Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 165gr | Swift Scirocco bullet and 73 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 Winchester StaBALL HD.
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>> | 92% | 55,709 psi | 86% | 2910 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 56,420 psi | 87% | 2946 fps | 100% |
| Accurate MAGPRO | <<locked>> | 92% | 58,610 psi | 90% | 3064 fps | 98.6% |
| ADI AR 2209 | <<locked>> | 90% | 57,392 psi | 88% | 3002 fps | 99.6% |
| ADI AR 2213 | <<locked>> | 92% | 55,332 psi | 85% | 3005 fps | 98.9% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 53,635 psi | 83% | 2959 fps | 99% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 48,211 psi | 74% | 2920 fps | 99.9% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 57,696 psi | 89% | 2999 fps | 99.7% |
| Alliant Reloder-16 | <<locked>> | 86% | 57,334 psi | 88% | 3002 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 82% | 58,639 psi | 90% | 3012 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 57,014 psi | 88% | 2989 fps | 99.6% |
| Alliant Reloder-22 | <<locked>> | 92% | 55,593 psi | 86% | 2999 fps | 99.6% |
| Alliant Reloder-23 | <<locked>> | 94% | 57,130 psi | 88% | 2972 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 56,927 psi | 88% | 3031 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 90% | 58,001 psi | 89% | 3058 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 56,927 psi | 88% | 2956 fps | 96.8% |
| Bofors RP15 | <<locked>> | 96% | 58,711 psi | 90% | 3045 fps | 99.8% |
| Bofors RP30ᴾ | <<locked>> | 100% | 56,681 psi | 87% | 3031 fps | 99.4% |
| Bofors RP5 | <<locked>> | 92% | 55,593 psi | 86% | 2999 fps | 99.6% |
| Bofors RP7 | <<locked>> | 84% | 58,189 psi | 90% | 2946 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 98% | 55,332 psi | 85% | 2992 fps | 99.5% |
| Hodgdon H414 | <<locked>> | 84% | 57,899 psi | 89% | 2995 fps | 100% |
| Hodgdon H4350 | <<locked>> | 82% | 56,550 psi | 87% | 2956 fps | 99.6% |
| Hodgdon H4831 | <<locked>> | 90% | 55,042 psi | 85% | 2940 fps | 98.2% |
| Hodgdon H4831 SC | <<locked>> | 92% | 57,740 psi | 89% | 2982 fps | 98.7% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 57,711 psi | 89% | 2920 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 55,796 psi | 86% | 3107 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 54,853 psi | 84% | 2969 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,144 psi | 57% | 1919 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 56,449 psi | 87% | 2930 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 82% | 55,825 psi | 86% | 2913 fps | 99.9% |
| IMR 4831 | <<locked>> | 86% | 56,637 psi | 87% | 2933 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 55,883 psi | 86% | 2927 fps | 98.5% |
| IMR 7828 SSC | <<locked>> | 94% | 57,232 psi | 88% | 3041 fps | 99.2% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 43,642 psi | 67% | 2822 fps | 96.9% |
| Lovex S065 | <<locked>> | 84% | 56,768 psi | 87% | 2913 fps | 100% |
| Lovex S070 | <<locked>> | 86% | 58,726 psi | 90% | 2963 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 56,985 psi | 88% | 2927 fps | 100% |
| Norma 204 | <<locked>> | 86% | 57,885 psi | 89% | 2986 fps | 99.6% |
| Norma 217ᴾ | <<locked>> | 100% | 43,961 psi | 68% | 2851 fps | 99% |
| Norma MRP | <<locked>> | 90% | 55,709 psi | 86% | 3018 fps | 100% |
| Norma URP | <<locked>> | 86% | 58,407 psi | 90% | 2979 fps | 100% |
| Ramshot Grand | <<locked>> | 94% | 58,523 psi | 90% | 3061 fps | 99.5% |
| Ramshot Hunter | <<locked>> | 86% | 57,522 psi | 89% | 2986 fps | 100% |
| Ramshot Magnum | <<locked>> | 96% | 57,276 psi | 88% | 2992 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,971 psi | 58% | 1962 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 56,579 psi | 87% | 2963 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 55,085 psi | 85% | 2989 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 57,072 psi | 88% | 3100 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 56,478 psi | 87% | 3051 fps | 98.6% |
