Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 125gr | Sierra Pro-Hunter 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, IMR 7828 SSC and Norma MRP.
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.
A valid access license is required to use the Personalized Load Calculator.
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% | 54,708 psi | 84% | 3192 fps | 99.6% |
| Accurate 4350 | <<locked>> | 86% | 55,361 psi | 85% | 3248 fps | 100% |
| Accurate MAGPRO | <<locked>> | 94% | 57,580 psi | 89% | 3340 fps | 96.6% |
| ADI AR 2208 | <<locked>> | 82% | 55,956 psi | 86% | 3225 fps | 100% |
| ADI AR 2209 | <<locked>> | 92% | 56,623 psi | 87% | 3291 fps | 98.3% |
| ADI AR 2213 | <<locked>> | 96% | 58,639 psi | 90% | 3353 fps | 97.8% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 44,150 psi | 68% | 3100 fps | 97.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 57,406 psi | 88% | 3251 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 88% | 56,043 psi | 86% | 3310 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 84% | 57,769 psi | 89% | 3330 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 92% | 56,144 psi | 86% | 3278 fps | 98.3% |
| Alliant Reloder-22 | <<locked>> | 96% | 58,624 psi | 90% | 3346 fps | 98.9% |
| Alliant Reloder-23 | <<locked>> | 96% | 55,840 psi | 86% | 3268 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 55,637 psi | 86% | 3317 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 92% | 56,768 psi | 87% | 3353 fps | 100% |
| Bofors RP15 | <<locked>> | 98% | 57,508 psi | 89% | 3327 fps | 98.6% |
| Bofors RP30ᴾ | <<locked>> | 100% | 51,561 psi | 79% | 3232 fps | 97% |
| Bofors RP5 | <<locked>> | 96% | 58,624 psi | 90% | 3346 fps | 98.9% |
| Bofors RP7 | <<locked>> | 86% | 57,682 psi | 89% | 3255 fps | 99.1% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 54,534 psi | 84% | 3258 fps | 98% |
| Hodgdon H414 | <<locked>> | 86% | 57,232 psi | 88% | 3301 fps | 99.4% |
| Hodgdon H4350 | <<locked>> | 84% | 55,912 psi | 86% | 3255 fps | 98.4% |
| Hodgdon H4831 | <<locked>> | 94% | 58,494 psi | 90% | 3287 fps | 97.1% |
| Hodgdon H4831 SC | <<locked>> | 94% | 57,305 psi | 88% | 3268 fps | 96.9% |
| Hodgdon Hybrid 100V | <<locked>> | 90% | 56,565 psi | 87% | 3228 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 54,476 psi | 84% | 3379 fps | 99.1% |
| Hodgdon Superformance | <<locked>> | 86% | 58,610 psi | 90% | 3330 fps | 99.5% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,622 psi | 56% | 2188 fps | 100% |
| IMR 4350 | <<locked>> | 88% | 55,970 psi | 86% | 3228 fps | 99% |
| IMR 4451 Enduron | <<locked>> | 84% | 55,593 psi | 86% | 3222 fps | 99.1% |
| IMR 4831 | <<locked>> | 88% | 55,898 psi | 86% | 3238 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 92% | 55,477 psi | 85% | 3212 fps | 96.7% |
| IMR 7828 SSC | <<locked>> | 96% | 56,318 psi | 87% | 3320 fps | 97.4% |
| Lovex S065 | <<locked>> | 86% | 56,202 psi | 86% | 3219 fps | 99.8% |
| Lovex S070 | <<locked>> | 88% | 58,175 psi | 90% | 3268 fps | 99.6% |
| Lovex S071ᴾ | <<locked>> | 100% | 55,898 psi | 86% | 3209 fps | 99.7% |
| Norma 204 | <<locked>> | 88% | 57,334 psi | 88% | 3281 fps | 98.3% |
| Norma MRP | <<locked>> | 94% | 58,798 psi | 90% | 3373 fps | 99.6% |
| Norma URP | <<locked>> | 88% | 57,566 psi | 89% | 3287 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 57,421 psi | 88% | 3343 fps | 98% |
| Ramshot Hunter | <<locked>> | 88% | 56,782 psi | 87% | 3284 fps | 99.8% |
| Ramshot Magnum | <<locked>> | 98% | 56,231 psi | 87% | 3268 fps | 99.2% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,434 psi | 58% | 2238 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 58,581 psi | 90% | 3261 fps | 99.7% |
| ReloadSwiss RS 60 | <<locked>> | 82% | 56,913 psi | 88% | 3320 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 86% | 55,753 psi | 86% | 3264 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 58,378 psi | 90% | 3356 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 56,057 psi | 86% | 3373 fps | 99.9% |
| Rottweil R 903 | <<locked>> | 82% | 55,288 psi | 85% | 3209 fps | 100% |
| Rottweil R 904 | <<locked>> | 92% | 57,783 psi | 89% | 3261 fps | 97.6% |
