Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 170gr | Swift A-Frame 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% | 57,072 psi | 88% | 2894 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 57,232 psi | 88% | 2923 fps | 100% |
| Accurate MAGPRO | <<locked>> | 88% | 55,840 psi | 86% | 2986 fps | 98.6% |
| ADI AR 2209 | <<locked>> | 88% | 58,276 psi | 90% | 2982 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 90% | 56,579 psi | 87% | 2992 fps | 99.4% |
| ADI AR 2217 | <<locked>> | 98% | 55,245 psi | 85% | 2959 fps | 99.5% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 53,708 psi | 83% | 2976 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 58,508 psi | 90% | 2979 fps | 99.9% |
| Alliant Reloder-16 | <<locked>> | 84% | 58,218 psi | 90% | 2976 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 57,841 psi | 89% | 2972 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 90% | 56,985 psi | 88% | 2986 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 92% | 58,740 psi | 90% | 2953 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 94% | 55,027 psi | 85% | 2966 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 86% | 55,608 psi | 86% | 2982 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 57,435 psi | 88% | 3038 fps | 97.6% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 57,522 psi | 89% | 2946 fps | 97.6% |
| Bofors RP15 | <<locked>> | 92% | 56,159 psi | 86% | 2972 fps | 99.8% |
| Bofors RP30 | <<locked>> | 98% | 58,784 psi | 90% | 3028 fps | 99.8% |
| Bofors RP5 | <<locked>> | 90% | 56,985 psi | 88% | 2986 fps | 99.9% |
| Bofors RP7 | <<locked>> | 82% | 58,320 psi | 90% | 2920 fps | 100% |
| Hodgdon H1000 | <<locked>> | 96% | 56,855 psi | 88% | 2982 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 82% | 58,653 psi | 90% | 2972 fps | 100% |
| Hodgdon H4831 | <<locked>> | 88% | 55,941 psi | 86% | 2927 fps | 98.9% |
| Hodgdon H4831 SC | <<locked>> | 90% | 58,711 psi | 90% | 2966 fps | 99.2% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 58,523 psi | 90% | 2897 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 57,711 psi | 89% | 3097 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,362 psi | 57% | 1916 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 56,913 psi | 88% | 2907 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 57,464 psi | 88% | 2910 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 56,391 psi | 87% | 2910 fps | 99% |
| IMR 7828 SSC | <<locked>> | 90% | 54,752 psi | 84% | 2969 fps | 99.2% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 49,008 psi | 75% | 2887 fps | 98.7% |
| Lovex S065 | <<locked>> | 82% | 57,188 psi | 88% | 2890 fps | 100% |
| Lovex S070 | <<locked>> | 82% | 55,506 psi | 85% | 2884 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 58,494 psi | 90% | 2913 fps | 100% |
| Norma 204 | <<locked>> | 84% | 58,465 psi | 90% | 2966 fps | 99.8% |
| Norma 217ᴾ | <<locked>> | 100% | 49,922 psi | 77% | 2913 fps | 99.9% |
| Norma MRP | <<locked>> | 88% | 57,043 psi | 88% | 3002 fps | 100% |
| Norma URP | <<locked>> | 82% | 55,332 psi | 85% | 2900 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 55,927 psi | 86% | 2992 fps | 99.6% |
| Ramshot Hunter | <<locked>> | 84% | 58,305 psi | 90% | 2959 fps | 100% |
| Ramshot Magnum | <<locked>> | 92% | 54,563 psi | 84% | 2920 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,348 psi | 59% | 1962 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 57,653 psi | 89% | 2943 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 56,202 psi | 86% | 2969 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 94% | 54,926 psi | 85% | 3028 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 58,726 psi | 90% | 3051 fps | 99.3% |
