Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 172gr | Speer Impact 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 Accurate MAGPRO.
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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You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 92% | 57,667 psi | 89% | 2890 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 58,305 psi | 90% | 2923 fps | 100% |
| Accurate MAGPRO | <<locked>> | 90% | 56,492 psi | 87% | 2986 fps | 98.6% |
| ADI AR 2209 | <<locked>> | 88% | 55,274 psi | 85% | 2923 fps | 99.6% |
| ADI AR 2213 | <<locked>> | 92% | 57,276 psi | 88% | 2986 fps | 99.3% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 55,579 psi | 86% | 2949 fps | 99.5% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 50,096 psi | 77% | 2910 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 55,637 psi | 86% | 2923 fps | 99.7% |
| Alliant Reloder-16 | <<locked>> | 84% | 55,288 psi | 85% | 2923 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 58,610 psi | 90% | 2966 fps | 99.9% |
| Alliant Reloder-22 | <<locked>> | 92% | 57,580 psi | 89% | 2982 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 92% | 55,245 psi | 85% | 2897 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 55,114 psi | 85% | 2959 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 55,941 psi | 86% | 2979 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 53,084 psi | 82% | 2963 fps | 96.4% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 58,450 psi | 90% | 2943 fps | 97.6% |
| Bofors RP15 | <<locked>> | 94% | 56,739 psi | 87% | 2969 fps | 99.8% |
| Bofors RP30 | <<locked>> | 98% | 55,085 psi | 85% | 2963 fps | 99.5% |
| Bofors RP5 | <<locked>> | 92% | 57,580 psi | 89% | 2982 fps | 99.9% |
| Bofors RP7 | <<locked>> | 82% | 55,956 psi | 86% | 2867 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 98% | 57,363 psi | 88% | 2976 fps | 99.8% |
| Hodgdon H414 | <<locked>> | 82% | 55,854 psi | 86% | 2920 fps | 100% |
| Hodgdon H4350 | <<locked>> | 82% | 58,030 psi | 89% | 2930 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 90% | 56,855 psi | 88% | 2923 fps | 98.8% |
| Hodgdon H4831 SC | <<locked>> | 90% | 55,637 psi | 86% | 2904 fps | 98.7% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 55,579 psi | 86% | 2844 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 58,059 psi | 89% | 3094 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 56,797 psi | 87% | 2953 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,318 psi | 57% | 1886 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 58,044 psi | 89% | 2904 fps | 100% |
| IMR 4451 Enduron | <<locked>> | 82% | 57,305 psi | 88% | 2887 fps | 100% |
| IMR 4831 | <<locked>> | 86% | 58,450 psi | 90% | 2910 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 57,464 psi | 88% | 2907 fps | 99% |
| IMR 7828 SSC | <<locked>> | 92% | 55,448 psi | 85% | 2966 fps | 99.2% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 45,571 psi | 70% | 2818 fps | 97.9% |
| Lovex S065 | <<locked>> | 84% | 58,320 psi | 90% | 2887 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 56,594 psi | 87% | 2884 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 55,376 psi | 85% | 2858 fps | 100% |
| Norma 204 | <<locked>> | 84% | 55,550 psi | 85% | 2907 fps | 99.6% |
| Norma 217ᴾ | <<locked>> | 100% | 46,035 psi | 71% | 2844 fps | 99.5% |
| Norma MRP | <<locked>> | 90% | 57,812 psi | 89% | 3002 fps | 100% |
| Norma URP | <<locked>> | 84% | 56,289 psi | 87% | 2900 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 56,463 psi | 87% | 2986 fps | 99.5% |
| Ramshot Hunter | <<locked>> | 84% | 55,361 psi | 85% | 2907 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 55,071 psi | 85% | 2917 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,174 psi | 59% | 1929 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 58,465 psi | 90% | 2940 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 57,116 psi | 88% | 2969 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 55,056 psi | 85% | 3022 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 54,534 psi | 84% | 2979 fps | 98.6% |
