Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 165gr | Sierra SBT GameKing 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% | 57,986 psi | 89% | 2943 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 58,624 psi | 90% | 2976 fps | 100% |
| Accurate MAGPRO | <<locked>> | 90% | 56,855 psi | 88% | 3038 fps | 98.5% |
| ADI AR 2209 | <<locked>> | 88% | 55,622 psi | 86% | 2976 fps | 99.6% |
| ADI AR 2213 | <<locked>> | 92% | 57,754 psi | 89% | 3041 fps | 99.3% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 55,956 psi | 86% | 3002 fps | 99.4% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 50,575 psi | 78% | 2963 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 55,927 psi | 86% | 2976 fps | 99.6% |
| Alliant Reloder-16 | <<locked>> | 84% | 55,695 psi | 86% | 2979 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 55,303 psi | 85% | 2966 fps | 99.6% |
| Alliant Reloder-22 | <<locked>> | 92% | 58,059 psi | 89% | 3038 fps | 99.8% |
| Alliant Reloder-23 | <<locked>> | 92% | 55,695 psi | 86% | 2953 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 55,709 psi | 86% | 3012 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 56,420 psi | 87% | 3035 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 53,679 psi | 83% | 3015 fps | 96.3% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 58,755 psi | 90% | 2992 fps | 97.5% |
| Bofors RP15 | <<locked>> | 94% | 57,217 psi | 88% | 3022 fps | 99.7% |
| Bofors RP30 | <<locked>> | 98% | 55,579 psi | 86% | 3015 fps | 99.4% |
| Bofors RP5 | <<locked>> | 92% | 58,059 psi | 89% | 3038 fps | 99.8% |
| Bofors RP7 | <<locked>> | 82% | 56,217 psi | 87% | 2920 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 98% | 57,783 psi | 89% | 3028 fps | 99.8% |
| Hodgdon H414 | <<locked>> | 82% | 56,144 psi | 86% | 2972 fps | 100% |
| Hodgdon H4350 | <<locked>> | 82% | 58,378 psi | 90% | 2986 fps | 99.8% |
| Hodgdon H4831 | <<locked>> | 90% | 57,174 psi | 88% | 2976 fps | 98.7% |
| Hodgdon H4831 SC | <<locked>> | 90% | 55,999 psi | 86% | 2956 fps | 98.6% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 55,927 psi | 86% | 2900 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 58,508 psi | 90% | 3150 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 57,130 psi | 88% | 3005 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,304 psi | 57% | 1932 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 58,291 psi | 90% | 2959 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 57,522 psi | 89% | 2943 fps | 100% |
| IMR 4831 | <<locked>> | 86% | 58,697 psi | 90% | 2963 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 57,682 psi | 89% | 2959 fps | 98.9% |
| IMR 7828 SSC | <<locked>> | 92% | 55,767 psi | 86% | 3022 fps | 99.1% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 46,035 psi | 71% | 2867 fps | 97.8% |
| Lovex S065 | <<locked>> | 84% | 58,523 psi | 90% | 2940 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 56,927 psi | 88% | 2940 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 55,767 psi | 86% | 2910 fps | 100% |
| Norma 204 | <<locked>> | 84% | 55,927 psi | 86% | 2963 fps | 99.5% |
| Norma 217ᴾ | <<locked>> | 100% | 46,528 psi | 72% | 2894 fps | 99.4% |
| Norma MRP | <<locked>> | 90% | 58,247 psi | 90% | 3058 fps | 100% |
| Norma URP | <<locked>> | 84% | 56,666 psi | 87% | 2959 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 56,884 psi | 88% | 3041 fps | 99.5% |
| Ramshot Hunter | <<locked>> | 84% | 55,724 psi | 86% | 2959 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 55,521 psi | 85% | 2969 fps | 99.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,145 psi | 59% | 1975 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 58,798 psi | 90% | 2995 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 57,377 psi | 88% | 3025 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 55,738 psi | 86% | 3077 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 55,042 psi | 85% | 3028 fps | 98.5% |
