Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 165gr | Remington PSP Core-Lokt 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, 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% | 55,912 psi | 86% | 2913 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 56,333 psi | 87% | 2946 fps | 100% |
| Accurate High Country | <<locked>> | 88% | 57,711 psi | 89% | 3064 fps | 99.4% |
| Accurate MAGPRO | <<locked>> | 88% | 54,781 psi | 84% | 3005 fps | 98.2% |
| ADI AR 2209 | <<locked>> | 88% | 57,334 psi | 88% | 3005 fps | 99.8% |
| ADI AR 2213 | <<locked>> | 90% | 55,593 psi | 86% | 3009 fps | 99.1% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 58,044 psi | 89% | 3031 fps | 99.7% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 52,562 psi | 81% | 2992 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 57,624 psi | 89% | 3002 fps | 99.8% |
| Alliant Reloder-16 | <<locked>> | 84% | 57,348 psi | 88% | 3002 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 56,971 psi | 88% | 2992 fps | 99.7% |
| Alliant Reloder-22 | <<locked>> | 90% | 55,999 psi | 86% | 3005 fps | 99.7% |
| Alliant Reloder-23 | <<locked>> | 92% | 57,522 psi | 89% | 2972 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 96% | 57,711 psi | 89% | 3038 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 88% | 58,755 psi | 90% | 3061 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 56,072 psi | 86% | 3051 fps | 97% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 56,623 psi | 87% | 2963 fps | 97.2% |
| Bofors RP15 | <<locked>> | 92% | 55,201 psi | 85% | 2992 fps | 99.6% |
| Bofors RP30 | <<locked>> | 98% | 57,609 psi | 89% | 3045 fps | 99.6% |
| Bofors RP5 | <<locked>> | 90% | 55,999 psi | 86% | 3005 fps | 99.7% |
| Bofors RP7 | <<locked>> | 82% | 57,624 psi | 89% | 2943 fps | 100% |
| Hodgdon H1000 | <<locked>> | 96% | 55,753 psi | 86% | 2999 fps | 99.7% |
| Hodgdon H414 | <<locked>> | 82% | 57,798 psi | 89% | 2995 fps | 100% |
| Hodgdon H4831 | <<locked>> | 88% | 55,042 psi | 85% | 2943 fps | 98.5% |
| Hodgdon H4831 SC | <<locked>> | 90% | 57,798 psi | 89% | 2986 fps | 98.9% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 57,421 psi | 88% | 2920 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 56,695 psi | 87% | 3120 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,289 psi | 57% | 1942 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 56,159 psi | 86% | 2930 fps | 99.9% |
| IMR 4831 | <<locked>> | 84% | 56,652 psi | 87% | 2933 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 55,637 psi | 86% | 2930 fps | 98.8% |
| IMR 7828 SSC | <<locked>> | 92% | 57,740 psi | 89% | 3048 fps | 99.4% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 47,921 psi | 74% | 2900 fps | 98.3% |
| Lovex S065 | <<locked>> | 82% | 56,304 psi | 87% | 2913 fps | 100% |
| Lovex S070 | <<locked>> | 84% | 58,291 psi | 90% | 2959 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 57,493 psi | 88% | 2933 fps | 100% |
| Norma 204 | <<locked>> | 84% | 57,421 psi | 88% | 2982 fps | 99.7% |
| Norma 217ᴾ | <<locked>> | 100% | 48,733 psi | 75% | 2927 fps | 99.7% |
| Norma MRP | <<locked>> | 88% | 55,999 psi | 86% | 3022 fps | 100% |
| Norma URP | <<locked>> | 84% | 58,175 psi | 90% | 2976 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 54,694 psi | 84% | 3005 fps | 99.3% |
| Ramshot Hunter | <<locked>> | 84% | 57,261 psi | 88% | 2982 fps | 100% |
| Ramshot Magnum | <<locked>> | 94% | 57,754 psi | 89% | 2999 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,276 psi | 59% | 1988 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 56,507 psi | 87% | 2963 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 55,056 psi | 85% | 2989 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 57,972 psi | 89% | 3107 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 98% | 57,624 psi | 89% | 3064 fps | 99% |
