Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 170gr | Lapua Lock Base bullet and 70 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>> | 90% | 55,027 psi | 85% | 2867 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 55,463 psi | 85% | 2897 fps | 100% |
| Accurate MAGPRO | <<locked>> | 90% | 57,827 psi | 89% | 3018 fps | 98.8% |
| ADI AR 2209 | <<locked>> | 88% | 56,565 psi | 87% | 2959 fps | 99.7% |
| ADI AR 2213 | <<locked>> | 92% | 58,668 psi | 90% | 3022 fps | 99.5% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 56,971 psi | 88% | 2982 fps | 99.6% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 51,561 psi | 79% | 2946 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 56,420 psi | 87% | 2953 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 56,057 psi | 86% | 2946 fps | 99.7% |
| Alliant Reloder-22 | <<locked>> | 90% | 55,158 psi | 85% | 2959 fps | 99.7% |
| Alliant Reloder-23 | <<locked>> | 92% | 56,550 psi | 87% | 2927 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 56,521 psi | 87% | 2989 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 57,464 psi | 88% | 3012 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 54,650 psi | 84% | 2999 fps | 96.8% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 55,883 psi | 86% | 2917 fps | 97.1% |
| Bofors RP15 | <<locked>> | 94% | 58,088 psi | 89% | 3002 fps | 99.9% |
| Bofors RP30 | <<locked>> | 98% | 56,391 psi | 87% | 2995 fps | 99.6% |
| Bofors RP5 | <<locked>> | 90% | 55,158 psi | 85% | 2959 fps | 99.7% |
| Bofors RP7 | <<locked>> | 82% | 56,942 psi | 88% | 2897 fps | 100% |
| Hodgdon H1000 | <<locked>> | 98% | 58,798 psi | 90% | 3012 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 82% | 56,826 psi | 87% | 2946 fps | 100% |
| Hodgdon H4831 | <<locked>> | 90% | 57,972 psi | 89% | 2953 fps | 99% |
| Hodgdon H4831 SC | <<locked>> | 90% | 56,971 psi | 88% | 2940 fps | 98.9% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 56,623 psi | 87% | 2874 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 55,376 psi | 85% | 3064 fps | 100% |
| Hodgdon Superformance | <<locked>> | 82% | 58,015 psi | 89% | 2982 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,347 psi | 57% | 1906 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 55,477 psi | 85% | 2884 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 82% | 58,291 psi | 90% | 2920 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 55,825 psi | 86% | 2887 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 58,566 psi | 90% | 2936 fps | 99.2% |
| IMR 7828 SSC | <<locked>> | 92% | 56,681 psi | 87% | 2999 fps | 99.3% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 46,949 psi | 72% | 2851 fps | 98.2% |
| Lovex S065 | <<locked>> | 82% | 55,666 psi | 86% | 2864 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 57,537 psi | 89% | 2913 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 56,594 psi | 87% | 2890 fps | 100% |
| Norma 204 | <<locked>> | 84% | 56,608 psi | 87% | 2936 fps | 99.7% |
| Norma 217ᴾ | <<locked>> | 100% | 47,529 psi | 73% | 2877 fps | 99.7% |
| Norma MRP | <<locked>> | 88% | 55,100 psi | 85% | 2976 fps | 100% |
| Norma URP | <<locked>> | 84% | 57,363 psi | 88% | 2930 fps | 100% |
| Ramshot Grand | <<locked>> | 92% | 57,972 psi | 89% | 3022 fps | 99.7% |
| Ramshot Hunter | <<locked>> | 84% | 56,449 psi | 87% | 2936 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 56,565 psi | 87% | 2949 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,189 psi | 59% | 1949 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 55,651 psi | 86% | 2913 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 58,233 psi | 90% | 2995 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 56,695 psi | 87% | 3058 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 56,231 psi | 87% | 3015 fps | 98.8% |
| Rottweil R 904 | <<locked>> | 88% | 57,188 psi | 88% | 2923 fps | 99.3% |
