Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 125gr | Barnes X S bullet and 73 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Winchester StaBALL HD, Norma MRP 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>> | 94% | 57,159 psi | 88% | 3222 fps | 99.7% |
| Accurate 4350 | <<locked>> | 86% | 57,638 psi | 89% | 3274 fps | 100% |
| Accurate High Country | <<locked>> | 92% | 57,769 psi | 89% | 3363 fps | 97.7% |
| ADI AR 2208 | <<locked>> | 82% | 57,290 psi | 88% | 3235 fps | 100% |
| ADI AR 2209 | <<locked>> | 92% | 57,740 psi | 89% | 3307 fps | 98.4% |
| ADI AR 2213 | <<locked>> | 94% | 55,840 psi | 86% | 3297 fps | 97% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 50,604 psi | 78% | 3173 fps | 96.1% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 45,745 psi | 70% | 3130 fps | 98.1% |
| Alliant Power Pro Varmint | <<locked>> | 92% | 58,102 psi | 89% | 3304 fps | 98.4% |
| Alliant Reloder-16 | <<locked>> | 88% | 57,290 psi | 88% | 3327 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 82% | 54,969 psi | 85% | 3284 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 92% | 57,435 psi | 88% | 3294 fps | 98.4% |
| Alliant Reloder-22 | <<locked>> | 94% | 56,173 psi | 86% | 3304 fps | 98.3% |
| Alliant Reloder-23 | <<locked>> | 96% | 57,261 psi | 88% | 3287 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 56,753 psi | 87% | 3333 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 92% | 58,392 psi | 90% | 3379 fps | 100% |
| Bofors RP15 | <<locked>> | 96% | 55,201 psi | 85% | 3284 fps | 98.1% |
| Bofors RP30ᴾ | <<locked>> | 100% | 53,258 psi | 82% | 3261 fps | 97.2% |
| Bofors RP5 | <<locked>> | 94% | 56,173 psi | 86% | 3304 fps | 98.3% |
| Bofors RP7 | <<locked>> | 84% | 55,709 psi | 86% | 3209 fps | 98.7% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 55,680 psi | 86% | 3271 fps | 98% |
| Hodgdon H414 | <<locked>> | 86% | 58,653 psi | 90% | 3314 fps | 99.4% |
| Hodgdon H4350 | <<locked>> | 84% | 57,159 psi | 88% | 3264 fps | 98.4% |
| Hodgdon H4831 | <<locked>> | 92% | 55,767 psi | 86% | 3235 fps | 96.3% |
| Hodgdon H4831 SC | <<locked>> | 94% | 58,407 psi | 90% | 3278 fps | 96.9% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 57,928 psi | 89% | 3241 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 55,680 psi | 86% | 3396 fps | 99.2% |
| Hodgdon Superformance | <<locked>> | 84% | 55,550 psi | 85% | 3278 fps | 99% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,970 psi | 57% | 2182 fps | 100% |
| IMR 4350 | <<locked>> | 88% | 57,145 psi | 88% | 3238 fps | 99% |
| IMR 4451 Enduron | <<locked>> | 84% | 56,623 psi | 87% | 3228 fps | 99.1% |
| IMR 4831 | <<locked>> | 88% | 57,653 psi | 89% | 3258 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 56,594 psi | 87% | 3222 fps | 96.7% |
| IMR 7828 SSC | <<locked>> | 96% | 57,363 psi | 88% | 3333 fps | 97.5% |
| Lovex S065 | <<locked>> | 86% | 58,059 psi | 89% | 3238 fps | 99.8% |
| Lovex S070 | <<locked>> | 86% | 56,275 psi | 87% | 3228 fps | 99.3% |
| Lovex S071ᴾ | <<locked>> | 100% | 58,160 psi | 90% | 3238 fps | 99.8% |
| Norma 204 | <<locked>> | 88% | 58,552 psi | 90% | 3294 fps | 98.4% |
| Norma MRP | <<locked>> | 92% | 55,956 psi | 86% | 3323 fps | 99.2% |
| Norma URP | <<locked>> | 86% | 55,477 psi | 85% | 3251 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 58,465 psi | 90% | 3353 fps | 98% |
| Ramshot Hunter | <<locked>> | 88% | 58,088 psi | 89% | 3297 fps | 99.8% |
| Ramshot Magnum | <<locked>> | 98% | 57,435 psi | 88% | 3281 fps | 99.2% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,884 psi | 58% | 2231 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 58,189 psi | 90% | 3333 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 57,392 psi | 88% | 3284 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 86% | 55,303 psi | 85% | 3304 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 57,479 psi | 88% | 3396 fps | 99.9% |
| Rottweil R 903 | <<locked>> | 82% | 57,377 psi | 88% | 3232 fps | 100% |
| Rottweil R 904 | <<locked>> | 90% | 55,332 psi | 85% | 3215 fps | 96.9% |