| Rottweil R 904 | <<locked>> | 88% | 56,536 psi | 87% | 2946 fps | 99.1% |
| Rottweil R 905 | <<locked>> | 88% | 54,969 psi | 85% | 2956 fps | 99.6% |
| Rottweil R 907 | <<locked>> | 82% | 56,217 psi | 87% | 2920 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 84% | 58,523 psi | 90% | 2940 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 56,927 psi | 88% | 2940 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 57,638 psi | 89% | 2894 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 58,392 psi | 90% | 3012 fps | 99.8% |
| Somchem S361 | <<locked>> | 88% | 58,363 psi | 90% | 2933 fps | 98.9% |
| Somchem S365 | <<locked>> | 86% | 57,725 psi | 89% | 2956 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 55,390 psi | 85% | 2927 fps | 99.9% |
| Vihtavuori N150 | <<locked>> | 82% | 58,624 psi | 90% | 2881 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 58,378 psi | 90% | 2946 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 55,201 psi | 85% | 2907 fps | 99.8% |
| Vihtavuori N550 | <<locked>> | 84% | 57,609 psi | 89% | 2949 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 57,667 psi | 89% | 2979 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 57,783 psi | 89% | 3054 fps | 99% |
| Vihtavuori N565 | <<locked>> | 96% | 58,407 psi | 90% | 3035 fps | 99.2% |
| Vihtavuori N568 | <<locked>> | 98% | 55,709 psi | 86% | 3035 fps | 98.1% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 56,797 psi | 87% | 3094 fps | 96.6% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 58,160 psi | 90% | 2894 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 56,347 psi | 87% | 2976 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 54,737 psi | 84% | 3031 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 55,390 psi | 85% | 2923 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% | 38,348 psi | 59% | 2612 fps | 98.5% |
| Accurate 4350 | <<locked>> | 80% | 50,937 psi | 78% | 2867 fps | 100% |
| Accurate MAGPRO | <<locked>> | 84% | 45,759 psi | 70% | 2844 fps | 96% |
| ADI AR 2209 | <<locked>> | 80% | 42,308 psi | 65% | 2743 fps | 97.3% |
| ADI AR 2213 | <<locked>> | 82% | 40,625 psi | 63% | 2730 fps | 95.5% |
| ADI AR 2217 | <<locked>> | 90% | 39,639 psi | 61% | 2697 fps | 95.5% |
| ADI AR 2225 | <<locked>> | 86% | 31,401 psi | 48% | 2533 fps | 95.2% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 42,728 psi | 66% | 2743 fps | 97.4% |
| Alliant Reloder-16 | <<locked>> | 80% | 48,559 psi | 75% | 2871 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 42,337 psi | 65% | 2736 fps | 97.3% |
| Alliant Reloder-22 | <<locked>> | 80% | 38,377 psi | 59% | 2680 fps | 96.2% |
| Alliant Reloder-23 | <<locked>> | 80% | 37,014 psi | 57% | 2641 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 31,966 psi | 49% | 2549 fps | 97.3% |
| Alliant Reloder-26 | <<locked>> | 80% | 41,481 psi | 64% | 2789 fps | 99.8% |
| Alliant Reloder-33 | <<locked>> | 98% | 49,617 psi | 76% | 2943 fps | 95.2% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 51,822 psi | 80% | 2877 fps | 95.9% |
| Bofors RP15 | <<locked>> | 82% | 38,159 psi | 59% | 2671 fps | 95.9% |
| Bofors RP30 | <<locked>> | 88% | 39,146 psi | 60% | 2713 fps | 95.7% |
| Bofors RP5 | <<locked>> | 80% | 38,377 psi | 59% | 2680 fps | 96.2% |
| Bofors RP7 | <<locked>> | 80% | 52,678 psi | 81% | 2867 fps | 99.7% |
| Hodgdon H1000 | <<locked>> | 86% | 37,739 psi | 58% | 2657 fps | 95.5% |
| Hodgdon H414 | <<locked>> | 80% | 52,431 psi | 81% | 2913 fps | 99.8% |
| Hodgdon H4350 | <<locked>> | 80% | 54,708 psi | 84% | 2930 fps | 99.6% |
| Hodgdon H4831 | <<locked>> | 82% | 43,337 psi | 67% | 2736 fps | 95.7% |
| Hodgdon H4831 SC | <<locked>> | 82% | 42,540 psi | 65% | 2720 fps | 95.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 45,759 psi | 70% | 2749 fps | 100% |
| Hodgdon Retumbo | 80.9 gr | 84% | 35,839 psi | 55% | 2697 fps | 95.9% |
| Hodgdon Superformance | <<locked>> | 80% | 53,040 psi | 82% | 2943 fps | 99.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,891 psi | 43% | 1736 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 48,080 psi | 74% | 2799 fps | 99.2% |
