | 86% | 2995 fps | 99.6% |
| Bofors RP7 | <<locked>> | 82% | 58,073 psi | 89% | 2936 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 96% | 55,463 psi | 85% | 2986 fps | 99.5% |
| Hodgdon H414 | <<locked>> | 82% | 57,957 psi | 89% | 2989 fps | 100% |
| Hodgdon H4831 | <<locked>> | 88% | 55,172 psi | 85% | 2933 fps | 98.3% |
| Hodgdon H4831 SC | <<locked>> | 90% | 57,725 psi | 89% | 2972 fps | 98.7% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 57,711 psi | 89% | 2910 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 56,289 psi | 87% | 3107 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,623 psi | 58% | 1926 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 56,391 psi | 87% | 2920 fps | 99.9% |
| IMR 4831 | <<locked>> | 84% | 57,261 psi | 88% | 2933 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 55,724 psi | 86% | 2917 fps | 98.5% |
| IMR 7828 SSC | <<locked>> | 92% | 57,363 psi | 88% | 3031 fps | 99.2% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 48,312 psi | 74% | 2900 fps | 98.2% |
| Lovex S065 | <<locked>> | 82% | 57,072 psi | 88% | 2907 fps | 100% |
| Lovex S070 | <<locked>> | 82% | 55,521 psi | 85% | 2904 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 58,436 psi | 90% | 2936 fps | 100% |
| Norma 204 | <<locked>> | 84% | 57,638 psi | 89% | 2976 fps | 99.6% |
| Norma 217ᴾ | <<locked>> | 100% | 48,950 psi | 75% | 2930 fps | 99.7% |
| Norma MRP | <<locked>> | 88% | 56,217 psi | 87% | 3018 fps | 100% |
| Norma URP | <<locked>> | 84% | 58,494 psi | 90% | 2969 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 58,755 psi | 90% | 3058 fps | 99.6% |
| Ramshot Hunter | <<locked>> | 84% | 57,609 psi | 89% | 2976 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 57,522 psi | 89% | 2989 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,551 psi | 59% | 1969 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 57,101 psi | 88% | 2959 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 55,056 psi | 85% | 2982 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 57,479 psi | 88% | 3097 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 57,217 psi | 88% | 3054 fps | 98.7% |
| Rottweil R 904 | <<locked>> | 88% | 58,160 psi | 90% | 2959 fps | 99.2% |
| Rottweil R 905 | <<locked>> | 88% | 56,826 psi | 87% | 2972 fps | 99.7% |
| Rottweil R 907 | <<locked>> | 82% | 58,073 psi | 89% | 2936 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 82% | 57,072 psi | 88% | 2907 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 55,521 psi | 85% | 2904 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 56,043 psi | 86% | 2854 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 56,405 psi | 87% | 2969 fps | 99.6% |
| Somchem S361 | <<locked>> | 86% | 56,304 psi | 87% | 2890 fps | 98.5% |
| Somchem S365 | <<locked>> | 84% | 56,260 psi | 87% | 2927 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 57,508 psi | 89% | 2946 fps | 99.9% |
| Vihtavuori N160 | <<locked>> | 82% | 56,449 psi | 87% | 2910 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 57,188 psi | 88% | 2923 fps | 99.8% |
| Vihtavuori N550 | <<locked>> | 82% | 55,985 psi | 86% | 2917 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 56,565 psi | 87% | 2953 fps | 100% |
| Vihtavuori N560 | <<locked>> | 88% | 55,637 psi | 86% | 3009 fps | 98.6% |
| Vihtavuori N565 | <<locked>> | 94% | 56,753 psi | 87% | 3002 fps | 99% |
| Vihtavuori N568 | <<locked>> | 98% | 57,754 psi | 89% | 3058 fps | 98.3% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 58,537 psi | 90% | 3110 fps | 96.8% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 55,956 psi | 86% | 2858 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 58,131 psi | 89% | 2989 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 57,014 psi | 88% | 3058 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 57,174 psi | 88% | 2936 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 3100 | <<locked>> | 80% | 41,452 psi | 64% | 2657 fps | 99.1% |
| Accurate 4350 | <<locked>> | 80% | 53,780 psi | 83% | 2894 fps | 100% |
| Accurate MAGPRO | <<locked>> | 82% | 44,962 psi | 69% | 2818 fps | 95.6% |
| ADI AR 2209 | <<locked>> | 80% | 44,092 psi | 68% | 2766 fps | 97.6% |
| ADI AR 2213 | <<locked>> | 80% | 39,885 psi | 61% | 2700 fps | 95% |
| ADI AR 2217 | <<locked>> | 88% | 38,986 psi | 60% | 2667 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 84% | 31,705 psi | 49% | 2530 fps | 95.2% |
| Alliant Reloder-16 | <<locked>> | 80% | 50,386 psi | 78% | 2890 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 44,353 psi | 68% | 2762 fps | 97.7% |
| Alliant Reloder-22 | <<locked>> | 80% | 40,582 psi | 62% | 2717 fps | 96.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 39,262 psi | 60% | 2677 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 34,214 psi | 53% | 2598 fps | 98.1% |
