Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 170gr | Speer Hot-Cor bullet and 71 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 Vihtavuori N560.
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% | 55,593 psi | 86% | 2874 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 55,927 psi | 86% | 2904 fps | 100% |
| Accurate MAGPRO | <<locked>> | 90% | 58,363 psi | 90% | 3025 fps | 98.9% |
| ADI AR 2209 | <<locked>> | 88% | 56,942 psi | 88% | 2963 fps | 99.8% |
| ADI AR 2213 | <<locked>> | 90% | 55,143 psi | 85% | 2966 fps | 99.1% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 57,479 psi | 88% | 2992 fps | 99.7% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 52,040 psi | 80% | 2953 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 57,246 psi | 88% | 2959 fps | 99.8% |
| Alliant Reloder-16 | <<locked>> | 84% | 56,884 psi | 88% | 2959 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 56,608 psi | 87% | 2953 fps | 99.8% |
| Alliant Reloder-22 | <<locked>> | 90% | 55,506 psi | 85% | 2966 fps | 99.8% |
| Alliant Reloder-23 | <<locked>> | 92% | 57,203 psi | 88% | 2936 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 57,130 psi | 88% | 2995 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 58,117 psi | 89% | 3022 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 55,361 psi | 85% | 3009 fps | 97% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 56,275 psi | 87% | 2927 fps | 97.3% |
| Bofors RP15 | <<locked>> | 94% | 58,450 psi | 90% | 3005 fps | 99.9% |
| Bofors RP30 | <<locked>> | 98% | 57,159 psi | 88% | 3005 fps | 99.7% |
| Bofors RP5 | <<locked>> | 90% | 55,506 psi | 85% | 2966 fps | 99.8% |
| Bofors RP7 | <<locked>> | 82% | 57,159 psi | 88% | 2904 fps | 100% |
| Hodgdon H1000 | <<locked>> | 96% | 55,085 psi | 85% | 2956 fps | 99.7% |
| Hodgdon H414 | <<locked>> | 82% | 57,493 psi | 88% | 2956 fps | 100% |
| Hodgdon H4831 | <<locked>> | 90% | 58,552 psi | 90% | 2963 fps | 99.1% |
| Hodgdon H4831 SC | <<locked>> | 90% | 57,319 psi | 88% | 2943 fps | 99% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 57,261 psi | 88% | 2881 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 55,970 psi | 86% | 3074 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 58,581 psi | 90% | 2992 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,289 psi | 57% | 1906 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 55,854 psi | 86% | 2890 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 82% | 58,668 psi | 90% | 2923 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 56,304 psi | 87% | 2894 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 55,288 psi | 85% | 2890 fps | 98.8% |
| IMR 7828 SSC | <<locked>> | 92% | 57,276 psi | 88% | 3009 fps | 99.4% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 47,514 psi | 73% | 2861 fps | 98.3% |
| Lovex S065 | <<locked>> | 82% | 56,028 psi | 86% | 2871 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 57,928 psi | 89% | 2917 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 57,000 psi | 88% | 2894 fps | 100% |
| Norma 204 | <<locked>> | 84% | 57,188 psi | 88% | 2946 fps | 99.7% |
| Norma 217ᴾ | <<locked>> | 100% | 48,080 psi | 74% | 2887 fps | 99.7% |
| Norma MRP | <<locked>> | 88% | 55,535 psi | 85% | 2982 fps | 100% |
| Norma URP | <<locked>> | 84% | 57,798 psi | 89% | 2936 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 58,610 psi | 90% | 3028 fps | 99.7% |
| Ramshot Hunter | <<locked>> | 84% | 57,014 psi | 88% | 2943 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 57,159 psi | 88% | 2956 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,290 psi | 59% | 1952 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 56,246 psi | 87% | 2923 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 54,621 psi | 84% | 2946 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 57,493 psi | 88% | 3068 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 56,782 psi | 87% | 3022 fps | 98.9% |