| Rottweil R 904 | <<locked>> | 88% | 57,972 psi | 89% | 2972 fps | 99.3% |
| Rottweil R 905 | <<locked>> | 88% | 56,565 psi | 87% | 2982 fps | 99.8% |
| Rottweil R 907 | <<locked>> | 82% | 57,624 psi | 89% | 2943 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 82% | 56,304 psi | 87% | 2913 fps | 100% |
| Shooters World SW4350 | <<locked>> | 84% | 58,291 psi | 90% | 2959 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 55,332 psi | 85% | 2861 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 56,144 psi | 86% | 2976 fps | 99.7% |
| Somchem S361 | <<locked>> | 86% | 56,028 psi | 86% | 2900 fps | 98.7% |
| Somchem S365 | <<locked>> | 84% | 55,695 psi | 86% | 2927 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 57,029 psi | 88% | 2953 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 56,159 psi | 86% | 2917 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 56,913 psi | 88% | 2933 fps | 99.9% |
| Vihtavuori N550 | <<locked>> | 82% | 55,376 psi | 85% | 2920 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 55,840 psi | 86% | 2953 fps | 100% |
| Vihtavuori N560 | <<locked>> | 88% | 55,521 psi | 85% | 3018 fps | 98.8% |
| Vihtavuori N565 | <<locked>> | 94% | 56,391 psi | 87% | 3002 fps | 99.1% |
| Vihtavuori N568 | <<locked>> | 98% | 57,856 psi | 89% | 3068 fps | 98.6% |
| Vihtavuori N570 | <<locked>> | 98% | 54,868 psi | 84% | 3058 fps | 96.3% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 55,753 psi | 86% | 2864 fps | 100% |
| Winchester 760 | <<locked>> | 82% | 57,986 psi | 89% | 3002 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 92% | 57,348 psi | 88% | 3058 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 57,174 psi | 88% | 2949 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% | 39,668 psi | 61% | 2638 fps | 98.9% |
| Accurate 4350 | <<locked>> | 80% | 52,518 psi | 81% | 2890 fps | 100% |
| Accurate High Country | <<locked>> | 80% | 43,337 psi | 67% | 2808 fps | 96.7% |
| Accurate MAGPRO | <<locked>> | 82% | 44,193 psi | 68% | 2812 fps | 95.6% |
| ADI AR 2209 | <<locked>> | 80% | 43,642 psi | 67% | 2769 fps | 97.7% |
| ADI AR 2213 | <<locked>> | 80% | 39,117 psi | 60% | 2697 fps | 95% |
| ADI AR 2217 | <<locked>> | 88% | 38,189 psi | 59% | 2664 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 86% | 32,547 psi | 50% | 2566 fps | 96% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 44,034 psi | 68% | 2769 fps | 97.8% |
| Alliant Reloder-16 | <<locked>> | 80% | 49,980 psi | 77% | 2894 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 43,613 psi | 67% | 2762 fps | 97.8% |
| Alliant Reloder-22 | <<locked>> | 80% | 39,682 psi | 61% | 2707 fps | 96.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 38,305 psi | 59% | 2664 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 33,098 psi | 51% | 2575 fps | 97.9% |
| Alliant Reloder-26 | <<locked>> | 80% | 43,134 psi | 66% | 2812 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 98% | 51,953 psi | 80% | 2982 fps | 96% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 49,908 psi | 77% | 2848 fps | 95.5% |
| Bofors RP15 | <<locked>> | 80% | 36,767 psi | 57% | 2638 fps | 95.5% |
| Bofors RP30 | <<locked>> | 86% | 37,884 psi | 58% | 2680 fps | 95.3% |
| Bofors RP5 | <<locked>> | 80% | 39,682 psi | 61% | 2707 fps | 96.7% |
| Bofors RP7 | <<locked>> | 80% | 53,925 psi | 83% | 2887 fps | 99.8% |
| Hodgdon H1000 | <<locked>> | 84% | 36,260 psi | 56% | 2621 fps | 95% |
| Hodgdon H414 | <<locked>> | 80% | 54,041 psi | 83% | 2943 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 41,698 psi | 64% | 2703 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 80% | 40,959 psi | 63% | 2687 fps | 95% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 47,108 psi | 73% | 2769 fps | 100% |
