Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 176gr | Peregrine Glider GRM bullet and 73 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 Winchester StaBALL HD.
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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You can find more information in our FAQ: How can I use the Personalized Load Calculator?
Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 94% | 58,798 psi | 90% | 2881 fps | 100% |
| Accurate 4350 | <<locked>> | 84% | 55,579 psi | 86% | 2861 fps | 100% |
| Accurate MAGPRO | <<locked>> | 92% | 57,870 psi | 89% | 2982 fps | 98.8% |
| ADI AR 2209 | <<locked>> | 90% | 57,058 psi | 88% | 2923 fps | 99.8% |
| ADI AR 2213 | <<locked>> | 92% | 54,926 psi | 85% | 2927 fps | 99.1% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 53,040 psi | 82% | 2887 fps | 99.2% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 47,601 psi | 73% | 2848 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 86% | 56,913 psi | 88% | 2920 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 82% | 58,073 psi | 89% | 2927 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 56,434 psi | 87% | 2910 fps | 99.7% |
| Alliant Reloder-22 | <<locked>> | 92% | 55,071 psi | 85% | 2920 fps | 99.7% |
| Alliant Reloder-23 | <<locked>> | 94% | 56,536 psi | 87% | 2890 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 56,246 psi | 87% | 2949 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 90% | 57,363 psi | 88% | 2976 fps | 100% |
| Baschieri & Pellagri 109 | <<locked>> | 94% | 56,521 psi | 87% | 2887 fps | 97.2% |
| Bofors RP15 | <<locked>> | 96% | 58,073 psi | 89% | 2963 fps | 99.9% |
| Bofors RP30ᴾ | <<locked>> | 100% | 56,014 psi | 86% | 2953 fps | 99.6% |
| Bofors RP5 | <<locked>> | 92% | 55,071 psi | 85% | 2920 fps | 99.7% |
| Bofors RP7 | <<locked>> | 84% | 57,580 psi | 89% | 2864 fps | 100% |
| Hodgdon H1000 | <<locked>> | 98% | 54,781 psi | 84% | 2913 fps | 99.7% |
| Hodgdon H414 | <<locked>> | 84% | 57,493 psi | 88% | 2917 fps | 100% |
| Hodgdon H4350 | <<locked>> | 82% | 56,115 psi | 86% | 2874 fps | 99.8% |
| Hodgdon H4831 | <<locked>> | 92% | 58,653 psi | 90% | 2923 fps | 99.1% |
| Hodgdon H4831 SC | <<locked>> | 92% | 57,334 psi | 88% | 2904 fps | 98.9% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 57,232 psi | 88% | 2838 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 55,187 psi | 85% | 3025 fps | 100% |
| Hodgdon Superformance | <<locked>> | 84% | 58,566 psi | 90% | 2953 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,086 psi | 57% | 1854 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 56,072 psi | 86% | 2851 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 82% | 55,666 psi | 86% | 2838 fps | 100% |
| IMR 4831 | <<locked>> | 86% | 56,072 psi | 86% | 2851 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 55,521 psi | 85% | 2851 fps | 98.8% |
| IMR 7828 SSC | <<locked>> | 94% | 56,898 psi | 88% | 2963 fps | 99.4% |
| IMR 8133 Enduronᴾ | <<locked>> | 100% | 43,004 psi | 66% | 2749 fps | 97.3% |
| Lovex S065 | <<locked>> | 84% | 56,260 psi | 87% | 2831 fps | 100% |
| Lovex S070 | <<locked>> | 86% | 58,189 psi | 90% | 2881 fps | 100% |
| Lovex S071 | <<locked>> | 98% | 56,144 psi | 86% | 2844 fps | 100% |
| Norma 204 | <<locked>> | 86% | 57,450 psi | 88% | 2907 fps | 99.7% |
| Norma 217ᴾ | <<locked>> | 100% | 43,294 psi | 67% | 2776 fps | 99.2% |
| Norma MRP | <<locked>> | 90% | 55,201 psi | 85% | 2943 fps | 100% |
| Norma URP | <<locked>> | 86% | 57,928 psi | 89% | 2897 fps | 100% |
| Ramshot Grand | <<locked>> | 94% | 58,102 psi | 89% | 2986 fps | 99.7% |
| Ramshot Hunter | <<locked>> | 86% | 57,072 psi | 88% | 2904 fps | 100% |
| Ramshot Magnum | <<locked>> | 96% | 56,521 psi | 87% | 2913 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,927 psi | 58% | 1896 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 56,130 psi | 86% | 2884 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 84% | 54,679 psi | 84% | 2913 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 56,289 psi | 87% | 3018 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 55,753 psi | 86% | 2976 fps | 98.8% |
