Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 180gr | Winchester FailSafe bullet and 70 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% | 56,362 psi | 87% | 2818 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 56,753 psi | 87% | 2844 fps | 100% |
| Accurate MAGPRO | <<locked>> | 88% | 55,158 psi | 85% | 2913 fps | 98.7% |
| ADI AR 2209 | <<locked>> | 88% | 57,798 psi | 89% | 2907 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 90% | 55,941 psi | 86% | 2913 fps | 99.5% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 58,291 psi | 90% | 2940 fps | 99.9% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 50,894 psi | 78% | 2904 fps | 96.2% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 52,707 psi | 81% | 2900 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 57,870 psi | 89% | 2904 fps | 99.9% |
| Alliant Reloder-16 | <<locked>> | 84% | 57,711 psi | 89% | 2897 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 57,203 psi | 88% | 2894 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 90% | 56,333 psi | 87% | 2913 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 92% | 57,957 psi | 89% | 2874 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 58,030 psi | 89% | 2943 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 86% | 54,795 psi | 84% | 2907 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 56,246 psi | 87% | 2966 fps | 97.6% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 56,811 psi | 87% | 2871 fps | 97.7% |
| Bofors RP15 | <<locked>> | 92% | 55,521 psi | 85% | 2897 fps | 99.8% |
| Bofors RP30 | <<locked>> | 98% | 57,943 psi | 89% | 2953 fps | 99.8% |
| Bofors RP5 | <<locked>> | 90% | 56,333 psi | 87% | 2913 fps | 99.9% |
| Bofors RP7 | <<locked>> | 82% | 58,015 psi | 89% | 2844 fps | 100% |
| Hodgdon H1000 | <<locked>> | 96% | 55,985 psi | 86% | 2907 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 82% | 58,131 psi | 89% | 2897 fps | 100% |
| Hodgdon H4831 | <<locked>> | 88% | 55,259 psi | 85% | 2851 fps | 99% |
| Hodgdon H4831 SC | <<locked>> | 90% | 58,102 psi | 89% | 2890 fps | 99.3% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 57,928 psi | 89% | 2818 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 56,985 psi | 88% | 3022 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,492 psi | 58% | 1854 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 56,405 psi | 87% | 2831 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 56,913 psi | 88% | 2835 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 55,985 psi | 86% | 2835 fps | 99.1% |
| IMR 7828 SSC | <<locked>> | 92% | 58,001 psi | 89% | 2953 fps | 99.7% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 48,240 psi | 74% | 2815 fps | 98.8% |
| Lovex S065 | <<locked>> | 82% | 56,652 psi | 87% | 2812 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 58,697 psi | 90% | 2861 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 57,798 psi | 89% | 2838 fps | 100% |
| Norma 204 | <<locked>> | 84% | 57,769 psi | 89% | 2887 fps | 99.9% |
| Norma 217ᴾ | <<locked>> | 100% | 48,907 psi | 75% | 2838 fps | 99.9% |
| Norma MRP | <<locked>> | 88% | 56,434 psi | 87% | 2927 fps | 100% |
| Norma URP | <<locked>> | 84% | 58,595 psi | 90% | 2877 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 55,100 psi | 85% | 2913 fps | 99.6% |
| Ramshot Hunter | <<locked>> | 84% | 57,609 psi | 89% | 2884 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 57,986 psi | 89% | 2904 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,392 psi | 59% | 1896 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 57,043 psi | 88% | 2867 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 55,463 psi | 85% | 2890 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 58,189 psi | 90% | 3012 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 57,566 psi | 89% | 2972 fps | 99.3% |
