Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 185gr | Berger Classic Hybrid Hunter bullet and 68 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 ReloadSwiss RS 80.
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>> | 90% | 57,479 psi | 88% | 2805 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 57,827 psi | 89% | 2828 fps | 100% |
| Accurate MAGPRO | <<locked>> | 88% | 56,333 psi | 87% | 2904 fps | 99.1% |
| ADI AR 2209 | <<locked>> | 86% | 54,984 psi | 85% | 2838 fps | 99.9% |
| ADI AR 2213 | <<locked>> | 90% | 57,087 psi | 88% | 2900 fps | 99.7% |
| ADI AR 2217 | <<locked>> | 98% | 55,622 psi | 86% | 2871 fps | 99.8% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 52,272 psi | 80% | 2904 fps | 97% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 54,201 psi | 83% | 2890 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 86% | 55,158 psi | 85% | 2835 fps | 99.9% |
| Alliant Power Pro Varmint | <<locked>> | 86% | 55,158 psi | 85% | 2835 fps | 99.9% |
| Alliant Reloder-16 | <<locked>> | 84% | 58,798 psi | 90% | 2881 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 58,291 psi | 90% | 2881 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 90% | 57,479 psi | 88% | 2897 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 90% | 55,477 psi | 85% | 2812 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 94% | 55,564 psi | 86% | 2877 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 86% | 56,101 psi | 86% | 2894 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 57,725 psi | 89% | 2959 fps | 98.1% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 57,827 psi | 89% | 2858 fps | 98.1% |
| Bofors RP15 | <<locked>> | 92% | 56,652 psi | 87% | 2884 fps | 99.9% |
| Bofors RP30 | <<locked>> | 96% | 55,288 psi | 85% | 2884 fps | 99.8% |
| Bofors RP5 | <<locked>> | 90% | 57,479 psi | 88% | 2897 fps | 100% |
| Hodgdon H1000 | <<locked>> | 96% | 57,217 psi | 88% | 2894 fps | 100% |
| Hodgdon H4831 | <<locked>> | 88% | 56,492 psi | 87% | 2841 fps | 99.3% |
| Hodgdon H4831 SC | <<locked>> | 88% | 55,274 psi | 85% | 2822 fps | 99.1% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 55,288 psi | 85% | 2756 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 58,363 psi | 90% | 3012 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,565 psi | 58% | 1834 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 57,334 psi | 88% | 2812 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 58,146 psi | 89% | 2818 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 56,898 psi | 88% | 2822 fps | 99.4% |
| IMR 7828 SSC | <<locked>> | 90% | 55,448 psi | 85% | 2884 fps | 99.6% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 49,458 psi | 76% | 2808 fps | 99.2% |
| Lovex S065 | <<locked>> | 82% | 57,537 psi | 89% | 2792 fps | 100% |
| Lovex S070 | <<locked>> | 82% | 56,101 psi | 86% | 2795 fps | 100% |
| Lovex S071 | <<locked>> | 94% | 55,463 psi | 85% | 2779 fps | 100% |
| Norma 204 | <<locked>> | 84% | 58,798 psi | 90% | 2871 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 50,285 psi | 77% | 2831 fps | 100% |
| Norma MRP | <<locked>> | 88% | 57,638 psi | 89% | 2913 fps | 100% |
| Norma URP | <<locked>> | 82% | 55,999 psi | 86% | 2812 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 56,478 psi | 87% | 2904 fps | 99.8% |
| Ramshot Hunter | <<locked>> | 84% | 58,653 psi | 90% | 2864 fps | 100% |
| Ramshot Magnum | <<locked>> | 92% | 54,969 psi | 85% | 2835 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,464 psi | 59% | 1873 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 58,131 psi | 89% | 2848 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 56,623 psi | 87% | 2874 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 94% | 55,288 psi | 85% | 2943 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 96% | 54,737 psi | 84% | 2904 fps | 99.1% |