| Rottweil R 905 | <<locked>> | 92% | 55,550 psi | 85% | 3264 fps | 98.3% |
| Rottweil R 907 | <<locked>> | 86% | 57,682 psi | 89% | 3255 fps | 99.1% |
| Shooters World Long Rifle | <<locked>> | 86% | 56,202 psi | 86% | 3219 fps | 99.8% |
| Shooters World SW4350 | <<locked>> | 88% | 58,175 psi | 90% | 3268 fps | 99.6% |
| SNPE Vectan SP 11 | <<locked>> | 82% | 57,029 psi | 88% | 3264 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 58,639 psi | 90% | 3136 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 55,695 psi | 86% | 3163 fps | 99.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 55,114 psi | 85% | 3258 fps | 98.2% |
| Somchem S355 | <<locked>> | 84% | 58,639 psi | 90% | 3261 fps | 100% |
| Somchem S361 | <<locked>> | 90% | 56,086 psi | 86% | 3182 fps | 96.7% |
| Somchem S365 | <<locked>> | 90% | 58,247 psi | 90% | 3291 fps | 100% |
| Somchem S385 | <<locked>> | 92% | 56,260 psi | 87% | 3235 fps | 99% |
| Vihtavuori N150 | <<locked>> | 84% | 56,405 psi | 87% | 3173 fps | 100% |
| Vihtavuori N160 | <<locked>> | 86% | 55,535 psi | 85% | 3222 fps | 100% |
| Vihtavuori N165 | <<locked>> | 96% | 56,115 psi | 86% | 3209 fps | 98.8% |
| Vihtavuori N550 | <<locked>> | 86% | 54,998 psi | 85% | 3222 fps | 100% |
| Vihtavuori N555 | <<locked>> | 94% | 57,943 psi | 89% | 3297 fps | 100% |
| Vihtavuori N560 | <<locked>> | 94% | 58,494 psi | 90% | 3360 fps | 97.4% |
| Vihtavuori N565 | <<locked>> | 98% | 54,723 psi | 84% | 3261 fps | 96.9% |
| Winchester 6.5 StaBALL | <<locked>> | 86% | 55,796 psi | 86% | 3173 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 57,421 psi | 88% | 3301 fps | 99.4% |
| Winchester StaBALL HD | <<locked>> | 98% | 58,247 psi | 90% | 3402 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 94% | 56,565 psi | 87% | 3228 fps | 98.4% |
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>> | 82% | 35,781 psi | 55% | 2818 fps | 95.3% |
| Accurate 4350 | <<locked>> | 80% | 44,773 psi | 69% | 3058 fps | 99.2% |
| Accurate MAGPRO | <<locked>> | 92% | 53,563 psi | 82% | 3264 fps | 95.6% |
| ADI AR 2208 | <<locked>> | 80% | 52,591 psi | 81% | 3173 fps | 100% |
| ADI AR 2209 | <<locked>> | 86% | 46,006 psi | 71% | 3097 fps | 95.9% |
| ADI AR 2213 | <<locked>> | 92% | 50,821 psi | 78% | 3212 fps | 96% |
| ADI AR 2225 | <<locked>> | 96% | 38,450 psi | 59% | 2963 fps | 95.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 53,766 psi | 83% | 3196 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 42,511 psi | 65% | 3064 fps | 99.1% |
| Alliant Reloder-17 | <<locked>> | 80% | 49,690 psi | 76% | 3202 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 45,818 psi | 71% | 3087 fps | 95.9% |
| Alliant Reloder-22 | <<locked>> | 88% | 44,179 psi | 68% | 3081 fps | 95.6% |
| Alliant Reloder-23 | <<locked>> | 80% | 31,821 psi | 49% | 2785 fps | 97.4% |
| Alliant Reloder-25 | <<locked>> | 86% | 34,214 psi | 53% | 2858 fps | 95.3% |
| Alliant Reloder-26 | <<locked>> | 80% | 35,099 psi | 54% | 2917 fps | 96.5% |
| Bofors RP15 | <<locked>> | 90% | 43,729 psi | 67% | 3064 fps | 95.2% |
| Bofors RP30 | <<locked>> | 98% | 48,022 psi | 74% | 3163 fps | 96% |
| Bofors RP5 | <<locked>> | 88% | 44,179 psi | 68% | 3081 fps | 95.6% |
| Bofors RP7 | <<locked>> | 80% | 47,529 psi | 73% | 3071 fps | 97.3% |
| Hodgdon H1000 | <<locked>> | 96% | 47,152 psi | 73% | 3117 fps | 96% |
| Hodgdon H414 | <<locked>> | 80% | 46,499 psi | 72% | 3107 fps | 97.6% |
| Hodgdon H4350 | <<locked>> | 80% | 48,863 psi | 75% | 3127 fps | 97% |
| Hodgdon H4831 | <<locked>> | 90% | 50,807 psi | 78% | 3153 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 90% | 49,777 psi | 77% | 3133 fps | 95% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 40,161 psi | 62% | 2943 fps | 99.5% |
| Hodgdon Retumbo | <<locked>> | 92% | 41,031 psi | 63% | 3077 fps | 95% |
| Hodgdon Superformance | <<locked>> | 80% | 46,528 psi | 72% | 3120 fps | 97.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,369 psi | 42% | 1975 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 42,946 psi | 66% | 2982 fps | 96.1% |
| IMR 4451 Enduron | <<locked>> | 80% | 48,878 psi | 75% | 3104 fps | 98% |