| Rottweil R 904 | <<locked>> | 88% | 56,159 psi | 86% | 2894 fps | 99.2% |
| Rottweil R 905 | <<locked>> | 90% | 58,334 psi | 90% | 2959 fps | 99.9% |
| Rottweil R 907 | <<locked>> | 82% | 55,956 psi | 86% | 2867 fps | 99.9% |
| Shooters World Long Rifle | <<locked>> | 84% | 58,320 psi | 90% | 2887 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 56,594 psi | 87% | 2884 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 57,363 psi | 88% | 2841 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 57,899 psi | 89% | 2953 fps | 99.9% |
| Somchem S361 | <<locked>> | 88% | 57,957 psi | 89% | 2881 fps | 99% |
| Somchem S365 | <<locked>> | 86% | 57,435 psi | 88% | 2904 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 58,740 psi | 90% | 2927 fps | 100% |
| Vihtavuori N150 | <<locked>> | 82% | 58,363 psi | 90% | 2828 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 58,102 psi | 89% | 2894 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 58,740 psi | 90% | 2910 fps | 100% |
| Vihtavuori N550 | <<locked>> | 84% | 57,392 psi | 88% | 2897 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 57,348 psi | 88% | 2927 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 57,319 psi | 88% | 2999 fps | 99.1% |
| Vihtavuori N565 | <<locked>> | 96% | 57,769 psi | 89% | 2979 fps | 99.3% |
| Vihtavuori N568 | <<locked>> | 98% | 55,042 psi | 85% | 2979 fps | 98.2% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 56,159 psi | 86% | 3038 fps | 96.7% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 57,812 psi | 89% | 2841 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 56,043 psi | 86% | 2923 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 58,552 psi | 90% | 3031 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 54,897 psi | 84% | 2867 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% | 38,261 psi | 59% | 2566 fps | 98.7% |
| Accurate 4350 | <<locked>> | 80% | 50,821 psi | 78% | 2815 fps | 100% |
| Accurate MAGPRO | 80.9 gr | 82% | 42,293 psi | 65% | 2730 fps | 95.1% |
| ADI AR 2209 | <<locked>> | 80% | 42,206 psi | 65% | 2694 fps | 97.5% |
| ADI AR 2213 | <<locked>> | 82% | 40,350 psi | 62% | 2684 fps | 95.7% |
| ADI AR 2217 | <<locked>> | 90% | 39,305 psi | 60% | 2651 fps | 95.7% |
| ADI AR 2225 | <<locked>> | 86% | 31,256 psi | 48% | 2493 fps | 95.5% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 42,627 psi | 66% | 2694 fps | 97.6% |
| Alliant Reloder-16 | <<locked>> | 80% | 48,356 psi | 74% | 2818 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 42,235 psi | 65% | 2687 fps | 97.5% |
| Alliant Reloder-22 | <<locked>> | 80% | 38,159 psi | 59% | 2631 fps | 96.4% |
| Alliant Reloder-23 | <<locked>> | 80% | 36,695 psi | 56% | 2592 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 31,879 psi | 49% | 2507 fps | 97.5% |
| Alliant Reloder-26 | <<locked>> | 80% | 41,104 psi | 63% | 2736 fps | 99.9% |
| Alliant Reloder-33 | <<locked>> | 98% | 49,168 psi | 76% | 2894 fps | 95.3% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 48,312 psi | 74% | 2769 fps | 95.1% |
| Bofors RP15 | <<locked>> | 80% | 35,491 psi | 55% | 2566 fps | 95.2% |
| Bofors RP30 | <<locked>> | 88% | 38,870 psi | 60% | 2667 fps | 95.9% |
| Bofors RP5 | <<locked>> | 80% | 38,159 psi | 59% | 2631 fps | 96.4% |
| Bofors RP7 | <<locked>> | 80% | 52,547 psi | 81% | 2815 fps | 99.7% |
| Hodgdon H1000 | <<locked>> | 86% | 37,492 psi | 58% | 2608 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 80% | 52,214 psi | 80% | 2861 fps | 99.9% |
| Hodgdon H4350 | <<locked>> | 80% | 54,476 psi | 84% | 2877 fps | 99.6% |
| Hodgdon H4831 | <<locked>> | 82% | 43,062 psi | 66% | 2687 fps | 95.9% |
| Hodgdon H4831 SC | <<locked>> | 82% | 42,264 psi | 65% | 2671 fps | 95.6% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 45,542 psi | 70% | 2697 fps | 100% |
| Hodgdon Retumbo | 78.4 gr | 84% | 35,636 psi | 55% | 2651 fps | 96.2% |