| Rottweil R 904 | <<locked>> | 90% | 58,334 psi | 90% | 2969 fps | 99.2% |
| Rottweil R 905 | <<locked>> | 90% | 56,434 psi | 87% | 2976 fps | 99.6% |
| Rottweil R 907 | <<locked>> | 84% | 58,189 psi | 90% | 2946 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 84% | 56,768 psi | 87% | 2913 fps | 100% |
| Shooters World SW4350 | <<locked>> | 86% | 58,726 psi | 90% | 2963 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 58,798 psi | 90% | 2808 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 56,028 psi | 86% | 2864 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 55,999 psi | 86% | 2972 fps | 99.6% |
| Somchem S361 | <<locked>> | 88% | 56,318 psi | 87% | 2900 fps | 98.4% |
| Somchem S365 | <<locked>> | 86% | 55,492 psi | 85% | 2927 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 57,101 psi | 88% | 2949 fps | 99.9% |
| Vihtavuori N150 | <<locked>> | 82% | 56,739 psi | 87% | 2854 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 56,333 psi | 87% | 2917 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 56,855 psi | 88% | 2930 fps | 99.8% |
| Vihtavuori N550 | <<locked>> | 84% | 55,651 psi | 86% | 2920 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 55,347 psi | 85% | 2946 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 55,376 psi | 85% | 3015 fps | 98.5% |
| Vihtavuori N565 | <<locked>> | 96% | 55,695 psi | 86% | 2995 fps | 98.8% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 57,058 psi | 88% | 3058 fps | 98.2% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 56,057 psi | 86% | 2867 fps | 100% |
| Winchester 760 | <<locked>> | 84% | 58,102 psi | 89% | 2999 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 55,854 psi | 86% | 3051 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 57,203 psi | 88% | 2946 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% | 36,840 psi | 57% | 2579 fps | 98% |
| Accurate 4350 | <<locked>> | 80% | 49,081 psi | 76% | 2835 fps | 100% |
| Accurate MAGPRO | <<locked>> | 84% | 43,830 psi | 67% | 2805 fps | 95.1% |
| ADI AR 2209 | <<locked>> | 80% | 40,785 psi | 63% | 2707 fps | 96.6% |
| ADI AR 2213 | <<locked>> | 84% | 41,974 psi | 65% | 2756 fps | 95.7% |
| ADI AR 2217 | <<locked>> | 92% | 40,712 psi | 63% | 2720 fps | 95.7% |
| ADI AR 2225 | <<locked>> | 88% | 32,227 psi | 50% | 2556 fps | 95.4% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 41,205 psi | 63% | 2707 fps | 96.7% |
| Alliant Reloder-16 | <<locked>> | 80% | 46,891 psi | 72% | 2841 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 54,491 psi | 84% | 2956 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 40,828 psi | 63% | 2700 fps | 96.7% |
| Alliant Reloder-22 | <<locked>> | 80% | 36,738 psi | 57% | 2641 fps | 95.3% |
| Alliant Reloder-23 | <<locked>> | 80% | 35,389 psi | 54% | 2608 fps | 99.8% |
| Alliant Reloder-25 | <<locked>> | 80% | 30,705 psi | 47% | 2513 fps | 96.5% |
| Alliant Reloder-26 | <<locked>> | 80% | 39,479 psi | 61% | 2749 fps | 99.6% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 50,169 psi | 77% | 2844 fps | 95.1% |
| Bofors RP15 | <<locked>> | 82% | 36,535 psi | 56% | 2635 fps | 95.1% |
| Bofors RP30 | <<locked>> | 90% | 40,074 psi | 62% | 2733 fps | 95.8% |
| Bofors RP5 | <<locked>> | 80% | 36,738 psi | 57% | 2641 fps | 95.3% |
| Bofors RP7 | <<locked>> | 80% | 51,111 psi | 79% | 2838 fps | 99.4% |
| Hodgdon H1000 | <<locked>> | 88% | 38,812 psi | 60% | 2680 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 80% | 50,589 psi | 78% | 2881 fps | 99.7% |
| Hodgdon H4350 | <<locked>> | 80% | 52,924 psi | 81% | 2897 fps | 99.3% |
| Hodgdon H4831 | <<locked>> | 84% | 44,802 psi | 69% | 2762 fps | 95.9% |
| Hodgdon H4831 SC | <<locked>> | 84% | 44,005 psi | 68% | 2746 fps | 95.7% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 44,179 psi | 68% | 2723 fps | 100% |
| Hodgdon Retumbo | 80.1 gr | 86% | 36,767 psi | 57% | 2717 fps | 96.1% |
| Hodgdon Superformance | <<locked>> | 80% | 50,952 psi | 78% | 2910 fps | 99.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,862 psi | 43% | 1722 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 46,557 psi | 72% | 2766 fps | 98.9% |