| Rottweil R 904 | <<locked>> | 90% | 57,928 psi | 89% | 2890 fps | 99.4% |
| Rottweil R 905 | <<locked>> | 90% | 55,970 psi | 86% | 2900 fps | 99.8% |
| Rottweil R 907 | <<locked>> | 84% | 57,580 psi | 89% | 2864 fps | 100% |
| Shooters World Long Rifle | <<locked>> | 84% | 56,260 psi | 87% | 2831 fps | 100% |
| Shooters World SW4350 | <<locked>> | 86% | 58,189 psi | 90% | 2881 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 58,436 psi | 90% | 2730 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 55,463 psi | 85% | 2785 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 55,550 psi | 85% | 2894 fps | 99.7% |
| Somchem S355 | <<locked>> | 82% | 58,537 psi | 90% | 2851 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 55,898 psi | 86% | 2825 fps | 98.7% |
| Somchem S365 | <<locked>> | 86% | 54,955 psi | 85% | 2848 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 56,420 psi | 87% | 2871 fps | 100% |
| Vihtavuori N150 | <<locked>> | 82% | 56,260 psi | 87% | 2776 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 55,825 psi | 86% | 2835 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 56,231 psi | 87% | 2851 fps | 99.9% |
| Vihtavuori N550 | <<locked>> | 84% | 55,172 psi | 85% | 2841 fps | 100% |
| Vihtavuori N555 | <<locked>> | 92% | 58,436 psi | 90% | 2917 fps | 100% |
| Vihtavuori N560 | <<locked>> | 92% | 58,798 psi | 90% | 2999 fps | 99.3% |
| Vihtavuori N565 | <<locked>> | 96% | 55,042 psi | 85% | 2917 fps | 99% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 56,202 psi | 86% | 2976 fps | 98.4% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 55,695 psi | 86% | 2792 fps | 100% |
| Winchester 760 | <<locked>> | 84% | 57,711 psi | 89% | 2920 fps | 100% |
| Winchester StaBALL HD | <<locked>> | 94% | 55,303 psi | 85% | 2969 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 56,550 psi | 87% | 2867 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% | 35,911 psi | 55% | 2497 fps | 98.1% |
| Accurate 4350 | <<locked>> | 80% | 48,269 psi | 74% | 2753 fps | 100% |
| Accurate MAGPRO | <<locked>> | 84% | 43,221 psi | 67% | 2730 fps | 95.5% |
| ADI AR 2209 | <<locked>> | 80% | 40,234 psi | 62% | 2631 fps | 97% |
| ADI AR 2213 | <<locked>> | 82% | 38,508 psi | 59% | 2618 fps | 95% |
| ADI AR 2217 | <<locked>> | 90% | 37,507 psi | 58% | 2585 fps | 95% |
| ADI AR 2225 | <<locked>> | 88% | 31,531 psi | 49% | 2484 fps | 95.8% |
| Alliant Reloder-16 | <<locked>> | 80% | 46,528 psi | 72% | 2766 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 80% | 54,201 psi | 83% | 2874 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 40,292 psi | 62% | 2628 fps | 97% |
| Alliant Reloder-22 | <<locked>> | 80% | 36,114 psi | 56% | 2566 fps | 95.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 34,795 psi | 54% | 2530 fps | 99.9% |
| Alliant Reloder-25 | <<locked>> | 80% | 29,994 psi | 46% | 2438 fps | 96.8% |
| Alliant Reloder-26 | <<locked>> | 80% | 38,653 psi | 59% | 2671 fps | 99.7% |
| Baschieri & Pellagri 109 | <<locked>> | 90% | 49,719 psi | 77% | 2772 fps | 95.5% |
| Bofors RP15 | <<locked>> | 82% | 35,926 psi | 55% | 2559 fps | 95.5% |
| Bofors RP30 | <<locked>> | 88% | 36,506 psi | 56% | 2595 fps | 95.1% |
| Bofors RP5 | <<locked>> | 80% | 36,114 psi | 56% | 2566 fps | 95.7% |
| Bofors RP7 | <<locked>> | 80% | 50,618 psi | 78% | 2759 fps | 99.6% |
| Hodgdon H1000 | <<locked>> | 88% | 38,247 psi | 59% | 2608 fps | 96.1% |
| Hodgdon H414 | <<locked>> | 80% | 50,140 psi | 77% | 2805 fps | 99.8% |
| Hodgdon H4350 | <<locked>> | 80% | 52,533 psi | 81% | 2822 fps | 99.5% |
| Hodgdon H4831 | <<locked>> | 82% | 41,205 psi | 63% | 2628 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 82% | 40,422 psi | 62% | 2612 fps | 95% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 43,656 psi | 67% | 2641 fps | 100% |
| Hodgdon Retumbo | 75.9 gr | 84% | 33,634 psi | 52% | 2579 fps | 95.2% |
| Hodgdon Superformance | <<locked>> | 80% | 50,473 psi | 78% | 2831 fps | 99.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,659 psi | 43% | 1660 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 46,050 psi | 71% | 2690 fps | 99.1% |