| IMR 4451 Enduron | <<locked>> | 80% | 53,998 psi | 83% | 2890 fps | 99.9% |
| IMR 4831 | <<locked>> | 80% | 48,167 psi | 74% | 2805 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 41,843 psi | 64% | 2677 fps | 95.4% |
| IMR 7828 SSC | <<locked>> | 82% | 39,218 psi | 60% | 2707 fps | 95% |
| IMR 8133 Enduron | <<locked>> | 96% | 40,074 psi | 62% | 2749 fps | 95.9% |
| Lovex S065 | <<locked>> | 80% | 51,692 psi | 80% | 2841 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 50,067 psi | 77% | 2831 fps | 99.7% |
| Lovex S071 | <<locked>> | 80% | 33,011 psi | 51% | 2490 fps | 96.9% |
| Norma 204 | <<locked>> | 80% | 48,588 psi | 75% | 2841 fps | 98.5% |
| Norma 217 | <<locked>> | 90% | 32,634 psi | 50% | 2589 fps | 95.2% |
| Norma MRP | <<locked>> | 80% | 40,538 psi | 62% | 2749 fps | 98.2% |
| Norma URP | <<locked>> | 80% | 49,617 psi | 76% | 2851 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 39,059 psi | 60% | 2713 fps | 95.4% |
| Ramshot Hunter | <<locked>> | 80% | 48,559 psi | 75% | 2848 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 82% | 35,027 psi | 54% | 2589 fps | 96% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,543 psi | 44% | 1775 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 51,169 psi | 79% | 2884 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 49,429 psi | 76% | 2904 fps | 100% |
| ReloadSwiss RS 76 | 84.5 gr | 82% | 32,764 psi | 50% | 2598 fps | 95.8% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 43,511 psi | 67% | 2825 fps | 95.6% |
| Rottweil R 904 | <<locked>> | 80% | 43,395 psi | 67% | 2720 fps | 96.5% |
| Rottweil R 905 | <<locked>> | 80% | 41,727 psi | 64% | 2723 fps | 97.3% |
| Rottweil R 907 | <<locked>> | 80% | 52,678 psi | 81% | 2867 fps | 99.7% |
| Shooters World Long Rifle | <<locked>> | 80% | 51,692 psi | 80% | 2841 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 50,067 psi | 77% | 2831 fps | 99.7% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 50,618 psi | 78% | 2789 fps | 99.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 41,379 psi | 64% | 2717 fps | 97.2% |
| Somchem S361 | <<locked>> | 80% | 44,454 psi | 68% | 2703 fps | 96.1% |
| Somchem S365 | <<locked>> | 80% | 46,978 psi | 72% | 2805 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 42,438 psi | 65% | 2703 fps | 98.2% |
| Vihtavuori N150 | <<locked>> | 80% | 54,897 psi | 84% | 2835 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 50,995 psi | 78% | 2841 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 36,782 psi | 57% | 2572 fps | 96.3% |
| Vihtavuori N550 | <<locked>> | 80% | 50,488 psi | 78% | 2844 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 41,307 psi | 64% | 2717 fps | 99.9% |
| Vihtavuori N560 | <<locked>> | 82% | 43,497 psi | 67% | 2802 fps | 95.9% |
| Vihtavuori N565 | <<locked>> | 86% | 41,162 psi | 63% | 2733 fps | 95.5% |
| Vihtavuori N568 | <<locked>> | 92% | 44,527 psi | 69% | 2835 fps | 95.2% |
| Vihtavuori N570 | <<locked>> | 98% | 52,721 psi | 81% | 3025 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 50,604 psi | 78% | 2792 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 52,605 psi | 81% | 2917 fps | 99.9% |
| Winchester StaBALL HD | 79.1 gr | 80% | 33,837 psi | 52% | 2667 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 38,885 psi | 60% | 2628 fps | 96.3% |
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 73 powders for .300 Rem. Ultra Mag. loaded with the .308 | 165gr | Sierra SBT GameKing. Hodgdon Retumbo delivers the highest muzzle velocity at 3,150 fps; across all powders the maximum-charge window runs from 1,932 fps to 3,150 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 1:13.5 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, Winchester StaBALL HD rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 165gr | Sierra SBT GameKing 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.