Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 155gr | Norma GTX bullet and 72 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 ReloadSwiss RS 76.
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% | 55,753 psi | 86% | 2979 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 56,260 psi | 87% | 3018 fps | 100% |
| Accurate MAGPRO | <<locked>> | 92% | 58,479 psi | 90% | 3130 fps | 98.3% |
| ADI AR 2209 | <<locked>> | 90% | 57,319 psi | 88% | 3074 fps | 99.5% |
| ADI AR 2213 | <<locked>> | 92% | 55,274 psi | 85% | 3074 fps | 98.6% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 53,592 psi | 82% | 3028 fps | 98.7% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 48,298 psi | 74% | 2986 fps | 99.8% |
| Alliant Reloder-16 | <<locked>> | 86% | 56,985 psi | 88% | 3074 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 82% | 58,407 psi | 90% | 3084 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 56,739 psi | 87% | 3058 fps | 99.4% |
| Alliant Reloder-22 | <<locked>> | 92% | 55,564 psi | 86% | 3068 fps | 99.4% |
| Alliant Reloder-23 | <<locked>> | 94% | 56,956 psi | 88% | 3041 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 56,797 psi | 87% | 3104 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 90% | 57,943 psi | 89% | 3130 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 56,927 psi | 88% | 3028 fps | 96.5% |
| Bofors RP15 | <<locked>> | 96% | 58,523 psi | 90% | 3110 fps | 99.6% |
| Bofors RP30ᴾ | <<locked>> | 100% | 56,608 psi | 87% | 3100 fps | 99.2% |
| Bofors RP5 | <<locked>> | 92% | 55,564 psi | 86% | 3068 fps | 99.4% |
| Bofors RP7 | <<locked>> | 84% | 57,972 psi | 89% | 3018 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 98% | 55,143 psi | 85% | 3058 fps | 99.3% |
| Hodgdon H414 | <<locked>> | 84% | 57,827 psi | 89% | 3071 fps | 100% |
| Hodgdon H4350 | <<locked>> | 82% | 56,333 psi | 87% | 3025 fps | 99.5% |
| Hodgdon H4831 | <<locked>> | 90% | 54,911 psi | 85% | 3009 fps | 97.9% |
| Hodgdon H4831 SC | <<locked>> | 92% | 57,711 psi | 89% | 3051 fps | 98.4% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 57,508 psi | 89% | 2992 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 55,564 psi | 86% | 3173 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 82% | 54,723 psi | 84% | 3041 fps | 99.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,173 psi | 57% | 1985 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 56,246 psi | 87% | 2999 fps | 99.8% |
| IMR 4451 Enduron | <<locked>> | 82% | 55,680 psi | 86% | 2986 fps | 99.8% |
| IMR 4831 | <<locked>> | 86% | 56,623 psi | 87% | 3009 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 55,825 psi | 86% | 2995 fps | 98.2% |
| IMR 7828 SSC | <<locked>> | 94% | 57,261 psi | 88% | 3110 fps | 98.9% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 43,685 psi | 67% | 2887 fps | 96.5% |
| Lovex S065 | <<locked>> | 84% | 56,579 psi | 87% | 2986 fps | 100% |
| Lovex S070 | <<locked>> | 86% | 58,552 psi | 90% | 3035 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 56,942 psi | 88% | 2995 fps | 100% |
| Norma 204 | <<locked>> | 86% | 57,653 psi | 89% | 3058 fps | 99.4% |
| Norma 217ᴾ | <<locked>> | 100% | 43,976 psi | 68% | 2913 fps | 98.7% |
| Norma MRP | <<locked>> | 90% | 55,593 psi | 86% | 3091 fps | 99.9% |
| Norma URP | <<locked>> | 86% | 58,218 psi | 90% | 3054 fps | 100% |
| Ramshot Grand | <<locked>> | 94% | 58,349 psi | 90% | 3133 fps | 99.3% |
| Ramshot Hunter | <<locked>> | 86% | 57,334 psi | 88% | 3054 fps | 100% |
| Ramshot Magnum | <<locked>> | 96% | 57,116 psi | 88% | 3058 fps | 99.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,971 psi | 58% | 2031 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 56,405 psi | 87% | 3035 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 54,810 psi | 84% | 3058 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 57,101 psi | 88% | 3169 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 56,536 psi | 87% | 3117 fps | 98.3% |
