Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 186gr | Peregrine Backup (VRG-2) 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% | 56,637 psi | 87% | 2792 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 57,130 psi | 88% | 2818 fps | 100% |
| Accurate MAGPRO | <<locked>> | 88% | 55,898 psi | 86% | 2894 fps | 99.1% |
| ADI AR 2209 | <<locked>> | 88% | 58,494 psi | 90% | 2884 fps | 100% |
| ADI AR 2213 | <<locked>> | 90% | 56,898 psi | 88% | 2897 fps | 99.7% |
| ADI AR 2217 | <<locked>> | 98% | 55,259 psi | 85% | 2864 fps | 99.8% |
| ADI AR 2218ᴾ | <<locked>> | 100% | 51,909 psi | 80% | 2897 fps | 97.1% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 53,708 psi | 83% | 2881 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 88% | 58,726 psi | 90% | 2881 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 84% | 58,508 psi | 90% | 2874 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 88% | 58,059 psi | 89% | 2874 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 90% | 57,116 psi | 88% | 2890 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 92% | 58,610 psi | 90% | 2848 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 94% | 55,013 psi | 85% | 2864 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 86% | 55,608 psi | 86% | 2884 fps | 100% |
| Alliant Reloder-33ᴾ | <<locked>> | 100% | 57,319 psi | 88% | 2949 fps | 98.1% |
| Baschieri & Pellagri 109 | <<locked>> | 92% | 57,798 psi | 89% | 2854 fps | 98.2% |
| Bofors RP15 | <<locked>> | 92% | 56,289 psi | 87% | 2874 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 58,740 psi | 90% | 2930 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 57,116 psi | 88% | 2890 fps | 100% |
| Bofors RP7 | <<locked>> | 82% | 58,276 psi | 90% | 2818 fps | 100% |
| Hodgdon H1000 | <<locked>> | 96% | 56,913 psi | 88% | 2887 fps | 100% |
| Hodgdon H414 | <<locked>> | 82% | 58,740 psi | 90% | 2871 fps | 100% |
| Hodgdon H4831 | <<locked>> | 88% | 56,028 psi | 86% | 2831 fps | 99.3% |
| Hodgdon H4831 SC | <<locked>> | 88% | 55,013 psi | 85% | 2815 fps | 99.2% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 58,552 psi | 90% | 2792 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 96% | 58,059 psi | 89% | 3002 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,333 psi | 57% | 1827 fps | 100% |
| IMR 4350 | <<locked>> | 84% | 57,000 psi | 88% | 2805 fps | 100% |
| IMR 4831 | <<locked>> | 84% | 57,609 psi | 89% | 2808 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 88% | 56,536 psi | 87% | 2812 fps | 99.4% |
| IMR 7828 SSC | <<locked>> | 90% | 54,969 psi | 85% | 2874 fps | 99.6% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 48,863 psi | 75% | 2795 fps | 99.1% |
| Lovex S065 | <<locked>> | 82% | 57,072 psi | 88% | 2785 fps | 100% |
| Lovex S070 | <<locked>> | 82% | 55,434 psi | 85% | 2785 fps | 100% |
| Lovex S071 | <<locked>> | 96% | 58,305 psi | 90% | 2812 fps | 100% |
| Norma 204 | <<locked>> | 84% | 58,581 psi | 90% | 2867 fps | 100% |
| Norma 217ᴾ | <<locked>> | 100% | 49,821 psi | 77% | 2822 fps | 100% |
| Norma MRP | <<locked>> | 88% | 57,232 psi | 88% | 2907 fps | 100% |
| Norma URP | <<locked>> | 82% | 55,361 psi | 85% | 2799 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 56,115 psi | 86% | 2897 fps | 99.8% |
| Ramshot Hunter | <<locked>> | 84% | 58,392 psi | 90% | 2861 fps | 100% |
| Ramshot Magnum | <<locked>> | 92% | 54,505 psi | 84% | 2825 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,363 psi | 59% | 1873 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 57,551 psi | 89% | 2838 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 82% | 56,231 psi | 87% | 2864 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 94% | 54,984 psi | 85% | 2933 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 96% | 54,273 psi | 84% | 2890 fps | 99.1% |