| Rottweil R 905 | <<locked>> | 92% | 56,985 psi | 88% | 3281 fps | 98.4% |
| Rottweil R 907 | <<locked>> | 84% | 55,709 psi | 86% | 3209 fps | 98.7% |
| Shooters World Long Rifle | <<locked>> | 86% | 58,059 psi | 89% | 3238 fps | 99.8% |
| Shooters World SW4350 | <<locked>> | 86% | 56,275 psi | 87% | 3228 fps | 99.3% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 58,363 psi | 90% | 3278 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 56,362 psi | 87% | 3100 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 57,435 psi | 88% | 3182 fps | 99.3% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 56,521 psi | 87% | 3278 fps | 98.3% |
| Somchem S355 | <<locked>> | 82% | 56,724 psi | 87% | 3225 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 57,479 psi | 88% | 3192 fps | 96.7% |
| Somchem S365 | <<locked>> | 88% | 55,941 psi | 86% | 3255 fps | 100% |
| Somchem S385 | <<locked>> | 92% | 58,030 psi | 89% | 3255 fps | 99.1% |
| Vihtavuori N150 | <<locked>> | 84% | 57,914 psi | 89% | 3186 fps | 100% |
| Vihtavuori N160 | <<locked>> | 86% | 57,101 psi | 88% | 3238 fps | 100% |
| Vihtavuori N165 | <<locked>> | 96% | 57,348 psi | 88% | 3222 fps | 98.8% |
| Vihtavuori N550 | <<locked>> | 86% | 56,623 psi | 87% | 3245 fps | 100% |
| Vihtavuori N555 | <<locked>> | 92% | 56,115 psi | 86% | 3268 fps | 100% |
| Vihtavuori N560 | <<locked>> | 92% | 55,637 psi | 86% | 3307 fps | 96.6% |
| Vihtavuori N565 | <<locked>> | 98% | 56,434 psi | 87% | 3287 fps | 97.1% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 56,898 psi | 88% | 3182 fps | 100% |
| Winchester 760 | <<locked>> | 84% | 55,158 psi | 85% | 3258 fps | 99.1% |
| Winchester StaBALL HD | <<locked>> | 96% | 55,129 psi | 85% | 3363 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 94% | 57,928 psi | 89% | 3245 fps | 98.5% |
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% | 36,027 psi | 55% | 2815 fps | 95.3% |
| Accurate 4350 | <<locked>> | 80% | 47,195 psi | 73% | 3097 fps | 99.4% |
| Accurate High Country | <<locked>> | 88% | 50,299 psi | 77% | 3225 fps | 95.9% |
| ADI AR 2208 | <<locked>> | 80% | 53,896 psi | 83% | 3182 fps | 100% |
| ADI AR 2209 | <<locked>> | 84% | 44,396 psi | 68% | 3054 fps | 95.1% |
| ADI AR 2213 | <<locked>> | 90% | 48,805 psi | 75% | 3166 fps | 95.1% |
| ADI AR 2217 | <<locked>> | 98% | 47,427 psi | 73% | 3107 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 94% | 37,855 psi | 58% | 2936 fps | 95% |
| Alliant Power Pro Varmint | <<locked>> | 84% | 44,759 psi | 69% | 3054 fps | 95.3% |
| Alliant Reloder-16 | <<locked>> | 80% | 44,077 psi | 68% | 3091 fps | 99.3% |
| Alliant Reloder-17 | <<locked>> | 80% | 51,155 psi | 79% | 3225 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 44,353 psi | 68% | 3048 fps | 95.2% |
| Alliant Reloder-22 | <<locked>> | 88% | 45,905 psi | 71% | 3110 fps | 95.9% |
| Alliant Reloder-23 | <<locked>> | 80% | 33,924 psi | 52% | 2838 fps | 98.1% |
| Alliant Reloder-25 | <<locked>> | 84% | 33,924 psi | 52% | 2844 fps | 95% |
| Alliant Reloder-26 | <<locked>> | 80% | 37,376 psi | 58% | 2976 fps | 97.4% |
| Bofors RP15 | <<locked>> | 90% | 45,513 psi | 70% | 3100 fps | 95.7% |
| Bofors RP30 | <<locked>> | 96% | 46,412 psi | 71% | 3130 fps | 95.3% |
| Bofors RP5 | <<locked>> | 88% | 45,905 psi | 71% | 3110 fps | 95.9% |
| Bofors RP7 | <<locked>> | 80% | 49,124 psi | 76% | 3091 fps | 97.5% |
| Hodgdon H1000 | <<locked>> | 94% | 45,498 psi | 70% | 3074 fps | 95.2% |
| Hodgdon H414 | <<locked>> | 80% | 48,211 psi | 74% | 3133 fps | 97.9% |
| Hodgdon H4350 | <<locked>> | 80% | 50,401 psi | 78% | 3146 fps | 97.1% |
| Hodgdon H4831 | <<locked>> | 90% | 52,112 psi | 80% | 3169 fps | 95.4% |
| Hodgdon H4831 SC | <<locked>> | 90% | 51,068 psi | 79% | 3150 fps | 95.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 41,989 psi | 65% | 2972 fps | 99.7% |
| Hodgdon Retumbo | <<locked>> | 92% | 42,801 psi | 66% | 3120 fps | 95.6% |
| Hodgdon Superformance | <<locked>> | 80% | 48,022 psi | 74% | 3143 fps | 97.6% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,775 psi | 43% | 1969 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 44,585 psi | 69% | 3009 fps | 96.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 50,212 psi | 77% | 3120 fps | 98.1% |
