Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 115gr | Sierra VarmintKing bullet and 81 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-26, Alliant Reloder-16 and Winchester 760.
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 2700 | <<locked>> | 82% | 56,507 psi | 87% | 3278 fps | 98.1% |
| Accurate 3100 | <<locked>> | 98% | 57,232 psi | 88% | 3317 fps | 99.5% |
| Accurate 4064 | <<locked>> | 82% | 55,898 psi | 86% | 3284 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 58,131 psi | 89% | 3386 fps | 100% |
| ADI AR 2208 | <<locked>> | 84% | 55,622 psi | 86% | 3314 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 55,535 psi | 85% | 3360 fps | 97.3% |
| ADI AR 2213 | <<locked>> | 98% | 57,305 psi | 88% | 3409 fps | 96.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 56,855 psi | 88% | 3340 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 56,898 psi | 88% | 3363 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 58,595 psi | 90% | 3448 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 56,333 psi | 87% | 3409 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 58,798 psi | 90% | 3406 fps | 98% |
| Alliant Reloder-22 | <<locked>> | 98% | 56,898 psi | 88% | 3409 fps | 97.9% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 57,696 psi | 89% | 3396 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 49,995 psi | 77% | 3307 fps | 99.4% |
| Alliant Reloder-26 | <<locked>> | 94% | 54,592 psi | 84% | 3415 fps | 99.9% |
| Bofors RP15ᴾ | <<locked>> | 100% | 55,825 psi | 86% | 3383 fps | 97.5% |
| Bofors RP3 | <<locked>> | 84% | 58,073 psi | 89% | 3353 fps | 100% |
| Bofors RP5 | <<locked>> | 98% | 56,898 psi | 88% | 3409 fps | 97.9% |
| Bofors RP7 | <<locked>> | 88% | 57,276 psi | 88% | 3330 fps | 98.4% |
| Hodgdon H380 | <<locked>> | 84% | 58,334 psi | 90% | 3369 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 88% | 56,231 psi | 87% | 3373 fps | 98.8% |
| Hodgdon H4350 | <<locked>> | 86% | 55,274 psi | 85% | 3330 fps | 97.5% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 55,216 psi | 85% | 3304 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 48,979 psi | 75% | 3343 fps | 96.9% |
| Hodgdon Superformance | <<locked>> | 88% | 57,522 psi | 89% | 3406 fps | 98.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,245 psi | 56% | 2251 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 58,537 psi | 90% | 3353 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 57,392 psi | 88% | 3323 fps | 98.8% |
| IMR 4350 | <<locked>> | 90% | 55,100 psi | 85% | 3297 fps | 98.1% |
| IMR 4451 Enduron | <<locked>> | 88% | 58,740 psi | 90% | 3363 fps | 99% |
| IMR 4831 | <<locked>> | 92% | 58,523 psi | 90% | 3369 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 58,407 psi | 90% | 3399 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 58,392 psi | 90% | 3340 fps | 96.3% |
| IMR 7828 SSC | <<locked>> | 98% | 54,781 psi | 84% | 3376 fps | 96.1% |
| Lovex S062 | <<locked>> | 82% | 55,317 psi | 85% | 3294 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 55,651 psi | 86% | 3301 fps | 99.4% |
| Lovex S070 | <<locked>> | 90% | 57,406 psi | 88% | 3343 fps | 99% |
| Lovex S071ᴾ | <<locked>> | 100% | 50,531 psi | 78% | 3209 fps | 98.6% |
| Norma 203B | <<locked>> | 82% | 56,202 psi | 86% | 3346 fps | 100% |
| Norma 204 | <<locked>> | 90% | 56,376 psi | 87% | 3353 fps | 97.3% |
| Norma MRP | <<locked>> | 96% | 56,869 psi | 88% | 3435 fps | 99% |
| Norma URP | <<locked>> | 90% | 56,492 psi | 87% | 3366 fps | 99.9% |
| Ramshot Big Game | <<locked>> | 82% | 57,537 psi | 89% | 3363 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 55,550 psi | 85% | 3392 fps | 96.7% |
| Ramshot Hunter | <<locked>> | 90% | 55,608 psi | 86% | 3353 fps | 99.2% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 54,346 psi | 84% | 3320 fps | 98.2% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,985 psi | 57% | 2303 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 58,088 psi | 89% | 3343 fps | 99.3% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 55,651 psi | 86% | 3406 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 58,595 psi | 90% | 3402 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 56,942 psi | 88% | 3428 fps | 99.9% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 50,067 psi | 77% | 3340 fps | 98.4% |