| Rottweil R 904 | <<locked>> | 88% | 58,291 psi | 90% | 2874 fps | 99.6% |
| Rottweil R 905 | <<locked>> | 88% | 56,956 psi | 88% | 2887 fps | 99.9% |
| Rottweil R 907 | <<locked>> | 82% | 58,015 psi | 89% | 2844 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 82% | 56,652 psi | 87% | 2812 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 58,697 psi | 90% | 2861 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 55,811 psi | 86% | 2769 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 56,536 psi | 87% | 2881 fps | 99.9% |
| Somchem S361 | <<locked>> | 86% | 56,318 psi | 87% | 2812 fps | 99.1% |
| Somchem S365 | <<locked>> | 84% | 56,028 psi | 86% | 2828 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 57,377 psi | 88% | 2854 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 56,492 psi | 87% | 2818 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 57,130 psi | 88% | 2838 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 55,869 psi | 86% | 2825 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 56,188 psi | 86% | 2854 fps | 100% |
| Vihtavuori N560 | <<locked>> | 88% | 55,912 psi | 86% | 2927 fps | 99.2% |
| Vihtavuori N565 | <<locked>> | 94% | 56,623 psi | 87% | 2913 fps | 99.4% |
| Vihtavuori N568 | <<locked>> | 98% | 58,189 psi | 90% | 2979 fps | 99% |
| Vihtavuori N570 | <<locked>> | 98% | 55,172 psi | 85% | 2969 fps | 97% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 56,014 psi | 86% | 2766 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 58,334 psi | 90% | 2900 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 57,653 psi | 89% | 2963 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 57,363 psi | 88% | 2851 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% | 40,016 psi | 62% | 2556 fps | 99.3% |
| Accurate 4350 | <<locked>> | 80% | 52,895 psi | 81% | 2792 fps | 100% |
| Accurate MAGPRO | <<locked>> | 80% | 41,292 psi | 64% | 2664 fps | 95.4% |
| ADI AR 2209 | <<locked>> | 80% | 43,976 psi | 68% | 2680 fps | 98.3% |
| ADI AR 2213 | <<locked>> | 80% | 39,334 psi | 61% | 2612 fps | 95.9% |
| ADI AR 2217 | <<locked>> | 86% | 35,998 psi | 55% | 2530 fps | 95% |
| ADI AR 2218 | <<locked>> | 98% | 47,427 psi | 73% | 2835 fps | 95% |
| ADI AR 2225 | <<locked>> | 84% | 30,632 psi | 47% | 2434 fps | 95.8% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 44,338 psi | 68% | 2680 fps | 98.4% |
| Alliant Reloder-16 | <<locked>> | 80% | 50,575 psi | 78% | 2799 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 43,976 psi | 68% | 2674 fps | 98.3% |
| Alliant Reloder-22 | <<locked>> | 80% | 39,929 psi | 61% | 2621 fps | 97.5% |
| Alliant Reloder-23 | <<locked>> | 80% | 38,696 psi | 60% | 2579 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 33,388 psi | 51% | 2503 fps | 98.6% |
| Alliant Reloder-26 | <<locked>> | 80% | 43,453 psi | 67% | 2730 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 96% | 48,138 psi | 74% | 2828 fps | 95.6% |
| Baschieri & Pellagri 109 | <<locked>> | 86% | 47,007 psi | 72% | 2703 fps | 95.3% |
| Bofors RP15 | <<locked>> | 80% | 37,188 psi | 57% | 2562 fps | 96.4% |
| Bofors RP30 | <<locked>> | 84% | 35,650 psi | 55% | 2546 fps | 95.2% |
| Bofors RP5 | <<locked>> | 80% | 39,929 psi | 61% | 2621 fps | 97.5% |
| Bofors RP7 | <<locked>> | 80% | 54,273 psi | 84% | 2792 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 84% | 36,564 psi | 56% | 2546 fps | 96% |
| Hodgdon H414 | <<locked>> | 80% | 54,389 psi | 84% | 2844 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 41,959 psi | 65% | 2618 fps | 96.1% |
| Hodgdon H4831 SC | <<locked>> | 80% | 41,191 psi | 63% | 2602 fps | 95.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 47,616 psi | 73% | 2677 fps | 100% |
