Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 155gr | Berger BT Target bullet and 74 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Hodgdon Retumbo, Winchester StaBALL HD and IMR 7828 SSC.
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% | 54,955 psi | 85% | 2969 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 55,564 psi | 86% | 3009 fps | 100% |
| Accurate MAGPRO | <<locked>> | 92% | 57,885 psi | 89% | 3120 fps | 98.1% |
| ADI AR 2209 | <<locked>> | 90% | 56,710 psi | 87% | 3064 fps | 99.4% |
| ADI AR 2213 | <<locked>> | 94% | 58,653 psi | 90% | 3123 fps | 99% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 52,953 psi | 81% | 3015 fps | 98.5% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 47,659 psi | 73% | 2976 fps | 99.7% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 56,840 psi | 87% | 3058 fps | 99.4% |
| Alliant Reloder-16 | <<locked>> | 86% | 56,492 psi | 87% | 3068 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 82% | 57,711 psi | 89% | 3077 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 56,159 psi | 86% | 3048 fps | 99.3% |
| Alliant Reloder-22 | <<locked>> | 92% | 54,955 psi | 85% | 3058 fps | 99.3% |
| Alliant Reloder-23 | <<locked>> | 94% | 56,275 psi | 87% | 3035 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 55,956 psi | 86% | 3091 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 90% | 57,261 psi | 88% | 3120 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 56,376 psi | 87% | 3015 fps | 96.3% |
| Bofors RP15 | <<locked>> | 96% | 57,696 psi | 89% | 3100 fps | 99.5% |
| Bofors RP30ᴾ | <<locked>> | 100% | 55,825 psi | 86% | 3087 fps | 99.1% |
| Bofors RP5 | <<locked>> | 92% | 54,955 psi | 85% | 3058 fps | 99.3% |
| Bofors RP7 | <<locked>> | 84% | 57,377 psi | 88% | 3009 fps | 99.8% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 58,682 psi | 90% | 3107 fps | 99.6% |
| Hodgdon H414 | <<locked>> | 84% | 57,232 psi | 88% | 3061 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 82% | 55,883 psi | 86% | 3018 fps | 99.4% |
| Hodgdon H4831 | <<locked>> | 92% | 58,392 psi | 90% | 3061 fps | 98.4% |
| Hodgdon H4831 SC | <<locked>> | 92% | 57,130 psi | 88% | 3041 fps | 98.3% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 56,840 psi | 87% | 2986 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 55,027 psi | 85% | 3163 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 84% | 58,378 psi | 90% | 3094 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,144 psi | 57% | 1982 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 55,840 psi | 86% | 2992 fps | 99.7% |
| IMR 4451 Enduron | <<locked>> | 82% | 55,288 psi | 85% | 2979 fps | 99.8% |
| IMR 4831 | <<locked>> | 86% | 56,014 psi | 86% | 2999 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 55,317 psi | 85% | 2986 fps | 98.1% |
| IMR 7828 SSC | <<locked>> | 94% | 56,463 psi | 87% | 3097 fps | 98.8% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 42,989 psi | 66% | 2871 fps | 96.2% |
| Lovex S065 | <<locked>> | 84% | 56,130 psi | 86% | 2979 fps | 100% |
| Lovex S070 | <<locked>> | 86% | 57,943 psi | 89% | 3025 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 56,347 psi | 87% | 2989 fps | 100% |
| Norma 204 | <<locked>> | 86% | 57,058 psi | 88% | 3048 fps | 99.3% |
| Norma 217ᴾ | <<locked>> | 100% | 43,265 psi | 67% | 2900 fps | 98.5% |
| Norma MRP | <<locked>> | 90% | 54,955 psi | 85% | 3081 fps | 99.9% |
| Norma URP | <<locked>> | 86% | 57,566 psi | 89% | 3045 fps | 100% |
| Ramshot Grand | <<locked>> | 94% | 57,725 psi | 89% | 3123 fps | 99.2% |
| Ramshot Hunter | <<locked>> | 86% | 56,739 psi | 87% | 3045 fps | 100% |
| Ramshot Magnum | <<locked>> | 96% | 56,347 psi | 87% | 3048 fps | 99.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,927 psi | 58% | 2028 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 55,753 psi | 86% | 3025 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 86% | 58,479 psi | 90% | 3114 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 56,115 psi | 86% | 3156 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 55,579 psi | 86% | 3104 fps | 98.1% |