| IMR 4451 Enduron | <<locked>> | 80% | 52,185 psi | 80% | 2782 fps | 99.8% |
| IMR 4831 | <<locked>> | 80% | 45,963 psi | 71% | 2700 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 39,943 psi | 61% | 2572 fps | 95.1% |
| IMR 7828 SSC | <<locked>> | 84% | 39,885 psi | 61% | 2661 fps | 95.7% |
| IMR 8133 Enduron | <<locked>> | 96% | 37,333 psi | 57% | 2628 fps | 95.2% |
| Lovex S065 | <<locked>> | 80% | 49,545 psi | 76% | 2733 fps | 100% |
| Lovex S070 | <<locked>> | 80% | 47,964 psi | 74% | 2723 fps | 99.7% |
| Lovex S071 | <<locked>> | 80% | 30,705 psi | 47% | 2375 fps | 96.3% |
| Norma 204 | <<locked>> | 80% | 46,499 psi | 72% | 2733 fps | 98.4% |
| Norma 217 | <<locked>> | 92% | 32,474 psi | 50% | 2530 fps | 95.6% |
| Norma MRP | <<locked>> | 80% | 38,116 psi | 59% | 2635 fps | 97.8% |
| Norma URP | <<locked>> | 80% | 47,427 psi | 73% | 2743 fps | 100% |
| Ramshot Grand | <<locked>> | 84% | 39,668 psi | 61% | 2664 fps | 96.1% |
| Ramshot Hunter | <<locked>> | 80% | 46,383 psi | 71% | 2740 fps | 99.8% |
| Ramshot Magnum | <<locked>> | 82% | 32,721 psi | 50% | 2477 fps | 95.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,311 psi | 44% | 1703 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 48,617 psi | 75% | 2776 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 46,934 psi | 72% | 2792 fps | 100% |
| ReloadSwiss RS 76 | 79.4 gr | 82% | 30,661 psi | 47% | 2484 fps | 95% |
| ReloadSwiss RS 80 | <<locked>> | 94% | 43,743 psi | 67% | 2769 fps | 96.1% |
| Rottweil R 904 | <<locked>> | 80% | 41,510 psi | 64% | 2612 fps | 96.2% |
| Rottweil R 905 | <<locked>> | 80% | 39,668 psi | 61% | 2615 fps | 97% |
| Rottweil R 907 | <<locked>> | 80% | 50,618 psi | 78% | 2759 fps | 99.6% |
| Shooters World Long Rifle | <<locked>> | 80% | 49,545 psi | 76% | 2733 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 47,964 psi | 74% | 2723 fps | 99.7% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 54,897 psi | 84% | 2684 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 48,530 psi | 75% | 2680 fps | 99.7% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 39,334 psi | 61% | 2608 fps | 96.9% |
| Somchem S355 | <<locked>> | 80% | 55,027 psi | 85% | 2805 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 42,366 psi | 65% | 2598 fps | 95.7% |
| Somchem S365 | <<locked>> | 80% | 44,440 psi | 68% | 2694 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 40,118 psi | 62% | 2592 fps | 97.9% |
| Vihtavuori N150 | <<locked>> | 80% | 52,808 psi | 81% | 2730 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 48,762 psi | 75% | 2733 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 34,737 psi | 53% | 2467 fps | 95.8% |
| Vihtavuori N550 | <<locked>> | 80% | 48,196 psi | 74% | 2736 fps | 100% |
| Vihtavuori N555 | <<locked>> | 80% | 38,827 psi | 60% | 2605 fps | 99.9% |
| Vihtavuori N560 | <<locked>> | 82% | 40,988 psi | 63% | 2687 fps | 95.5% |
| Vihtavuori N565 | <<locked>> | 88% | 41,452 psi | 64% | 2677 fps | 96% |
| Vihtavuori N568 | <<locked>> | 94% | 45,005 psi | 69% | 2785 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 48,254 psi | 74% | 2690 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 50,328 psi | 77% | 2808 fps | 99.8% |
| Winchester StaBALL HD | 74.3 gr | 80% | 31,241 psi | 48% | 2549 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 36,825 psi | 57% | 2520 fps | 96% |
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 79 powders for .300 Rem. Ultra Mag. loaded with the .308 | 176gr | Peregrine Glider GRM. Hodgdon Retumbo delivers the highest muzzle velocity at 3,025 fps; across all powders the maximum-charge window runs from 1,854 fps to 3,025 fps. ADI AR 2217 gives the best case fill at 100 %, and 79 of the 79 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 176.0 gr projectile in 0.308" calls for a 1:10.0 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, ReloadSwiss RS 76, Winchester StaBALL HD rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 176gr | Peregrine Glider GRM they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, ADI AR 2218, Alliant Reloder-50, IMR 7977 Enduron 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.