| IMR 4451 Enduron | <<locked>> | 80% | 52,446 psi | 81% | 2861 fps | 99.7% |
| IMR 4831 | <<locked>> | 80% | 46,499 psi | 72% | 2779 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 82% | 43,163 psi | 66% | 2700 fps | 95.6% |
| IMR 7828 SSC | <<locked>> | 84% | 40,277 psi | 62% | 2730 fps | 95.2% |
| IMR 8133 Enduron | <<locked>> | 98% | 40,741 psi | 63% | 2762 fps | 96% |
| Lovex S065 | <<locked>> | 80% | 50,067 psi | 77% | 2808 fps | 99.9% |
| Lovex S070 | <<locked>> | 80% | 48,486 psi | 75% | 2802 fps | 99.5% |
| Lovex S071 | <<locked>> | 80% | 31,662 psi | 49% | 2454 fps | 96.1% |
| Norma 204 | <<locked>> | 80% | 46,905 psi | 72% | 2805 fps | 98% |
| Norma 217 | <<locked>> | 92% | 33,199 psi | 51% | 2602 fps | 95.2% |
| Norma MRP | <<locked>> | 80% | 38,667 psi | 60% | 2710 fps | 97.5% |
| Norma URP | <<locked>> | 80% | 47,892 psi | 74% | 2822 fps | 100% |
| Ramshot Grand | <<locked>> | 84% | 40,190 psi | 62% | 2740 fps | 95.6% |
| Ramshot Hunter | <<locked>> | 80% | 46,833 psi | 72% | 2815 fps | 99.7% |
| Ramshot Magnum | <<locked>> | 82% | 33,504 psi | 52% | 2552 fps | 95% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,529 psi | 44% | 1765 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 49,139 psi | 76% | 2851 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 47,398 psi | 73% | 2871 fps | 100% |
| ReloadSwiss RS 76 | 83.7 gr | 84% | 33,663 psi | 52% | 2625 fps | 96% |
| ReloadSwiss RS 80 | <<locked>> | 94% | 44,570 psi | 69% | 2848 fps | 95.8% |
| Rottweil R 904 | <<locked>> | 80% | 42,090 psi | 65% | 2690 fps | 95.9% |
| Rottweil R 905 | <<locked>> | 80% | 40,161 psi | 62% | 2687 fps | 96.6% |
| Rottweil R 907 | <<locked>> | 80% | 51,111 psi | 79% | 2838 fps | 99.4% |
| Shooters World Long Rifle | <<locked>> | 80% | 50,067 psi | 77% | 2808 fps | 99.9% |
| Shooters World SW4350 | <<locked>> | 80% | 48,486 psi | 75% | 2802 fps | 99.5% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 55,361 psi | 85% | 2766 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 49,168 psi | 76% | 2759 fps | 99.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 39,813 psi | 61% | 2684 fps | 96.5% |
| Somchem S361 | <<locked>> | 80% | 42,917 psi | 66% | 2671 fps | 95.4% |
| Somchem S365 | <<locked>> | 80% | 45,121 psi | 69% | 2776 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 40,799 psi | 63% | 2671 fps | 97.6% |
| Vihtavuori N150 | <<locked>> | 80% | 53,229 psi | 82% | 2808 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 49,298 psi | 76% | 2815 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 35,404 psi | 54% | 2539 fps | 95.5% |
| Vihtavuori N550 | <<locked>> | 80% | 48,733 psi | 75% | 2815 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 39,697 psi | 61% | 2687 fps | 99.8% |
| Vihtavuori N560 | <<locked>> | 82% | 41,684 psi | 64% | 2762 fps | 95.1% |
| Vihtavuori N565 | <<locked>> | 88% | 42,148 psi | 65% | 2753 fps | 95.6% |
| Vihtavuori N568 | <<locked>> | 94% | 45,585 psi | 70% | 2858 fps | 95.4% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 48,689 psi | 75% | 2766 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 50,778 psi | 78% | 2884 fps | 99.7% |
| Winchester StaBALL HD | 76.5 gr | 80% | 31,836 psi | 49% | 2628 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 37,405 psi | 58% | 2592 fps | 95.6% |
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 73 powders for .300 Rem. Ultra Mag. loaded with the .308 | 165gr | Swift Scirocco. Hodgdon Retumbo delivers the highest muzzle velocity at 3,107 fps; across all powders the maximum-charge window runs from 1,919 fps to 3,107 fps. ADI AR 2217 gives the best case fill at 100 %, and 73 of the 73 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 165.0 gr projectile in 0.308" calls for a 1:11.5 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Bofors RP30 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, Winchester StaBALL HD rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 165gr | Swift Scirocco 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.