| Rottweil R 905 | <<locked>> | 88% | 55,724 psi | 86% | 2936 fps | 99.7% |
| Rottweil R 907 | <<locked>> | 82% | 56,942 psi | 88% | 2897 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 82% | 55,666 psi | 86% | 2864 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 57,537 psi | 89% | 2913 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 58,450 psi | 90% | 2871 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 55,317 psi | 85% | 2930 fps | 99.7% |
| Somchem S361 | <<locked>> | 86% | 55,332 psi | 85% | 2858 fps | 98.6% |
| Somchem S365 | <<locked>> | 86% | 58,740 psi | 90% | 2933 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 56,144 psi | 86% | 2904 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 55,317 psi | 85% | 2871 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 55,999 psi | 86% | 2887 fps | 99.9% |
| Vihtavuori N550 | <<locked>> | 84% | 58,276 psi | 90% | 2927 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 58,537 psi | 90% | 2956 fps | 100% |
| Vihtavuori N560 | <<locked>> | 90% | 58,711 psi | 90% | 3035 fps | 99.3% |
| Vihtavuori N565 | <<locked>> | 94% | 55,390 psi | 85% | 2956 fps | 99% |
| Vihtavuori N568 | <<locked>> | 98% | 56,623 psi | 87% | 3015 fps | 98.4% |
| Vihtavuori N570ᴾ | <<locked>> | 100% | 57,769 psi | 89% | 3074 fps | 97.1% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 54,868 psi | 84% | 2818 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 57,029 psi | 88% | 2953 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 56,014 psi | 86% | 3009 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 56,188 psi | 86% | 2900 fps | 99.7% |
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% | 39,044 psi | 60% | 2595 fps | 98.8% |
| Accurate 4350 | <<locked>> | 80% | 51,750 psi | 80% | 2844 fps | 100% |
| Accurate MAGPRO | <<locked>> | 82% | 43,308 psi | 67% | 2766 fps | 95.5% |
| ADI AR 2209 | <<locked>> | 80% | 43,033 psi | 66% | 2723 fps | 97.7% |
| ADI AR 2213 | <<locked>> | 82% | 41,350 psi | 64% | 2717 fps | 96.1% |
| ADI AR 2217 | <<locked>> | 88% | 37,565 psi | 58% | 2621 fps | 95% |
| ADI AR 2225 | <<locked>> | 86% | 31,995 psi | 49% | 2526 fps | 95.9% |
| Alliant Reloder-16 | <<locked>> | 80% | 49,371 psi | 76% | 2848 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 43,004 psi | 66% | 2717 fps | 97.7% |
| Alliant Reloder-22 | <<locked>> | 80% | 38,943 psi | 60% | 2661 fps | 96.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 37,565 psi | 58% | 2618 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 32,576 psi | 50% | 2536 fps | 97.8% |
| Alliant Reloder-26 | <<locked>> | 80% | 42,250 psi | 65% | 2769 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 50,749 psi | 78% | 2933 fps | 95.8% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 49,240 psi | 76% | 2802 fps | 95.4% |
| Bofors RP15 | <<locked>> | 80% | 36,274 psi | 56% | 2598 fps | 95.5% |
| Bofors RP30 | <<locked>> | 86% | 37,115 psi | 57% | 2638 fps | 95.2% |
| Bofors RP5 | <<locked>> | 80% | 38,943 psi | 60% | 2661 fps | 96.7% |
| Bofors RP7 | <<locked>> | 80% | 53,388 psi | 82% | 2844 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 86% | 38,319 psi | 59% | 2641 fps | 96.1% |
| Hodgdon H414 | <<locked>> | 80% | 53,229 psi | 82% | 2894 fps | 99.9% |
| Hodgdon H4831 | <<locked>> | 80% | 41,002 psi | 63% | 2657 fps | 95.2% |
| Hodgdon H4831 SC | <<locked>> | 80% | 40,263 psi | 62% | 2641 fps | 95% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 46,499 psi | 72% | 2726 fps | 100% |
| Hodgdon Retumbo | 78.5 gr | 82% | 33,997 psi | 52% | 2615 fps | 95.3% |
| Hodgdon Superformance | <<locked>> | 80% | 53,853 psi | 83% | 2920 fps | 99.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,007 psi | 43% | 1713 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 48,762 psi | 75% | 2779 fps | 99.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 54,708 psi | 84% | 2867 fps | 100% |