| Rottweil R 904 | <<locked>> | 88% | 57,754 psi | 89% | 2933 fps | 99.4% |
| Rottweil R 905 | <<locked>> | 88% | 56,144 psi | 86% | 2940 fps | 99.8% |
| Rottweil R 907 | <<locked>> | 82% | 57,159 psi | 88% | 2904 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 82% | 56,028 psi | 86% | 2871 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 57,928 psi | 89% | 2917 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 55,114 psi | 85% | 2825 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 55,738 psi | 86% | 2940 fps | 99.8% |
| Somchem S361 | <<locked>> | 86% | 55,637 psi | 86% | 2861 fps | 98.7% |
| Somchem S365 | <<locked>> | 84% | 55,332 psi | 85% | 2890 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 56,695 psi | 87% | 2910 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 55,738 psi | 86% | 2874 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 56,507 psi | 87% | 2894 fps | 99.9% |
| Vihtavuori N550 | <<locked>> | 82% | 55,056 psi | 85% | 2881 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 55,361 psi | 85% | 2910 fps | 100% |
| Vihtavuori N560 | <<locked>> | 88% | 55,085 psi | 85% | 2979 fps | 98.8% |
| Vihtavuori N565 | <<locked>> | 94% | 55,927 psi | 86% | 2966 fps | 99.1% |
| Vihtavuori N568 | <<locked>> | 98% | 57,363 psi | 88% | 3025 fps | 98.6% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 58,537 psi | 90% | 3084 fps | 97.3% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 55,419 psi | 85% | 2825 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 57,493 psi | 88% | 2956 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 56,594 psi | 87% | 3015 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 56,753 psi | 87% | 2910 fps | 99.8% |
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% | 39,450 psi | 61% | 2602 fps | 98.9% |
| Accurate 4350 | <<locked>> | 80% | 52,243 psi | 80% | 2851 fps | 100% |
| Accurate MAGPRO | <<locked>> | 82% | 43,830 psi | 67% | 2772 fps | 95.7% |
| ADI AR 2209 | <<locked>> | 80% | 43,395 psi | 67% | 2733 fps | 97.8% |
| ADI AR 2213 | <<locked>> | 80% | 38,769 psi | 60% | 2657 fps | 95.1% |
| ADI AR 2217 | <<locked>> | 88% | 37,869 psi | 58% | 2628 fps | 95.2% |
| ADI AR 2225 | <<locked>> | 86% | 32,271 psi | 50% | 2533 fps | 96.1% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 43,801 psi | 67% | 2730 fps | 97.9% |
| Alliant Reloder-16 | <<locked>> | 80% | 49,835 psi | 77% | 2854 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 43,395 psi | 67% | 2723 fps | 97.8% |
| Alliant Reloder-22 | <<locked>> | 80% | 39,305 psi | 60% | 2667 fps | 96.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 38,000 psi | 58% | 2628 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 32,880 psi | 51% | 2543 fps | 98% |
| Alliant Reloder-26 | <<locked>> | 80% | 42,670 psi | 66% | 2776 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 51,184 psi | 79% | 2940 fps | 96% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 49,617 psi | 76% | 2812 fps | 95.6% |
| Bofors RP15 | <<locked>> | 80% | 36,506 psi | 56% | 2602 fps | 95.6% |
| Bofors RP30 | <<locked>> | 86% | 37,507 psi | 58% | 2644 fps | 95.4% |
| Bofors RP5 | <<locked>> | 80% | 39,305 psi | 60% | 2667 fps | 96.8% |
| Bofors RP7 | <<locked>> | 80% | 53,795 psi | 83% | 2851 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 84% | 36,027 psi | 55% | 2585 fps | 95.1% |
| Hodgdon H414 | <<locked>> | 80% | 53,650 psi | 83% | 2900 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 41,365 psi | 64% | 2664 fps | 95.4% |
| Hodgdon H4831 SC | <<locked>> | 80% | 40,625 psi | 63% | 2648 fps | 95.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 46,920 psi | 72% | 2733 fps | 100% |
| Hodgdon Retumbo | 79.1 gr | 82% | 34,330 psi | 53% | 2625 fps | 95.6% |
| Hodgdon Superformance | <<locked>> | 80% | 54,244 psi | 83% | 2927 fps | 100% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,021 psi | 43% | 1713 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 49,153 psi | 76% | 2782 fps | 99.5% |