| Rottweil R 904 | <<locked>> | 86% | 55,695 psi | 86% | 2808 fps | 99.5% |
| Rottweil R 905 | <<locked>> | 88% | 58,044 psi | 89% | 2871 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 82% | 57,537 psi | 89% | 2792 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 56,101 psi | 86% | 2795 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 56,681 psi | 87% | 2749 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 57,624 psi | 89% | 2867 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 57,334 psi | 88% | 2799 fps | 99.3% |
| Somchem S365 | <<locked>> | 84% | 57,174 psi | 88% | 2808 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 58,421 psi | 90% | 2841 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 57,479 psi | 88% | 2799 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 58,407 psi | 90% | 2825 fps | 100% |
| Vihtavuori N170 | <<locked>> | 96% | 57,537 psi | 89% | 2838 fps | 96.4% |
| Vihtavuori N550 | <<locked>> | 82% | 56,826 psi | 87% | 2805 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 57,319 psi | 88% | 2838 fps | 100% |
| Vihtavuori N560 | <<locked>> | 88% | 57,130 psi | 88% | 2917 fps | 99.5% |
| Vihtavuori N565 | <<locked>> | 94% | 57,841 psi | 89% | 2900 fps | 99.7% |
| Vihtavuori N568 | <<locked>> | 96% | 55,347 psi | 85% | 2907 fps | 98.8% |
| Vihtavuori N570 | <<locked>> | 98% | 56,550 psi | 87% | 2966 fps | 97.6% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 57,000 psi | 88% | 2746 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 90% | 54,853 psi | 84% | 2890 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 58,436 psi | 90% | 2838 fps | 100% |
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% | 40,857 psi | 63% | 2543 fps | 99.6% |
| Accurate 4350 | <<locked>> | 80% | 53,954 psi | 83% | 2776 fps | 100% |
| Accurate MAGPRO | <<locked>> | 80% | 42,221 psi | 65% | 2654 fps | 96% |
| ADI AR 2209 | <<locked>> | 80% | 44,831 psi | 69% | 2671 fps | 98.7% |
| ADI AR 2213 | <<locked>> | 80% | 40,147 psi | 62% | 2605 fps | 96.5% |
| ADI AR 2217 | <<locked>> | 86% | 36,767 psi | 57% | 2523 fps | 95.7% |
| ADI AR 2218 | <<locked>> | 98% | 48,501 psi | 75% | 2835 fps | 95.9% |
| ADI AR 2225 | <<locked>> | 82% | 29,269 psi | 45% | 2372 fps | 95.4% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 45,223 psi | 70% | 2671 fps | 98.8% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 45,223 psi | 70% | 2671 fps | 98.8% |
| Alliant Reloder-16 | <<locked>> | 80% | 51,619 psi | 79% | 2782 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 44,802 psi | 69% | 2664 fps | 98.7% |
| Alliant Reloder-22 | <<locked>> | 80% | 40,785 psi | 63% | 2615 fps | 98% |
| Alliant Reloder-23 | <<locked>> | 80% | 39,581 psi | 61% | 2566 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 34,156 psi | 53% | 2497 fps | 99% |
| Alliant Reloder-26 | <<locked>> | 80% | 44,541 psi | 69% | 2717 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 45,861 psi | 71% | 2759 fps | 95.2% |
| Baschieri & Pellagri 109 | <<locked>> | 84% | 44,773 psi | 69% | 2638 fps | 95% |
| Bofors RP15 | <<locked>> | 80% | 37,985 psi | 58% | 2552 fps | 97% |
| Bofors RP30 | <<locked>> | 84% | 36,550 psi | 56% | 2539 fps | 95.9% |
| Bofors RP5 | <<locked>> | 80% | 40,785 psi | 63% | 2615 fps | 98% |
| Hodgdon H1000 | <<locked>> | 82% | 34,954 psi | 54% | 2484 fps | 95.6% |
| Hodgdon H4831 | <<locked>> | 80% | 42,772 psi | 66% | 2608 fps | 96.7% |
| Hodgdon H4831 SC | <<locked>> | 80% | 41,989 psi | 65% | 2592 fps | 96.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 48,530 psi | 75% | 2661 fps | 100% |
| Hodgdon Retumbo | 75.3 gr | 80% | 33,301 psi | 51% | 2520 fps | 96.1% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,050 psi | 43% | 1640 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 50,531 psi | 78% | 2713 fps | 99.9% |