| Rottweil R 904 | <<locked>> | 90% | 58,117 psi | 89% | 3041 fps | 98.9% |
| Rottweil R 905 | <<locked>> | 90% | 56,405 psi | 87% | 3051 fps | 99.5% |
| Rottweil R 907 | <<locked>> | 84% | 57,972 psi | 89% | 3018 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 84% | 56,579 psi | 87% | 2986 fps | 100% |
| Shooters World SW4350 | <<locked>> | 86% | 58,552 psi | 90% | 3035 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 58,711 psi | 90% | 2884 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 55,912 psi | 86% | 2936 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 55,970 psi | 86% | 3045 fps | 99.4% |
| Somchem S361 | <<locked>> | 88% | 56,260 psi | 87% | 2969 fps | 98.2% |
| Somchem S365 | <<locked>> | 86% | 55,245 psi | 85% | 2999 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 56,971 psi | 88% | 3018 fps | 99.8% |
| Vihtavuori N150 | <<locked>> | 82% | 56,637 psi | 87% | 2930 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 56,231 psi | 87% | 2989 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 56,768 psi | 87% | 2999 fps | 99.7% |
| Vihtavuori N550 | <<locked>> | 84% | 55,477 psi | 85% | 2992 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 55,216 psi | 85% | 3022 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 55,245 psi | 85% | 3084 fps | 98.2% |
| Vihtavuori N565 | <<locked>> | 96% | 55,709 psi | 86% | 3064 fps | 98.5% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 56,855 psi | 88% | 3117 fps | 97.8% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 55,985 psi | 86% | 2940 fps | 100% |
| Winchester 760 | <<locked>> | 84% | 58,030 psi | 89% | 3071 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 55,796 psi | 86% | 3123 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 57,087 psi | 88% | 3015 fps | 99.5% |
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% | 36,622 psi | 56% | 2635 fps | 97.5% |
| Accurate 4350 | <<locked>> | 80% | 48,820 psi | 75% | 2904 fps | 100% |
| Accurate MAGPRO | <<locked>> | 86% | 47,050 psi | 72% | 2933 fps | 95.7% |
| ADI AR 2209 | <<locked>> | 80% | 40,567 psi | 62% | 2769 fps | 96.1% |
| ADI AR 2213 | <<locked>> | 84% | 41,829 psi | 64% | 2818 fps | 95.1% |
| ADI AR 2217 | <<locked>> | 92% | 40,596 psi | 62% | 2776 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 90% | 34,301 psi | 53% | 2671 fps | 96% |
| Alliant Reloder-16 | <<locked>> | 80% | 46,543 psi | 72% | 2910 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 54,389 psi | 84% | 3028 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 40,625 psi | 63% | 2762 fps | 96.2% |
| Alliant Reloder-22 | <<locked>> | 82% | 39,233 psi | 60% | 2762 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 35,215 psi | 54% | 2667 fps | 99.7% |
| Alliant Reloder-25 | <<locked>> | 80% | 30,545 psi | 47% | 2562 fps | 95.8% |
| Alliant Reloder-26 | <<locked>> | 80% | 39,262 psi | 60% | 2808 fps | 99.3% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 53,447 psi | 82% | 2969 fps | 95.6% |
| Bofors RP15 | <<locked>> | 84% | 39,030 psi | 60% | 2753 fps | 95.6% |
| Bofors RP30 | <<locked>> | 90% | 39,842 psi | 61% | 2789 fps | 95.2% |
| Bofors RP5 | <<locked>> | 82% | 39,233 psi | 60% | 2762 fps | 95.8% |
| Bofors RP7 | <<locked>> | 80% | 50,937 psi | 78% | 2907 fps | 99.2% |
| Hodgdon H1000 | <<locked>> | 88% | 38,653 psi | 59% | 2736 fps | 95% |
| Hodgdon H414 | <<locked>> | 80% | 50,386 psi | 78% | 2953 fps | 99.5% |
| Hodgdon H4350 | <<locked>> | 80% | 52,779 psi | 81% | 2969 fps | 99.1% |
| Hodgdon H4831 | <<locked>> | 84% | 44,657 psi | 69% | 2825 fps | 95.4% |
| Hodgdon H4831 SC | <<locked>> | 84% | 43,859 psi | 68% | 2808 fps | 95.2% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 43,903 psi | 68% | 2785 fps | 100% |
| Hodgdon Retumbo | 83 gr | 86% | 36,579 psi | 56% | 2772 fps | 95.4% |
| Hodgdon Superformance | <<locked>> | 80% | 50,792 psi | 78% | 2976 fps | 99.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,789 psi | 43% | 1785 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 46,369 psi | 71% | 2831 fps | 98.6% |