| IMR 4831 | <<locked>> | 80% | 48,907 psi | 75% | 2785 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 42,424 psi | 65% | 2661 fps | 95.9% |
| IMR 7828 SSC | <<locked>> | 82% | 39,784 psi | 61% | 2690 fps | 95.6% |
| IMR 8133 Enduron | <<locked>> | 94% | 38,043 psi | 59% | 2671 fps | 95.4% |
| Lovex S065 | <<locked>> | 80% | 52,199 psi | 80% | 2815 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 50,792 psi | 78% | 2812 fps | 99.9% |
| Lovex S071 | <<locked>> | 80% | 33,605 psi | 52% | 2474 fps | 97.3% |
| Norma 204 | <<locked>> | 80% | 49,356 psi | 76% | 2822 fps | 98.8% |
| Norma 217 | <<locked>> | 90% | 33,272 psi | 51% | 2575 fps | 95.8% |
| Norma MRP | <<locked>> | 80% | 41,162 psi | 63% | 2730 fps | 98.5% |
| Norma URP | <<locked>> | 80% | 50,357 psi | 78% | 2828 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 39,697 psi | 61% | 2700 fps | 96% |
| Ramshot Hunter | <<locked>> | 80% | 49,356 psi | 76% | 2828 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 80% | 33,054 psi | 51% | 2513 fps | 95.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,674 psi | 44% | 1752 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 51,880 psi | 80% | 2861 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 50,357 psi | 78% | 2884 fps | 100% |
| ReloadSwiss RS 76 | 82 gr | 80% | 31,009 psi | 48% | 2523 fps | 95.1% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 41,017 psi | 63% | 2743 fps | 95% |
| Rottweil R 904 | <<locked>> | 80% | 44,048 psi | 68% | 2700 fps | 96.9% |
| Rottweil R 905 | <<locked>> | 80% | 42,453 psi | 65% | 2703 fps | 97.7% |
| Rottweil R 907 | <<locked>> | 80% | 53,388 psi | 82% | 2844 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 52,199 psi | 80% | 2815 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 50,792 psi | 78% | 2812 fps | 99.9% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 51,300 psi | 79% | 2766 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 42,105 psi | 65% | 2700 fps | 97.6% |
| Somchem S361 | <<locked>> | 80% | 45,150 psi | 69% | 2687 fps | 96.5% |
| Somchem S365 | <<locked>> | 80% | 47,805 psi | 74% | 2782 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 42,989 psi | 66% | 2684 fps | 98.5% |
| Vihtavuori N160 | <<locked>> | 80% | 51,750 psi | 80% | 2818 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 37,420 psi | 58% | 2559 fps | 96.8% |
| Vihtavuori N550 | <<locked>> | 80% | 51,242 psi | 79% | 2825 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 42,018 psi | 65% | 2697 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 41,060 psi | 63% | 2720 fps | 95.4% |
| Vihtavuori N565 | <<locked>> | 84% | 39,059 psi | 60% | 2654 fps | 95% |
| Vihtavuori N568 | <<locked>> | 92% | 45,426 psi | 70% | 2825 fps | 95.9% |
| Vihtavuori N570 | <<locked>> | 96% | 49,748 psi | 77% | 2940 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 51,256 psi | 79% | 2769 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 53,417 psi | 82% | 2897 fps | 99.9% |
| Winchester StaBALL HD | 78.7 gr | 80% | 34,737 psi | 53% | 2654 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 39,436 psi | 61% | 2608 fps | 96.8% |
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 76 powders for .300 Rem. Ultra Mag. loaded with the .308 | 170gr | Lapua Lock Base. Vihtavuori N570 delivers the highest muzzle velocity at 3,074 fps; across all powders the maximum-charge window runs from 1,906 fps to 3,074 fps. ADI AR 2217 gives the best case fill at 100 %, and 76 of the 76 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 1:13.5 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2218, ADI AR 2225 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 | 170gr | Lapua Lock Base they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Alliant Reloder-50, IMR 7977 Enduron, Lovex D100 burn incompletely and react more sensitively to barrel length and temperature. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.