| Rottweil R 904 | <<locked>> | 90% | 57,551 psi | 89% | 3031 fps | 98.8% |
| Rottweil R 905 | <<locked>> | 90% | 55,796 psi | 86% | 3041 fps | 99.4% |
| Rottweil R 907 | <<locked>> | 84% | 57,377 psi | 88% | 3009 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 84% | 56,130 psi | 86% | 2979 fps | 100% |
| Shooters World SW4350 | <<locked>> | 86% | 57,943 psi | 89% | 3025 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 58,262 psi | 90% | 2881 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 55,332 psi | 85% | 2927 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 55,361 psi | 85% | 3035 fps | 99.3% |
| Somchem S355 | <<locked>> | 82% | 58,392 psi | 90% | 3002 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 55,753 psi | 86% | 2959 fps | 98% |
| Somchem S365 | <<locked>> | 88% | 58,668 psi | 90% | 3045 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 56,405 psi | 87% | 3012 fps | 99.8% |
| Vihtavuori N150 | <<locked>> | 82% | 56,188 psi | 86% | 2923 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 55,608 psi | 86% | 2982 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 56,028 psi | 86% | 2986 fps | 99.6% |
| Vihtavuori N550 | <<locked>> | 86% | 58,726 psi | 90% | 3038 fps | 100% |
| Vihtavuori N555 | <<locked>> | 92% | 58,334 psi | 90% | 3064 fps | 100% |
| Vihtavuori N560 | <<locked>> | 92% | 58,465 psi | 90% | 3133 fps | 98.7% |
| Vihtavuori N565 | <<locked>> | 96% | 54,955 psi | 85% | 3048 fps | 98.4% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 56,159 psi | 86% | 3107 fps | 97.6% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 55,434 psi | 85% | 2933 fps | 100% |
| Winchester 760 | <<locked>> | 84% | 57,421 psi | 88% | 3064 fps | 99.9% |
| Winchester StaBALL HD | <<locked>> | 94% | 54,955 psi | 85% | 3114 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 56,347 psi | 87% | 3002 fps | 99.4% |
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% | 36,230 psi | 56% | 2628 fps | 97.3% |
| Accurate 4350 | <<locked>> | 80% | 48,341 psi | 74% | 2897 fps | 100% |
| Accurate MAGPRO | <<locked>> | 86% | 46,456 psi | 71% | 2920 fps | 95.4% |
| ADI AR 2209 | <<locked>> | 80% | 40,176 psi | 62% | 2759 fps | 95.9% |
| ADI AR 2213 | <<locked>> | 86% | 44,251 psi | 68% | 2871 fps | 95.9% |
| ADI AR 2217 | <<locked>> | 94% | 43,018 psi | 66% | 2828 fps | 96% |
| ADI AR 2225 | <<locked>> | 90% | 33,895 psi | 52% | 2657 fps | 95.6% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 40,611 psi | 63% | 2759 fps | 96% |
| Alliant Reloder-16 | <<locked>> | 80% | 46,035 psi | 71% | 2900 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 53,679 psi | 83% | 3018 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 40,234 psi | 62% | 2753 fps | 96% |
| Alliant Reloder-22 | <<locked>> | 82% | 38,827 psi | 60% | 2753 fps | 95.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 34,795 psi | 54% | 2657 fps | 99.6% |
| Alliant Reloder-25 | <<locked>> | 80% | 30,197 psi | 46% | 2556 fps | 95.5% |
| Alliant Reloder-26 | <<locked>> | 80% | 38,638 psi | 59% | 2795 fps | 99.2% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 52,939 psi | 81% | 2956 fps | 95.4% |
| Bofors RP15 | <<locked>> | 84% | 38,624 psi | 59% | 2746 fps | 95.4% |
| Bofors RP30 | <<locked>> | 92% | 42,192 psi | 65% | 2841 fps | 96% |
| Bofors RP5 | <<locked>> | 82% | 38,827 psi | 60% | 2753 fps | 95.6% |
| Bofors RP7 | <<locked>> | 80% | 50,502 psi | 78% | 2900 fps | 99.1% |
| Hodgdon H1000 | <<locked>> | 90% | 41,104 psi | 63% | 2792 fps | 96% |
| Hodgdon H414 | <<locked>> | 80% | 49,922 psi | 77% | 2943 fps | 99.4% |
| Hodgdon H4350 | <<locked>> | 80% | 52,185 psi | 80% | 2956 fps | 98.9% |
| Hodgdon H4831 | <<locked>> | 84% | 44,106 psi | 68% | 2812 fps | 95.2% |
| Hodgdon H4831 SC | <<locked>> | 86% | 46,398 psi | 71% | 2858 fps | 95.9% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 43,424 psi | 67% | 2779 fps | 100% |
| Hodgdon Retumbo | 82.3 gr | 86% | 36,230 psi | 56% | 2762 fps | 95.1% |
| Hodgdon Superformance | <<locked>> | 80% | 50,198 psi | 77% | 2966 fps | 99.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,673 psi | 43% | 1778 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 45,963 psi | 71% | 2825 fps | 98.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 51,866 psi | 80% | 2923 fps | 99.5% |