| IMR 4451 Enduron | <<locked>> | 80% | 52,272 psi | 80% | 2930 fps | 99.6% |
| IMR 4831 | <<locked>> | 80% | 46,267 psi | 71% | 2844 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 82% | 43,018 psi | 66% | 2762 fps | 95.1% |
| IMR 7828 SSC | <<locked>> | 86% | 43,192 psi | 66% | 2858 fps | 95.7% |
| IMR 8133 Enduron | <<locked>> | 98% | 40,683 psi | 63% | 2822 fps | 95.4% |
| Lovex S065 | <<locked>> | 80% | 49,951 psi | 77% | 2881 fps | 99.9% |
| Lovex S070 | <<locked>> | 80% | 48,283 psi | 74% | 2867 fps | 99.3% |
| Lovex S071 | <<locked>> | 80% | 31,502 psi | 48% | 2510 fps | 95.5% |
| Norma 204 | <<locked>> | 80% | 46,731 psi | 72% | 2871 fps | 97.7% |
| Norma 217 | <<locked>> | 94% | 35,505 psi | 55% | 2720 fps | 95.8% |
| Norma MRP | <<locked>> | 80% | 38,551 psi | 59% | 2772 fps | 97% |
| Norma URP | <<locked>> | 80% | 47,688 psi | 73% | 2890 fps | 100% |
| Ramshot Grand | <<locked>> | 84% | 40,074 psi | 62% | 2795 fps | 95% |
| Ramshot Hunter | <<locked>> | 80% | 46,615 psi | 72% | 2881 fps | 99.5% |
| Ramshot Magnum | <<locked>> | 84% | 35,882 psi | 55% | 2667 fps | 95.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,413 psi | 44% | 1827 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 49,008 psi | 75% | 2920 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 47,210 psi | 73% | 2940 fps | 100% |
| ReloadSwiss RS 76 | 86.8 gr | 84% | 33,591 psi | 52% | 2677 fps | 95.3% |
| ReloadSwiss RS 80 | <<locked>> | 94% | 44,440 psi | 68% | 2904 fps | 95.2% |
| Rottweil R 904 | <<locked>> | 80% | 41,771 psi | 64% | 2746 fps | 95.3% |
| Rottweil R 905 | <<locked>> | 80% | 40,103 psi | 62% | 2753 fps | 96.2% |
| Rottweil R 907 | <<locked>> | 80% | 50,937 psi | 78% | 2907 fps | 99.2% |
| Shooters World Long Rifle | <<locked>> | 80% | 49,951 psi | 77% | 2881 fps | 99.9% |
| Shooters World SW4350 | <<locked>> | 80% | 48,283 psi | 74% | 2867 fps | 99.3% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 55,201 psi | 85% | 2841 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 48,936 psi | 75% | 2825 fps | 99.3% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 39,769 psi | 61% | 2746 fps | 96% |
| Somchem S361 | <<locked>> | 82% | 45,890 psi | 71% | 2792 fps | 95.9% |
| Somchem S365 | <<locked>> | 80% | 44,889 psi | 69% | 2841 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 40,698 psi | 63% | 2733 fps | 97.2% |
| Vihtavuori N150 | <<locked>> | 80% | 53,040 psi | 82% | 2881 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 49,066 psi | 76% | 2884 fps | 100% |
| Vihtavuori N165 | <<locked>> | 82% | 37,811 psi | 58% | 2657 fps | 96% |
| Vihtavuori N550 | <<locked>> | 80% | 48,588 psi | 75% | 2884 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 39,421 psi | 61% | 2746 fps | 99.6% |
| Vihtavuori N560 | <<locked>> | 84% | 44,599 psi | 69% | 2887 fps | 95.6% |
| Vihtavuori N565 | <<locked>> | 88% | 42,061 psi | 65% | 2812 fps | 95.1% |
| Vihtavuori N568 | <<locked>> | 96% | 49,066 psi | 76% | 2986 fps | 96% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 48,631 psi | 75% | 2835 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 50,575 psi | 78% | 2953 fps | 99.5% |
| Winchester StaBALL HD | 79.3 gr | 80% | 31,575 psi | 49% | 2680 fps | 99.8% |
| Winchester Supreme 780 | <<locked>> | 80% | 37,260 psi | 57% | 2651 fps | 95% |
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 72 powders for .300 Rem. Ultra Mag. loaded with the .308 | 155gr | Norma GTX. Hodgdon Retumbo delivers the highest muzzle velocity at 3,173 fps; across all powders the maximum-charge window runs from 1,985 fps to 3,173 fps. ADI AR 2217 gives the best case fill at 100 %, and 72 of the 72 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 1:13.5 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, Winchester StaBALL HD, ReloadSwiss RS 76 rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 155gr | Norma GTX 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.