| Rottweil R 904 | <<locked>> | 86% | 55,317 psi | 85% | 2799 fps | 99.5% |
| Rottweil R 905 | <<locked>> | 88% | 57,537 psi | 89% | 2864 fps | 100% |
| Rottweil R 907 | <<locked>> | 82% | 58,276 psi | 90% | 2818 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 82% | 57,072 psi | 88% | 2785 fps | 100% |
| Shooters World SW4350 | <<locked>> | 82% | 55,434 psi | 85% | 2785 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 82% | 55,985 psi | 86% | 2740 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 88% | 57,174 psi | 88% | 2861 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 56,971 psi | 88% | 2792 fps | 99.4% |
| Somchem S365 | <<locked>> | 84% | 56,652 psi | 87% | 2799 fps | 100% |
| Somchem S385 | <<locked>> | 88% | 58,015 psi | 89% | 2831 fps | 100% |
| Vihtavuori N160 | <<locked>> | 82% | 57,043 psi | 88% | 2792 fps | 100% |
| Vihtavuori N165 | <<locked>> | 92% | 57,856 psi | 89% | 2815 fps | 100% |
| Vihtavuori N170 | <<locked>> | 96% | 57,130 psi | 88% | 2831 fps | 96.5% |
| Vihtavuori N550 | <<locked>> | 82% | 56,304 psi | 87% | 2795 fps | 100% |
| Vihtavuori N555 | <<locked>> | 88% | 56,623 psi | 87% | 2825 fps | 100% |
| Vihtavuori N560 | <<locked>> | 88% | 56,753 psi | 87% | 2907 fps | 99.5% |
| Vihtavuori N565 | <<locked>> | 94% | 57,232 psi | 88% | 2890 fps | 99.7% |
| Vihtavuori N568 | <<locked>> | 96% | 54,824 psi | 84% | 2894 fps | 98.8% |
| Vihtavuori N570 | <<locked>> | 98% | 56,028 psi | 86% | 2953 fps | 97.5% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 56,768 psi | 87% | 2740 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 90% | 54,389 psi | 84% | 2881 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 90% | 58,131 psi | 89% | 2831 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% | 40,016 psi | 62% | 2526 fps | 99.5% |
| Accurate 4350 | <<locked>> | 80% | 53,243 psi | 82% | 2762 fps | 100% |
| Accurate MAGPRO | <<locked>> | 80% | 41,742 psi | 64% | 2644 fps | 95.9% |
| ADI AR 2209 | <<locked>> | 80% | 44,454 psi | 68% | 2661 fps | 98.7% |
| ADI AR 2213 | <<locked>> | 80% | 39,697 psi | 61% | 2595 fps | 96.5% |
| ADI AR 2217 | <<locked>> | 86% | 36,187 psi | 56% | 2510 fps | 95.6% |
| ADI AR 2218 | <<locked>> | 98% | 47,950 psi | 74% | 2822 fps | 95.8% |
| ADI AR 2225 | <<locked>> | 82% | 28,587 psi | 44% | 2349 fps | 95.1% |
| Alliant Power Pro Varmint | <<locked>> | 80% | 44,788 psi | 69% | 2657 fps | 98.8% |
| Alliant Reloder-16 | <<locked>> | 80% | 51,097 psi | 79% | 2769 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 44,367 psi | 68% | 2651 fps | 98.7% |
| Alliant Reloder-22 | <<locked>> | 80% | 40,234 psi | 62% | 2602 fps | 97.9% |
| Alliant Reloder-23 | <<locked>> | 80% | 38,856 psi | 60% | 2549 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 33,547 psi | 52% | 2477 fps | 98.9% |
| Alliant Reloder-26 | <<locked>> | 80% | 44,034 psi | 68% | 2707 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 45,368 psi | 70% | 2746 fps | 95.2% |
| Baschieri & Pellagri 109 | <<locked>> | 84% | 44,498 psi | 68% | 2631 fps | 95% |
| Bofors RP15 | <<locked>> | 80% | 37,420 psi | 58% | 2536 fps | 96.9% |
| Bofors RP30 | <<locked>> | 84% | 35,853 psi | 55% | 2523 fps | 95.7% |
| Bofors RP5 | <<locked>> | 80% | 40,234 psi | 62% | 2602 fps | 97.9% |
| Bofors RP7 | <<locked>> | 80% | 54,737 psi | 84% | 2766 fps | 100% |
| Hodgdon H1000 | <<locked>> | 82% | 34,229 psi | 53% | 2467 fps | 95.4% |
| Hodgdon H414 | <<locked>> | 80% | 54,969 psi | 85% | 2818 fps | 100% |
| Hodgdon H4831 | <<locked>> | 80% | 42,308 psi | 65% | 2598 fps | 96.6% |
| Hodgdon H4831 SC | <<locked>> | 80% | 41,539 psi | 64% | 2582 fps | 96.4% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 47,921 psi | 74% | 2648 fps | 100% |
| Hodgdon Retumbo | 76 gr | 80% | 32,706 psi | 50% | 2503 fps | 95.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,036 psi | 43% | 1640 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 50,169 psi | 77% | 2703 fps | 99.9% |