| Hodgdon Retumbo | 81.1 gr | 82% | 34,606 psi | 53% | 2661 fps | 95.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,963 psi | 43% | 1742 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 49,400 psi | 76% | 2822 fps | 99.5% |
| IMR 4831 | <<locked>> | 80% | 49,632 psi | 76% | 2831 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 43,004 psi | 66% | 2703 fps | 95.9% |
| IMR 7828 SSC | <<locked>> | 82% | 40,437 psi | 62% | 2733 fps | 95.6% |
| IMR 8133 Enduron | <<locked>> | 94% | 38,928 psi | 60% | 2717 fps | 95.6% |
| Lovex S065 | <<locked>> | 80% | 52,881 psi | 81% | 2861 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 51,256 psi | 79% | 2854 fps | 99.9% |
| Lovex S071 | <<locked>> | 80% | 34,040 psi | 52% | 2510 fps | 97.3% |
| Norma 204 | <<locked>> | 80% | 50,111 psi | 77% | 2867 fps | 98.9% |
| Norma 217 | <<locked>> | 90% | 34,026 psi | 52% | 2618 fps | 96% |
| Norma MRP | <<locked>> | 80% | 41,887 psi | 64% | 2776 fps | 98.6% |
| Norma URP | <<locked>> | 80% | 50,923 psi | 78% | 2871 fps | 100% |
| Ramshot Grand | <<locked>> | 82% | 40,451 psi | 62% | 2743 fps | 96.1% |
| Ramshot Hunter | <<locked>> | 80% | 50,111 psi | 77% | 2871 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 33,736 psi | 52% | 2556 fps | 95.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,631 psi | 44% | 1785 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 52,823 psi | 81% | 2910 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 51,082 psi | 79% | 2927 fps | 100% |
| ReloadSwiss RS 76 | 84.7 gr | 80% | 31,589 psi | 49% | 2562 fps | 95.2% |
| ReloadSwiss RS 80 | <<locked>> | 90% | 41,945 psi | 65% | 2785 fps | 95.2% |
| Rottweil R 904 | <<locked>> | 80% | 44,686 psi | 69% | 2746 fps | 97% |
| Rottweil R 905 | <<locked>> | 80% | 43,076 psi | 66% | 2749 fps | 97.8% |
| Rottweil R 907 | <<locked>> | 80% | 53,925 psi | 83% | 2887 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 52,881 psi | 81% | 2861 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 51,256 psi | 79% | 2854 fps | 99.9% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 51,909 psi | 80% | 2808 fps | 99.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 42,743 psi | 66% | 2743 fps | 97.6% |
| Somchem S361 | <<locked>> | 80% | 45,672 psi | 70% | 2730 fps | 96.6% |
| Somchem S365 | <<locked>> | 80% | 48,588 psi | 75% | 2825 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 43,729 psi | 67% | 2730 fps | 98.6% |
| Vihtavuori N160 | <<locked>> | 80% | 52,431 psi | 81% | 2861 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 37,985 psi | 58% | 2598 fps | 96.8% |
| Vihtavuori N550 | <<locked>> | 80% | 51,851 psi | 80% | 2864 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 42,743 psi | 66% | 2743 fps | 100% |
| Vihtavuori N560 | 82.1 gr | 80% | 41,742 psi | 64% | 2762 fps | 95.5% |
| Vihtavuori N565 | <<locked>> | 84% | 39,784 psi | 61% | 2700 fps | 95.1% |
| Vihtavuori N568 | <<locked>> | 92% | 46,383 psi | 71% | 2867 fps | 96% |
| Vihtavuori N570 | <<locked>> | 96% | 50,807 psi | 78% | 2986 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 52,025 psi | 80% | 2812 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 54,041 psi | 83% | 2943 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 35,578 psi | 55% | 2697 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 40,118 psi | 62% | 2651 fps | 96.9% |
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 70 powders for .300 Rem. Ultra Mag. loaded with the .308 | 165gr | Remington PSP Core-Lokt. Hodgdon Retumbo delivers the highest muzzle velocity at 3,120 fps; across all powders the maximum-charge window runs from 1,942 fps to 3,120 fps. ADI AR 2217 gives the best case fill at 100 %, and 70 of the 70 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 165.0 gr projectile in 0.308" calls for a 1:6.0 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 | 165gr | Remington PSP Core-Lokt 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.