| Rottweil R 904 | <<locked>> | 86% | 55,158 psi | 85% | 2894 fps | 99.2% |
| Rottweil R 905 | <<locked>> | 88% | 57,464 psi | 88% | 2963 fps | 99.9% |
| Rottweil R 907 | <<locked>> | 82% | 58,320 psi | 90% | 2920 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 82% | 57,188 psi | 88% | 2890 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 55,506 psi | 85% | 2884 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 56,202 psi | 86% | 2841 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 57,043 psi | 88% | 2956 fps | 99.9% |
| Somchem S361 | <<locked>> | 86% | 56,840 psi | 87% | 2884 fps | 99% |
| Somchem S365 | <<locked>> | 84% | 56,652 psi | 87% | 2907 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 57,943 psi | 89% | 2930 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 56,927 psi | 88% | 2894 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 57,899 psi | 89% | 2913 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 56,376 psi | 87% | 2897 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 56,782 psi | 87% | 2933 fps | 100% |
| Vihtavuori N560 | <<locked>> | 88% | 56,521 psi | 87% | 3002 fps | 99.1% |
| Vihtavuori N565 | <<locked>> | 94% | 57,479 psi | 88% | 2989 fps | 99.4% |
| Vihtavuori N568 | <<locked>> | 96% | 54,882 psi | 84% | 2989 fps | 98.3% |
| Vihtavuori N570 | <<locked>> | 98% | 56,115 psi | 86% | 3048 fps | 96.9% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 56,608 psi | 87% | 2838 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 58,697 psi | 90% | 3038 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 58,102 psi | 89% | 2927 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% | 40,379 psi | 62% | 2621 fps | 99.2% |
| Accurate 4350 | <<locked>> | 80% | 53,345 psi | 82% | 2867 fps | 100% |
| Accurate MAGPRO | <<locked>> | 80% | 41,829 psi | 64% | 2733 fps | 95.1% |
| ADI AR 2209 | <<locked>> | 80% | 44,353 psi | 68% | 2749 fps | 98.1% |
| ADI AR 2213 | <<locked>> | 80% | 39,784 psi | 61% | 2680 fps | 95.6% |
| ADI AR 2217 | <<locked>> | 88% | 39,015 psi | 60% | 2654 fps | 95.8% |
| ADI AR 2225 | <<locked>> | 84% | 30,951 psi | 48% | 2493 fps | 95.5% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 44,715 psi | 69% | 2749 fps | 98.2% |
| Alliant Reloder-16 | <<locked>> | 80% | 50,966 psi | 78% | 2874 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 44,309 psi | 68% | 2743 fps | 98.2% |
| Alliant Reloder-22 | <<locked>> | 80% | 40,393 psi | 62% | 2690 fps | 97.3% |
| Alliant Reloder-23 | <<locked>> | 80% | 39,001 psi | 60% | 2644 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 33,721 psi | 52% | 2566 fps | 98.4% |
| Alliant Reloder-26 | <<locked>> | 80% | 44,063 psi | 68% | 2799 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 96% | 49,081 psi | 76% | 2900 fps | 95.5% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 47,456 psi | 73% | 2772 fps | 95.1% |
| Bofors RP15 | <<locked>> | 80% | 37,550 psi | 58% | 2625 fps | 96.1% |
| Bofors RP30 | <<locked>> | 86% | 38,682 psi | 60% | 2671 fps | 96% |
| Bofors RP5 | <<locked>> | 80% | 40,393 psi | 62% | 2690 fps | 97.3% |
| Bofors RP7 | <<locked>> | 80% | 54,752 psi | 84% | 2867 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 84% | 37,057 psi | 57% | 2612 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 80% | 54,839 psi | 84% | 2920 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 42,380 psi | 65% | 2687 fps | 95.9% |
| Hodgdon H4831 SC | <<locked>> | 80% | 41,611 psi | 64% | 2671 fps | 95.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 47,979 psi | 74% | 2749 fps | 100% |
| Hodgdon Retumbo | 80.8 gr | 82% | 35,259 psi | 54% | 2651 fps | 96.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,007 psi | 43% | 1719 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 50,053 psi | 77% | 2802 fps | 99.6% |