| Hodgdon Retumbo | 75.3 gr | 80% | 32,561 psi | 50% | 2523 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,992 psi | 43% | 1660 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 49,690 psi | 76% | 2730 fps | 99.7% |
| IMR 4831 | <<locked>> | 80% | 49,951 psi | 77% | 2736 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 43,236 psi | 67% | 2615 fps | 96.7% |
| IMR 7828 SSC | <<locked>> | 80% | 38,000 psi | 58% | 2592 fps | 95.5% |
| IMR 8133 Enduron | <<locked>> | 92% | 36,535 psi | 56% | 2582 fps | 95.4% |
| Lovex S065 | <<locked>> | 80% | 53,258 psi | 82% | 2762 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 51,721 psi | 80% | 2759 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 34,374 psi | 53% | 2434 fps | 98% |
| Norma 204 | <<locked>> | 80% | 50,488 psi | 78% | 2776 fps | 99.3% |
| Norma 217 | <<locked>> | 88% | 31,923 psi | 49% | 2487 fps | 95.8% |
| Norma MRP | <<locked>> | 80% | 42,337 psi | 65% | 2694 fps | 99.1% |
| Norma URP | <<locked>> | 80% | 51,416 psi | 79% | 2776 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 37,840 psi | 58% | 2598 fps | 95.9% |
| Ramshot Hunter | <<locked>> | 80% | 50,459 psi | 78% | 2779 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 34,026 psi | 52% | 2484 fps | 96.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,703 psi | 44% | 1699 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 53,142 psi | 82% | 2812 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 51,561 psi | 79% | 2835 fps | 100% |
| ReloadSwiss RS 76 | 80.6 gr | 80% | 31,821 psi | 49% | 2497 fps | 96.3% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 42,206 psi | 65% | 2710 fps | 96% |
| Rottweil R 904 | <<locked>> | 80% | 45,063 psi | 69% | 2661 fps | 97.7% |
| Rottweil R 905 | <<locked>> | 80% | 43,395 psi | 67% | 2661 fps | 98.4% |
| Rottweil R 907 | <<locked>> | 80% | 54,273 psi | 84% | 2792 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 80% | 53,258 psi | 82% | 2762 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 51,721 psi | 80% | 2759 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 52,257 psi | 80% | 2717 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 43,062 psi | 66% | 2657 fps | 98.3% |
| Somchem S361 | <<locked>> | 80% | 45,992 psi | 71% | 2644 fps | 97.3% |
| Somchem S365 | <<locked>> | 80% | 48,921 psi | 75% | 2730 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 43,961 psi | 68% | 2641 fps | 99% |
| Vihtavuori N160 | <<locked>> | 80% | 52,837 psi | 81% | 2769 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 38,276 psi | 59% | 2520 fps | 97.5% |
| Vihtavuori N550 | <<locked>> | 80% | 52,141 psi | 80% | 2769 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 43,033 psi | 66% | 2651 fps | 100% |
| Vihtavuori N560 | 78.2 gr | 80% | 42,177 psi | 65% | 2684 fps | 96.4% |
| Vihtavuori N565 | <<locked>> | 82% | 37,420 psi | 58% | 2562 fps | 95% |
| Vihtavuori N568 | <<locked>> | 90% | 43,395 psi | 67% | 2726 fps | 95.7% |
| Vihtavuori N570 | <<locked>> | 96% | 51,155 psi | 79% | 2904 fps | 96% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 52,272 psi | 80% | 2717 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 54,389 psi | 84% | 2844 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 36,056 psi | 55% | 2618 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 40,379 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 70 powders for .300 Rem. Ultra Mag. loaded with the .308 | 180gr | Winchester FailSafe. Hodgdon Retumbo delivers the highest muzzle velocity at 3,022 fps; across all powders the maximum-charge window runs from 1,854 fps to 3,022 fps. ADI AR 2217 gives the best case fill at 100 %, and 70 of the 70 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 1:13.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2218, ADI AR 2225 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 | Winchester FailSafe 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.