| IMR 4831 | <<locked>> | 80% | 50,328 psi | 77% | 2707 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 43,584 psi | 67% | 2595 fps | 97.2% |
| IMR 7828 SSC | <<locked>> | 80% | 38,334 psi | 59% | 2575 fps | 96.1% |
| IMR 8133 Enduron | <<locked>> | 92% | 36,767 psi | 57% | 2559 fps | 95.9% |
| Lovex S065 | <<locked>> | 80% | 53,476 psi | 82% | 2733 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 52,069 psi | 80% | 2733 fps | 100% |
| Lovex S071 | <<locked>> | 80% | 34,258 psi | 53% | 2408 fps | 98.3% |
| Norma 204 | <<locked>> | 80% | 50,995 psi | 78% | 2753 fps | 99.5% |
| Norma 217 | <<locked>> | 86% | 29,805 psi | 46% | 2402 fps | 95.1% |
| Norma MRP | <<locked>> | 80% | 42,714 psi | 66% | 2667 fps | 99.4% |
| Norma URP | <<locked>> | 80% | 51,895 psi | 80% | 2749 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 38,145 psi | 59% | 2579 fps | 96.5% |
| Ramshot Hunter | <<locked>> | 80% | 50,966 psi | 78% | 2756 fps | 100% |
| Ramshot Magnum | <<locked>> | 80% | 34,185 psi | 53% | 2461 fps | 96.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,718 psi | 44% | 1680 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 53,621 psi | 83% | 2785 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 52,199 psi | 80% | 2808 fps | 100% |
| ReloadSwiss RS 76 | 81.3 gr | 80% | 31,865 psi | 49% | 2470 fps | 96.9% |
| ReloadSwiss RS 80 | <<locked>> | 88% | 39,523 psi | 61% | 2625 fps | 95.5% |
| Rottweil R 904 | <<locked>> | 80% | 45,310 psi | 70% | 2635 fps | 98.1% |
| Rottweil R 905 | <<locked>> | 80% | 43,758 psi | 67% | 2641 fps | 98.7% |
| Rottweil R 907 | <<locked>> | 80% | 54,737 psi | 84% | 2766 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 80% | 53,476 psi | 82% | 2733 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 52,069 psi | 80% | 2733 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 52,576 psi | 81% | 2690 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 43,424 psi | 67% | 2635 fps | 98.6% |
| Somchem S361 | <<locked>> | 80% | 46,296 psi | 71% | 2621 fps | 97.7% |
| Somchem S365 | <<locked>> | 80% | 49,429 psi | 76% | 2703 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 44,193 psi | 68% | 2618 fps | 99.3% |
| Vihtavuori N160 | <<locked>> | 80% | 53,345 psi | 82% | 2740 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 38,479 psi | 59% | 2497 fps | 97.9% |
| Vihtavuori N170 | <<locked>> | 94% | 53,243 psi | 82% | 2772 fps | 95.6% |
| Vihtavuori N550 | <<locked>> | 80% | 52,562 psi | 81% | 2743 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 43,250 psi | 67% | 2625 fps | 100% |
| Vihtavuori N560 | 78.9 gr | 80% | 42,569 psi | 66% | 2664 fps | 96.9% |
| Vihtavuori N565 | <<locked>> | 82% | 37,521 psi | 58% | 2536 fps | 95.5% |
| Vihtavuori N568 | <<locked>> | 88% | 40,741 psi | 63% | 2641 fps | 95.2% |
| Vihtavuori N570 | <<locked>> | 94% | 48,312 psi | 74% | 2822 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 52,779 psi | 81% | 2690 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 80% | 36,521 psi | 56% | 2592 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 40,654 psi | 63% | 2546 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 70 powders for .300 Rem. Ultra Mag. loaded with the .308 | 186gr | Peregrine Backup (VRG-2). Hodgdon Retumbo delivers the highest muzzle velocity at 3,002 fps; across all powders the maximum-charge window runs from 1,827 fps to 3,002 fps. ADI AR 2218 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 186.0 gr projectile in 0.308" calls for a 1:13.5 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, Vihtavuori N560 rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 186gr | Peregrine Backup (VRG-2) 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.