| Hodgdon Superformance | <<locked>> | 80% | 52,576 psi | 81% | 2887 fps | 99.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,891 psi | 43% | 1693 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 47,950 psi | 74% | 2746 fps | 99.3% |
| IMR 4451 Enduron | <<locked>> | 80% | 53,867 psi | 83% | 2838 fps | 99.9% |
| IMR 4831 | <<locked>> | 80% | 48,051 psi | 74% | 2759 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 41,727 psi | 64% | 2631 fps | 95.7% |
| IMR 7828 SSC | <<locked>> | 82% | 38,914 psi | 60% | 2657 fps | 95.2% |
| IMR 8133 Enduron | <<locked>> | 94% | 37,072 psi | 57% | 2641 fps | 95% |
| Lovex S065 | <<locked>> | 80% | 51,343 psi | 79% | 2785 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 49,937 psi | 77% | 2782 fps | 99.8% |
| Lovex S071 | <<locked>> | 80% | 32,779 psi | 50% | 2441 fps | 97% |
| Norma 204 | <<locked>> | 80% | 48,443 psi | 75% | 2789 fps | 98.7% |
| Norma 217 | <<locked>> | 90% | 32,416 psi | 50% | 2543 fps | 95.4% |
| Norma MRP | <<locked>> | 80% | 40,248 psi | 62% | 2700 fps | 98.3% |
| Norma URP | <<locked>> | 80% | 49,472 psi | 76% | 2799 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 38,827 psi | 60% | 2667 fps | 95.7% |
| Ramshot Hunter | <<locked>> | 80% | 48,399 psi | 74% | 2799 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 80% | 32,285 psi | 50% | 2484 fps | 95% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,587 psi | 44% | 1732 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 50,850 psi | 78% | 2831 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 49,182 psi | 76% | 2854 fps | 100% |
| ReloadSwiss RS 76 | 81.9 gr | 82% | 32,547 psi | 50% | 2556 fps | 96% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 42,960 psi | 66% | 2772 fps | 95.7% |
| Rottweil R 904 | <<locked>> | 80% | 43,265 psi | 67% | 2671 fps | 96.7% |
| Rottweil R 905 | <<locked>> | 80% | 41,597 psi | 64% | 2677 fps | 97.5% |
| Rottweil R 907 | <<locked>> | 80% | 52,547 psi | 81% | 2815 fps | 99.7% |
| Shooters World Long Rifle | <<locked>> | 80% | 51,343 psi | 79% | 2785 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 49,937 psi | 77% | 2782 fps | 99.8% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 50,343 psi | 77% | 2736 fps | 99.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 41,263 psi | 64% | 2671 fps | 97.4% |
| Somchem S361 | <<locked>> | 80% | 44,237 psi | 68% | 2657 fps | 96.3% |
| Somchem S365 | <<locked>> | 80% | 46,818 psi | 72% | 2753 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 42,221 psi | 65% | 2657 fps | 98.4% |
| Vihtavuori N150 | <<locked>> | 80% | 54,781 psi | 84% | 2779 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 50,894 psi | 78% | 2792 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 36,695 psi | 56% | 2530 fps | 96.5% |
| Vihtavuori N550 | <<locked>> | 80% | 50,299 psi | 77% | 2795 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 41,104 psi | 63% | 2667 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 40,190 psi | 62% | 2690 fps | 95.1% |
| Vihtavuori N565 | <<locked>> | 86% | 40,857 psi | 63% | 2684 fps | 95.7% |
| Vihtavuori N568 | <<locked>> | 92% | 44,251 psi | 68% | 2789 fps | 95.5% |
| Vihtavuori N570 | <<locked>> | 98% | 51,996 psi | 80% | 2966 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 50,227 psi | 77% | 2743 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 52,402 psi | 81% | 2864 fps | 99.9% |
| Winchester StaBALL HD | <<locked>> | 80% | 33,649 psi | 52% | 2625 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 38,740 psi | 60% | 2582 fps | 96.6% |
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 | 172gr | Speer Impact. Hodgdon Retumbo delivers the highest muzzle velocity at 3,094 fps; across all powders the maximum-charge window runs from 1,886 fps to 3,094 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 172.0 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, 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, Accurate MAGPRO rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 172gr | Speer Impact 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.