| IMR 4831 | <<locked>> | 80% | 50,879 psi | 78% | 2720 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 44,005 psi | 68% | 2605 fps | 97.2% |
| IMR 7828 SSC | <<locked>> | 80% | 38,972 psi | 60% | 2589 fps | 96.2% |
| IMR 8133 Enduron | <<locked>> | 90% | 35,041 psi | 54% | 2520 fps | 95.1% |
| Lovex S065 | <<locked>> | 80% | 54,143 psi | 83% | 2746 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 52,591 psi | 81% | 2743 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 35,244 psi | 54% | 2428 fps | 98.5% |
| Norma 204 | <<locked>> | 80% | 51,401 psi | 79% | 2762 fps | 99.5% |
| Norma 217 | <<locked>> | 86% | 30,618 psi | 47% | 2428 fps | 95.5% |
| Norma MRP | <<locked>> | 80% | 43,337 psi | 67% | 2684 fps | 99.4% |
| Norma URP | <<locked>> | 80% | 52,344 psi | 81% | 2759 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 38,711 psi | 60% | 2592 fps | 96.6% |
| Ramshot Hunter | <<locked>> | 80% | 51,430 psi | 79% | 2762 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 34,853 psi | 54% | 2477 fps | 97.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,776 psi | 44% | 1680 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 54,186 psi | 83% | 2795 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 52,649 psi | 81% | 2818 fps | 100% |
| ReloadSwiss RS 76 | 80.6 gr | 80% | 32,576 psi | 50% | 2493 fps | 97.1% |
| ReloadSwiss RS 80 | 89.4 gr | 88% | 40,190 psi | 62% | 2644 fps | 95.7% |
| Rottweil R 904 | <<locked>> | 80% | 45,861 psi | 71% | 2648 fps | 98.1% |
| Rottweil R 905 | <<locked>> | 80% | 44,440 psi | 68% | 2654 fps | 98.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 54,143 psi | 83% | 2746 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 52,591 psi | 81% | 2743 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 53,040 psi | 82% | 2700 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 44,106 psi | 68% | 2648 fps | 98.7% |
| Somchem S361 | <<locked>> | 80% | 46,833 psi | 72% | 2631 fps | 97.7% |
| Somchem S365 | <<locked>> | 80% | 49,966 psi | 77% | 2713 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 44,802 psi | 69% | 2631 fps | 99.3% |
| Vihtavuori N160 | <<locked>> | 80% | 53,766 psi | 83% | 2749 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 39,044 psi | 60% | 2510 fps | 98% |
| Vihtavuori N170 | <<locked>> | 94% | 53,824 psi | 83% | 2782 fps | 95.6% |
| Vihtavuori N550 | <<locked>> | 80% | 53,243 psi | 82% | 2756 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 44,121 psi | 68% | 2641 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 43,105 psi | 66% | 2674 fps | 96.9% |
| Vihtavuori N565 | <<locked>> | 82% | 38,276 psi | 59% | 2556 fps | 95.7% |
| Vihtavuori N568 | <<locked>> | 88% | 41,466 psi | 64% | 2661 fps | 95.4% |
| Vihtavuori N570 | <<locked>> | 94% | 48,834 psi | 75% | 2835 fps | 95.7% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 53,200 psi | 82% | 2700 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 37,159 psi | 57% | 2612 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 41,205 psi | 63% | 2559 fps | 98% |
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 68 powders for .300 Rem. Ultra Mag. loaded with the .308 | 185gr | Berger Classic Hybrid Hunter. Hodgdon Retumbo delivers the highest muzzle velocity at 3,012 fps; across all powders the maximum-charge window runs from 1,834 fps to 3,012 fps. ADI AR 2218 gives the best case fill at 100 %, and 68 of the 68 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 58–90 %, leaving at least 10 % headroom. The 185.0 gr projectile in 0.308" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. ADI AR 2218, 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, ReloadSwiss RS 80 rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 185gr | Berger Classic Hybrid Hunter 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.