| IMR 4451 Enduron | <<locked>> | 80% | 55,071 psi | 85% | 2871 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 49,342 psi | 76% | 2792 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 42,786 psi | 66% | 2667 fps | 96.1% |
| IMR 7828 SSC | <<locked>> | 82% | 40,147 psi | 62% | 2700 fps | 95.7% |
| IMR 8133 Enduron | <<locked>> | 94% | 38,551 psi | 59% | 2684 fps | 95.7% |
| Lovex S065 | <<locked>> | 80% | 52,605 psi | 81% | 2818 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 50,981 psi | 78% | 2812 fps | 99.9% |
| Lovex S071 | <<locked>> | 80% | 33,852 psi | 52% | 2480 fps | 97.5% |
| Norma 204 | <<locked>> | 80% | 49,748 psi | 77% | 2828 fps | 98.9% |
| Norma 217 | <<locked>> | 90% | 33,736 psi | 52% | 2585 fps | 96.1% |
| Norma MRP | <<locked>> | 80% | 41,597 psi | 64% | 2740 fps | 98.7% |
| Norma URP | <<locked>> | 80% | 50,618 psi | 78% | 2831 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 37,289 psi | 57% | 2641 fps | 95.1% |
| Ramshot Hunter | <<locked>> | 80% | 49,748 psi | 77% | 2831 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 33,359 psi | 51% | 2520 fps | 95.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,703 psi | 44% | 1755 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 52,489 psi | 81% | 2871 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 50,821 psi | 78% | 2890 fps | 100% |
| ReloadSwiss RS 76 | 82.6 gr | 80% | 31,285 psi | 48% | 2530 fps | 95.3% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 41,553 psi | 64% | 2753 fps | 95.2% |
| Rottweil R 904 | <<locked>> | 80% | 44,425 psi | 68% | 2707 fps | 97.1% |
| Rottweil R 905 | <<locked>> | 80% | 42,815 psi | 66% | 2713 fps | 97.9% |
| Rottweil R 907 | <<locked>> | 80% | 53,795 psi | 83% | 2851 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 52,605 psi | 81% | 2818 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 50,981 psi | 78% | 2812 fps | 99.9% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 51,648 psi | 79% | 2772 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 42,482 psi | 65% | 2707 fps | 97.7% |
| Somchem S361 | <<locked>> | 80% | 45,440 psi | 70% | 2694 fps | 96.7% |
| Somchem S365 | <<locked>> | 80% | 48,240 psi | 74% | 2789 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 43,352 psi | 67% | 2690 fps | 98.6% |
| Vihtavuori N160 | <<locked>> | 80% | 52,185 psi | 80% | 2825 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 37,739 psi | 58% | 2566 fps | 96.9% |
| Vihtavuori N550 | <<locked>> | 80% | 51,648 psi | 79% | 2828 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 42,453 psi | 65% | 2703 fps | 100% |
| Vihtavuori N560 | 80.1 gr | 80% | 41,437 psi | 64% | 2726 fps | 95.6% |
| Vihtavuori N565 | <<locked>> | 84% | 39,436 psi | 61% | 2664 fps | 95.2% |
| Vihtavuori N568 | <<locked>> | 90% | 42,699 psi | 66% | 2769 fps | 95% |
| Vihtavuori N570 | <<locked>> | 96% | 50,314 psi | 77% | 2949 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 51,590 psi | 79% | 2772 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 53,838 psi | 83% | 2900 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 35,230 psi | 54% | 2664 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 39,784 psi | 61% | 2615 fps | 97% |
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 71 powders for .300 Rem. Ultra Mag. loaded with the .308 | 170gr | Speer Hot-Cor. Vihtavuori N570 delivers the highest muzzle velocity at 3,084 fps; across all powders the maximum-charge window runs from 1,906 fps to 3,084 fps. ADI AR 2217 gives the best case fill at 100 %, and 71 of the 71 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 170.0 gr projectile in 0.308" calls for a 1:14.5 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, Vihtavuori N560 rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 170gr | Speer Hot-Cor 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.