| IMR 4831 | <<locked>> | 80% | 42,482 psi | 65% | 2995 fps | 98.8% |
| IMR 4955 Enduron | <<locked>> | 90% | 51,967 psi | 80% | 3150 fps | 95.8% |
| IMR 7828 SSC | 93.6 gr | 92% | 48,747 psi | 75% | 3182 fps | 95.5% |
| Lovex S065 | <<locked>> | 80% | 46,412 psi | 71% | 3045 fps | 98.6% |
| Lovex S070 | <<locked>> | 80% | 44,802 psi | 69% | 3025 fps | 97.4% |
| Lovex S071 | <<locked>> | 88% | 37,347 psi | 57% | 2854 fps | 95.9% |
| Norma 204 | <<locked>> | 82% | 46,296 psi | 71% | 3081 fps | 95.8% |
| Norma MRP | 88.8 gr | 84% | 40,437 psi | 62% | 3022 fps | 95.8% |
| Norma URP | <<locked>> | 80% | 43,845 psi | 67% | 3045 fps | 99% |
| Ramshot Grand | <<locked>> | 92% | 49,240 psi | 76% | 3196 fps | 96.1% |
| Ramshot Hunter | <<locked>> | 80% | 42,917 psi | 66% | 3028 fps | 97.5% |
| Ramshot Magnum | <<locked>> | 90% | 40,944 psi | 63% | 2979 fps | 95.5% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,876 psi | 43% | 2018 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 54,723 psi | 84% | 3202 fps | 99.4% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 52,736 psi | 81% | 3258 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 44,817 psi | 69% | 3071 fps | 99% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 43,105 psi | 66% | 3081 fps | 98.7% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 38,145 psi | 59% | 2982 fps | 95.2% |
| Rottweil R 903 | <<locked>> | 80% | 51,663 psi | 80% | 3153 fps | 100% |
| Rottweil R 904 | <<locked>> | 86% | 47,282 psi | 73% | 3071 fps | 95% |
| Rottweil R 905 | <<locked>> | 86% | 45,179 psi | 70% | 3071 fps | 95.9% |
| Rottweil R 907 | <<locked>> | 80% | 47,529 psi | 73% | 3071 fps | 97.3% |
| Shooters World Long Rifle | <<locked>> | 80% | 46,412 psi | 71% | 3045 fps | 98.6% |
| Shooters World SW4350 | <<locked>> | 80% | 44,802 psi | 69% | 3025 fps | 97.4% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 53,200 psi | 82% | 3205 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 51,677 psi | 80% | 3041 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 45,498 psi | 70% | 2982 fps | 97.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 44,788 psi | 69% | 3064 fps | 95.7% |
| Somchem S355 | <<locked>> | 80% | 51,430 psi | 79% | 3150 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 52,431 psi | 81% | 3120 fps | 95.8% |
| Somchem S365 | <<locked>> | 80% | 40,698 psi | 63% | 2999 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 39,943 psi | 61% | 2923 fps | 95% |
| Vihtavuori N150 | <<locked>> | 80% | 49,342 psi | 76% | 3064 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 45,353 psi | 70% | 3045 fps | 99.2% |
| Vihtavuori N165 | <<locked>> | 88% | 42,583 psi | 66% | 2966 fps | 95.7% |
| Vihtavuori N550 | <<locked>> | 80% | 44,846 psi | 69% | 3041 fps | 99% |
| Vihtavuori N555 | <<locked>> | 80% | 35,708 psi | 55% | 2874 fps | 97.5% |
| Vihtavuori N560 | <<locked>> | 90% | 50,633 psi | 78% | 3219 fps | 95.5% |
| Vihtavuori N565 | <<locked>> | 96% | 50,894 psi | 78% | 3196 fps | 96% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 44,788 psi | 69% | 2995 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 46,644 psi | 72% | 3110 fps | 97.6% |
| Winchester StaBALL HD | 83.7 gr | 80% | 28,413 psi | 44% | 2759 fps | 96.8% |
| Winchester Supreme 780 | <<locked>> | 88% | 45,527 psi | 70% | 3031 fps | 95.9% |
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 80 powders for .300 Rem. Ultra Mag. loaded with the .308 | 125gr | Sierra Pro-Hunter. Winchester StaBALL HD delivers the highest muzzle velocity at 3,402 fps; across all powders the maximum-charge window runs from 2,188 fps to 3,402 fps. ADI AR 2217 gives the best case fill at 100 %, and 80 of the 80 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 56–90 %, leaving at least 10 % headroom. 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, IMR 7828 SSC, Norma MRP rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 125gr | Sierra Pro-Hunter they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, Baschieri & Pellagri 109, IMR 8133 Enduron, Vihtavuori N170 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.