| Rottweil R 902 | <<locked>> | 82% | 57,159 psi | 88% | 3310 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 58,276 psi | 90% | 3350 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 56,768 psi | 87% | 3327 fps | 96.5% |
| Rottweil R 905 | <<locked>> | 96% | 58,131 psi | 89% | 3396 fps | 98% |
| Rottweil R 907 | <<locked>> | 88% | 57,276 psi | 88% | 3330 fps | 98.4% |
| Shooters World Long Rifle | <<locked>> | 88% | 55,651 psi | 86% | 3301 fps | 99.4% |
| Shooters World Precision | <<locked>> | 82% | 55,317 psi | 85% | 3294 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 57,406 psi | 88% | 3343 fps | 99% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 56,188 psi | 86% | 3346 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 58,291 psi | 90% | 3228 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 55,201 psi | 85% | 3238 fps | 98.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 57,653 psi | 89% | 3389 fps | 97.9% |
| Somchem S355 | <<locked>> | 86% | 57,725 psi | 89% | 3343 fps | 100% |
| Somchem S365 | <<locked>> | 92% | 56,579 psi | 87% | 3369 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 55,143 psi | 85% | 3304 fps | 98.2% |
| Vihtavuori N135 | <<locked>> | 82% | 57,522 psi | 89% | 3268 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 57,943 psi | 89% | 3274 fps | 100% |
| Vihtavuori N150 | <<locked>> | 86% | 55,767 psi | 86% | 3258 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 58,450 psi | 90% | 3356 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 58,711 psi | 90% | 3333 fps | 98.5% |
| Vihtavuori N540 | <<locked>> | 82% | 56,347 psi | 87% | 3264 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 57,783 psi | 89% | 3360 fps | 99.9% |
| Vihtavuori N555 | <<locked>> | 96% | 56,144 psi | 86% | 3369 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 56,782 psi | 87% | 3419 fps | 96.1% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 54,810 psi | 84% | 3251 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 56,405 psi | 87% | 3376 fps | 98.8% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 55,143 psi | 85% | 3468 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 55,448 psi | 85% | 3291 fps | 97.4% |
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 2700 | <<locked>> | 80% | 52,649 psi | 81% | 3215 fps | 97.4% |
| Accurate 3100 | <<locked>> | 88% | 40,030 psi | 62% | 2999 fps | 95.9% |
| Accurate 4064 | <<locked>> | 80% | 52,344 psi | 81% | 3228 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 40,538 psi | 62% | 3058 fps | 97.6% |
| ADI AR 2208 | <<locked>> | 80% | 48,907 psi | 75% | 3196 fps | 99.5% |
| ADI AR 2209 | <<locked>> | 90% | 48,167 psi | 74% | 3225 fps | 95.5% |
| ADI AR 2213 | <<locked>> | 96% | 53,345 psi | 82% | 3340 fps | 95.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 49,719 psi | 77% | 3225 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 53,185 psi | 82% | 3301 fps | 99.9% |
| Alliant Reloder-16 | 76.6 gr | 80% | 38,827 psi | 60% | 3068 fps | 97.5% |
| Alliant Reloder-17 | <<locked>> | 80% | 44,962 psi | 69% | 3212 fps | 99.8% |
| Alliant Reloder-19 | <<locked>> | 90% | 47,993 psi | 74% | 3212 fps | 95.5% |
| Alliant Reloder-22 | <<locked>> | 92% | 46,064 psi | 71% | 3202 fps | 95.1% |
| Alliant Reloder-23 | <<locked>> | 82% | 30,792 psi | 47% | 2835 fps | 95.9% |
| Alliant Reloder-25 | <<locked>> | 92% | 38,000 psi | 58% | 3038 fps | 96% |
| Alliant Reloder-26 | 88.8 gr | 84% | 36,622 psi | 56% | 3038 fps | 96.1% |
| Bofors RP15 | <<locked>> | 96% | 48,588 psi | 75% | 3251 fps | 95.8% |
| Bofors RP3 | <<locked>> | 80% | 50,502 psi | 78% | 3235 fps | 100% |
| Bofors RP5 | <<locked>> | 92% | 46,064 psi | 71% | 3202 fps | 95.1% |
| Bofors RP7 | <<locked>> | 80% | 43,903 psi | 68% | 3077 fps | 95.3% |
| Hodgdon H380 | <<locked>> | 80% | 50,792 psi | 78% | 3245 fps | 99.2% |
| Hodgdon H414 | <<locked>> | 80% | 42,395 psi | 65% | 3104 fps | 95.4% |
| Hodgdon H4350 | <<locked>> | 82% | 48,240 psi | 74% | 3199 fps | 95.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 36,448 psi | 56% | 2946 fps | 98.1% |
| Hodgdon Retumbo | <<locked>> | 98% | 45,629 psi | 70% | 3268 fps | 95.7% |