| Alliant Reloder-26 | <<locked>> | 80% | 44,063 psi | 68% | 2831 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 51,735 psi | 80% | 2976 fps | 95.6% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 50,009 psi | 77% | 2831 fps | 95.1% |
| Bofors RP15 | <<locked>> | 80% | 37,855 psi | 58% | 2651 fps | 95.7% |
| Bofors RP30 | <<locked>> | 86% | 38,943 psi | 60% | 2700 fps | 95.5% |
| Bofors RP5 | <<locked>> | 80% | 40,582 psi | 62% | 2717 fps | 96.8% |
| Bofors RP7 | <<locked>> | 80% | 54,679 psi | 84% | 2884 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 84% | 37,333 psi | 57% | 2631 fps | 95.1% |
| Hodgdon H414 | <<locked>> | 80% | 54,360 psi | 84% | 2933 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 80% | 42,409 psi | 65% | 2703 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 80% | 41,698 psi | 64% | 2687 fps | 95% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 47,863 psi | 74% | 2769 fps | 100% |
| Hodgdon Retumbo | 77 gr | 82% | 35,665 psi | 55% | 2677 fps | 95.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,297 psi | 44% | 1729 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 49,763 psi | 77% | 2812 fps | 99.4% |
| IMR 4831 | <<locked>> | 80% | 50,546 psi | 78% | 2831 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 43,511 psi | 67% | 2697 fps | 95.8% |
| IMR 7828 SSC | <<locked>> | 82% | 41,263 psi | 64% | 2743 fps | 95.7% |
| IMR 8133 Enduron | <<locked>> | 94% | 39,755 psi | 61% | 2733 fps | 95.7% |
| Lovex S065 | <<locked>> | 80% | 53,606 psi | 83% | 2854 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 52,141 psi | 80% | 2851 fps | 99.8% |
| Lovex S071 | <<locked>> | 80% | 36,042 psi | 55% | 2546 fps | 97.8% |
| Norma 204 | <<locked>> | 80% | 50,473 psi | 78% | 2861 fps | 98.8% |
| Norma 217 | <<locked>> | 88% | 33,185 psi | 51% | 2592 fps | 95.4% |
| Norma MRP | <<locked>> | 80% | 42,772 psi | 66% | 2785 fps | 98.6% |
| Norma URP | <<locked>> | 80% | 51,590 psi | 79% | 2871 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 38,522 psi | 59% | 2687 fps | 95% |
| Ramshot Hunter | <<locked>> | 80% | 50,575 psi | 78% | 2867 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 80% | 34,940 psi | 54% | 2575 fps | 95.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,037 psi | 45% | 1772 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 53,403 psi | 82% | 2907 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 51,271 psi | 79% | 2923 fps | 100% |
| ReloadSwiss RS 76 | 80.4 gr | 80% | 32,866 psi | 51% | 2592 fps | 95.7% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 42,685 psi | 66% | 2802 fps | 95.2% |
| Rottweil R 904 | <<locked>> | 80% | 45,324 psi | 70% | 2743 fps | 96.9% |
| Rottweil R 905 | <<locked>> | 80% | 43,961 psi | 68% | 2753 fps | 97.8% |
| Rottweil R 907 | <<locked>> | 80% | 54,679 psi | 84% | 2884 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 53,606 psi | 83% | 2854 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 52,141 psi | 80% | 2851 fps | 99.8% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 52,663 psi | 81% | 2802 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 43,671 psi | 67% | 2749 fps | 97.7% |
| Somchem S361 | <<locked>> | 80% | 46,412 psi | 71% | 2726 fps | 96.5% |
| Somchem S365 | <<locked>> | 80% | 49,226 psi | 76% | 2828 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 44,802 psi | 69% | 2736 fps | 98.6% |
| Vihtavuori N160 | <<locked>> | 80% | 53,098 psi | 82% | 2861 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 39,088 psi | 60% | 2612 fps | 96.9% |
| Vihtavuori N550 | <<locked>> | 80% | 52,634 psi | 81% | 2864 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 44,092 psi | 68% | 2756 fps | 100% |
| Vihtavuori N560 | 78 gr | 80% | 42,511 psi | 65% | 2769 fps | 95.5% |
| Vihtavuori N565 | <<locked>> | 84% | 40,944 psi | 63% | 2713 fps | 95.3% |
| Vihtavuori N568 | <<locked>> | 92% | 46,891 psi | 72% | 2874 fps | 95.9% |
| Vihtavuori N570 | <<locked>> | 98% | 54,737 psi | 84% | 3051 fps | 96% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 52,185 psi | 80% | 2805 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 54,563 psi | 84% | 2936 fps | 99.9% |
| Winchester StaBALL HD | <<locked>> | 80% | 36,448 psi | 56% | 2723 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 41,075 psi | 63% | 2661 fps | 96.9% |
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 68 powders for .300 Rem. Ultra Mag. loaded with the .308 | 165gr | Barnes X BT. Vihtavuori N570 delivers the highest muzzle velocity at 3,110 fps; across all powders the maximum-charge window runs from 1,926 fps to 3,110 fps. ADI AR 2217 gives the best case fill at 100 %, and 68 of the 68 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 165.0 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 | 165gr | 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.