| IMR 4831 | <<locked>> | 80% | 50,372 psi | 78% | 2808 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 43,598 psi | 67% | 2684 fps | 96.4% |
| IMR 7828 SSC | <<locked>> | 80% | 38,450 psi | 59% | 2661 fps | 95.2% |
| IMR 8133 Enduron | <<locked>> | 92% | 37,144 psi | 57% | 2648 fps | 95.2% |
| Lovex S065 | <<locked>> | 80% | 53,577 psi | 82% | 2838 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 52,141 psi | 80% | 2835 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 34,780 psi | 54% | 2500 fps | 97.8% |
| Norma 204 | <<locked>> | 80% | 50,850 psi | 78% | 2844 fps | 99.2% |
| Norma 217 | <<locked>> | 88% | 32,474 psi | 50% | 2552 fps | 95.6% |
| Norma MRP | <<locked>> | 80% | 42,873 psi | 66% | 2762 fps | 99% |
| Norma URP | <<locked>> | 80% | 51,866 psi | 80% | 2851 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 38,319 psi | 59% | 2664 fps | 95.6% |
| Ramshot Hunter | <<locked>> | 80% | 50,879 psi | 78% | 2851 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 34,432 psi | 53% | 2543 fps | 96.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,674 psi | 44% | 1759 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 53,679 psi | 83% | 2887 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 52,185 psi | 80% | 2910 fps | 100% |
| ReloadSwiss RS 76 | 84.4 gr | 80% | 32,227 psi | 50% | 2556 fps | 96% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 42,989 psi | 66% | 2779 fps | 95.9% |
| Rottweil R 904 | <<locked>> | 80% | 45,310 psi | 70% | 2726 fps | 97.4% |
| Rottweil R 905 | <<locked>> | 80% | 43,961 psi | 68% | 2733 fps | 98.2% |
| Rottweil R 907 | <<locked>> | 80% | 54,752 psi | 84% | 2867 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 80% | 53,577 psi | 82% | 2838 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 52,141 psi | 80% | 2835 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 52,547 psi | 81% | 2785 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 43,613 psi | 67% | 2730 fps | 98.1% |
| Somchem S361 | <<locked>> | 80% | 46,485 psi | 72% | 2713 fps | 97.1% |
| Somchem S365 | <<locked>> | 80% | 49,400 psi | 76% | 2805 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 44,411 psi | 68% | 2710 fps | 98.9% |
| Vihtavuori N160 | <<locked>> | 80% | 53,200 psi | 82% | 2841 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 38,595 psi | 59% | 2582 fps | 97.3% |
| Vihtavuori N550 | <<locked>> | 80% | 52,765 psi | 81% | 2844 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 43,497 psi | 67% | 2723 fps | 100% |
| Vihtavuori N560 | 81.9 gr | 80% | 42,685 psi | 66% | 2753 fps | 96.1% |
| Vihtavuori N565 | <<locked>> | 84% | 40,582 psi | 62% | 2687 fps | 95.7% |
| Vihtavuori N568 | <<locked>> | 90% | 44,150 psi | 68% | 2795 fps | 95.6% |
| Vihtavuori N570 | <<locked>> | 96% | 51,996 psi | 80% | 2976 fps | 95.9% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 52,794 psi | 81% | 2789 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 36,535 psi | 56% | 2684 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 40,770 psi | 63% | 2635 fps | 97.3% |
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 | 170gr | Swift A-Frame. Hodgdon Retumbo delivers the highest muzzle velocity at 3,097 fps; across all powders the maximum-charge window runs from 1,916 fps to 3,097 fps. ADI AR 2225 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 57–90 %, leaving at least 10 % headroom. The 170.0 gr projectile in 0.308" calls for a 1:6.0 twist; slower twists will usually not stabilise this weight. ADI AR 2225, Alliant Reloder-33, 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 76, Vihtavuori N560 rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 170gr | Swift A-Frame 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.