| IMR 4831 | <<locked>> | 80% | 45,818 psi | 71% | 2838 fps | 99.9% |
| IMR 4955 Enduron | <<locked>> | 84% | 45,571 psi | 70% | 2815 fps | 95.8% |
| IMR 7828 SSC | 82.2 gr | 86% | 42,670 psi | 66% | 2844 fps | 95.5% |
| IMR 8133 Enduron | <<locked>> | 98% | 40,059 psi | 62% | 2805 fps | 95.1% |
| Lovex S065 | <<locked>> | 80% | 49,516 psi | 76% | 2874 fps | 99.8% |
| Lovex S070 | <<locked>> | 80% | 47,863 psi | 74% | 2861 fps | 99.2% |
| Lovex S071 | <<locked>> | 80% | 31,125 psi | 48% | 2500 fps | 95.3% |
| Norma 204 | <<locked>> | 80% | 46,311 psi | 71% | 2864 fps | 97.5% |
| Norma 217 | <<locked>> | 94% | 35,041 psi | 54% | 2710 fps | 95.5% |
| Norma MRP | <<locked>> | 80% | 38,000 psi | 58% | 2759 fps | 96.8% |
| Norma URP | <<locked>> | 80% | 47,239 psi | 73% | 2881 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 42,627 psi | 66% | 2854 fps | 96% |
| Ramshot Hunter | <<locked>> | 80% | 46,209 psi | 71% | 2874 fps | 99.4% |
| Ramshot Magnum | <<locked>> | 84% | 35,563 psi | 55% | 2661 fps | 95.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,297 psi | 44% | 1821 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 48,573 psi | 75% | 2913 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 46,775 psi | 72% | 2930 fps | 99.9% |
| ReloadSwiss RS 76 | <<locked>> | 84% | 33,156 psi | 51% | 2667 fps | 95% |
| ReloadSwiss RS 80 | <<locked>> | 96% | 47,413 psi | 73% | 2963 fps | 96.1% |
| Rottweil R 904 | <<locked>> | 80% | 41,379 psi | 64% | 2740 fps | 95.1% |
| Rottweil R 905 | <<locked>> | 80% | 39,537 psi | 61% | 2740 fps | 95.9% |
| Rottweil R 907 | <<locked>> | 80% | 50,502 psi | 78% | 2900 fps | 99.1% |
| Shooters World Long Rifle | <<locked>> | 80% | 49,516 psi | 76% | 2874 fps | 99.8% |
| Shooters World SW4350 | <<locked>> | 80% | 47,863 psi | 74% | 2861 fps | 99.2% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 54,723 psi | 84% | 2835 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 48,515 psi | 75% | 2818 fps | 99.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 39,204 psi | 60% | 2730 fps | 95.7% |
| Somchem S355 | <<locked>> | 80% | 54,897 psi | 84% | 2956 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 45,426 psi | 70% | 2782 fps | 95.6% |
| Somchem S365 | <<locked>> | 80% | 44,367 psi | 68% | 2835 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 40,161 psi | 62% | 2720 fps | 97% |
| Vihtavuori N150 | <<locked>> | 80% | 52,591 psi | 81% | 2874 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 48,631 psi | 75% | 2874 fps | 100% |
| Vihtavuori N165 | <<locked>> | 82% | 37,304 psi | 57% | 2648 fps | 95.7% |
| Vihtavuori N550 | <<locked>> | 80% | 48,182 psi | 74% | 2877 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 38,957 psi | 60% | 2736 fps | 99.5% |
| Vihtavuori N560 | <<locked>> | 84% | 44,019 psi | 68% | 2877 fps | 95.4% |
| Vihtavuori N565 | <<locked>> | 90% | 44,628 psi | 69% | 2864 fps | 95.9% |
| Vihtavuori N568 | <<locked>> | 96% | 48,356 psi | 74% | 2976 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 48,080 psi | 74% | 2825 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 50,096 psi | 77% | 2946 fps | 99.4% |
| Winchester StaBALL HD | 78.6 gr | 80% | 31,082 psi | 48% | 2671 fps | 99.8% |
| Winchester Supreme 780 | <<locked>> | 82% | 39,552 psi | 61% | 2700 fps | 95.8% |
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 74 powders for .300 Rem. Ultra Mag. loaded with the .308 | 155gr | Berger BT Target. Hodgdon Retumbo delivers the highest muzzle velocity at 3,163 fps; across all powders the maximum-charge window runs from 1,982 fps to 3,163 fps. ADI AR 2217 gives the best case fill at 100 %, and 74 of the 74 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 155.0 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 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, Winchester StaBALL HD, IMR 7828 SSC rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 155gr | Berger BT Target 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.