| IMR 4831 | <<locked>> | 80% | 44,628 psi | 69% | 3035 fps | 99.1% |
| IMR 4955 Enduron | <<locked>> | 88% | 50,038 psi | 77% | 3104 fps | 95% |
| IMR 7828 SSC | <<locked>> | 92% | 50,241 psi | 77% | 3205 fps | 95.7% |
| Lovex S065 | <<locked>> | 80% | 48,298 psi | 74% | 3074 fps | 98.8% |
| Lovex S070 | <<locked>> | 80% | 46,673 psi | 72% | 3054 fps | 97.7% |
| Lovex S071 | <<locked>> | 84% | 35,317 psi | 54% | 2795 fps | 95% |
| Norma 204 | <<locked>> | 80% | 44,744 psi | 69% | 3041 fps | 95.1% |
| Norma MRP | 84.2 gr | 82% | 39,523 psi | 61% | 2999 fps | 95.3% |
| Norma URP | <<locked>> | 80% | 45,600 psi | 70% | 3074 fps | 99.2% |
| Ramshot Grand | <<locked>> | 90% | 47,152 psi | 73% | 3146 fps | 95.2% |
| Ramshot Hunter | <<locked>> | 80% | 44,672 psi | 69% | 3058 fps | 97.8% |
| Ramshot Magnum | <<locked>> | 90% | 42,757 psi | 66% | 3015 fps | 96% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,384 psi | 44% | 2014 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 54,070 psi | 83% | 3274 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 46,905 psi | 72% | 3107 fps | 99.3% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 44,744 psi | 69% | 3110 fps | 98.9% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 40,176 psi | 62% | 3035 fps | 96% |
| Rottweil R 903 | <<locked>> | 80% | 53,737 psi | 83% | 3176 fps | 100% |
| Rottweil R 904 | <<locked>> | 86% | 48,747 psi | 75% | 3091 fps | 95.2% |
| Rottweil R 905 | <<locked>> | 84% | 43,859 psi | 68% | 3035 fps | 95.2% |
| Rottweil R 907 | <<locked>> | 80% | 49,124 psi | 76% | 3091 fps | 97.5% |
| Shooters World Long Rifle | <<locked>> | 80% | 48,298 psi | 74% | 3074 fps | 98.8% |
| Shooters World SW4350 | <<locked>> | 80% | 46,673 psi | 72% | 3054 fps | 97.7% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 54,752 psi | 84% | 3225 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 53,011 psi | 82% | 3051 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 47,485 psi | 73% | 3009 fps | 97.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 43,482 psi | 67% | 3031 fps | 95.1% |
| Somchem S355 | <<locked>> | 80% | 53,330 psi | 82% | 3173 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 50,386 psi | 78% | 3071 fps | 95% |
| Somchem S365 | <<locked>> | 80% | 42,801 psi | 66% | 3038 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 41,959 psi | 65% | 2959 fps | 95.6% |
| Vihtavuori N150 | <<locked>> | 80% | 51,024 psi | 79% | 3084 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 47,050 psi | 72% | 3071 fps | 99.4% |
| Vihtavuori N165 | <<locked>> | 86% | 41,495 psi | 64% | 2933 fps | 95.1% |
| Vihtavuori N550 | <<locked>> | 80% | 46,746 psi | 72% | 3071 fps | 99.2% |
| Vihtavuori N555 | <<locked>> | 80% | 38,232 psi | 59% | 2933 fps | 98.2% |
| Vihtavuori N560 | 92.4 gr | 90% | 51,996 psi | 80% | 3241 fps | 95.7% |
| Vihtavuori N565 | <<locked>> | 94% | 49,356 psi | 76% | 3159 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 46,340 psi | 71% | 3018 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 48,211 psi | 74% | 3133 fps | 97.9% |
| Winchester StaBALL HD | 81.3 gr | 80% | 30,748 psi | 47% | 2838 fps | 98.2% |
| Winchester Supreme 780 | <<locked>> | 86% | 44,034 psi | 68% | 2995 fps | 95.2% |
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 73 powders for .300 Rem. Ultra Mag. loaded with the .308 | 125gr | Barnes X S. Hodgdon Retumbo delivers the highest muzzle velocity at 3,396 fps; across all powders the maximum-charge window runs from 2,182 fps to 3,396 fps. ADI AR 2217 gives the best case fill at 100 %, and 73 of the 73 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 125.0 gr projectile in 0.308" calls for a 1:15.0 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Alliant Reloder-25 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. Winchester StaBALL HD, Norma MRP, Vihtavuori N560 rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 125gr | Barnes X S 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.