| Hodgdon Superformance | <<locked>> | 80% | 41,916 psi | 65% | 3107 fps | 95% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,035 psi | 42% | 2034 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 51,416 psi | 79% | 3238 fps | 99.8% |
| IMR 4166 Enduron | <<locked>> | 80% | 53,867 psi | 83% | 3264 fps | 98.2% |
| IMR 4350 | <<locked>> | 84% | 45,310 psi | 70% | 3117 fps | 95.8% |
| IMR 4451 Enduron | <<locked>> | 80% | 45,324 psi | 70% | 3114 fps | 96.2% |
| IMR 4831 | <<locked>> | 80% | 38,754 psi | 60% | 3002 fps | 97.2% |
| IMR 4895 | <<locked>> | 80% | 54,578 psi | 84% | 3337 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 54,781 psi | 84% | 3278 fps | 95.5% |
| IMR 7828 SSC | <<locked>> | 96% | 50,981 psi | 78% | 3304 fps | 95% |
| Lovex S062 | <<locked>> | 80% | 51,706 psi | 80% | 3235 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 42,931 psi | 66% | 3058 fps | 97% |
| Lovex S070 | <<locked>> | 80% | 41,162 psi | 63% | 3031 fps | 95.3% |
| Lovex S071 | <<locked>> | 92% | 38,566 psi | 59% | 2963 fps | 95.4% |
| Norma 203B | <<locked>> | 80% | 52,533 psi | 81% | 3287 fps | 100% |
| Norma 204 | <<locked>> | 86% | 48,791 psi | 75% | 3215 fps | 95.5% |
| Norma MRP | <<locked>> | 88% | 42,134 psi | 65% | 3146 fps | 95.4% |
| Norma URP | <<locked>> | 80% | 39,958 psi | 61% | 3048 fps | 97.3% |
| Ramshot Big Game | <<locked>> | 80% | 53,577 psi | 82% | 3301 fps | 100% |
| Ramshot Grand | <<locked>> | 96% | 51,517 psi | 79% | 3317 fps | 95.6% |
| Ramshot Hunter | <<locked>> | 80% | 39,015 psi | 60% | 3022 fps | 95.2% |
| Ramshot Magnum | <<locked>> | 94% | 42,975 psi | 66% | 3100 fps | 95.1% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,499 psi | 42% | 2080 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 50,647 psi | 78% | 3219 fps | 98.2% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 47,732 psi | 73% | 3278 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 40,509 psi | 62% | 3064 fps | 97.3% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 39,204 psi | 60% | 3074 fps | 96.6% |
| ReloadSwiss RS 76 | <<locked>> | 96% | 42,989 psi | 66% | 3182 fps | 96.2% |
| Rottweil R 902 | <<locked>> | 80% | 53,548 psi | 82% | 3255 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 47,369 psi | 73% | 3173 fps | 99.9% |
| Rottweil R 904 | <<locked>> | 92% | 53,171 psi | 82% | 3264 fps | 95.6% |
| Rottweil R 905 | <<locked>> | 90% | 47,050 psi | 72% | 3196 fps | 95.4% |
| Rottweil R 907 | <<locked>> | 80% | 43,903 psi | 68% | 3077 fps | 95.3% |
| Shooters World Long Rifle | <<locked>> | 80% | 42,931 psi | 66% | 3058 fps | 97% |
| Shooters World Precision | <<locked>> | 80% | 51,706 psi | 80% | 3235 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 41,162 psi | 63% | 3031 fps | 95.3% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 48,849 psi | 75% | 3225 fps | 99.8% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 48,037 psi | 74% | 3077 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 42,221 psi | 65% | 2992 fps | 95.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 46,644 psi | 72% | 3186 fps | 95.2% |
| Somchem S355 | <<locked>> | 80% | 47,543 psi | 73% | 3173 fps | 99.8% |
| Somchem S365 | <<locked>> | 80% | 36,608 psi | 56% | 2999 fps | 99.2% |
| Somchem S385 | <<locked>> | 88% | 44,802 psi | 69% | 3107 fps | 95.7% |
| Vihtavuori N135 | <<locked>> | 80% | 53,824 psi | 83% | 3215 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 54,172 psi | 83% | 3222 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 45,469 psi | 70% | 3091 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 41,437 psi | 64% | 3051 fps | 97.7% |
| Vihtavuori N165 | <<locked>> | 92% | 44,396 psi | 68% | 3081 fps | 95.2% |
| Vihtavuori N540 | <<locked>> | 80% | 52,765 psi | 81% | 3209 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 41,075 psi | 63% | 3048 fps | 97.5% |
| Vihtavuori N555 | <<locked>> | 82% | 34,389 psi | 53% | 2927 fps | 96.1% |
| Vihtavuori N560 | <<locked>> | 94% | 52,866 psi | 81% | 3346 fps | 95% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 41,017 psi | 63% | 3012 fps | 99.5% |
| Winchester 760 | 80.8 gr | 80% | 42,554 psi | 65% | 3110 fps | 95.5% |
| Winchester StaBALL HD | <<locked>> | 84% | 29,515 psi | 45% | 2867 fps | 96.3% |
| Winchester Supreme 780 | <<locked>> | 92% | 47,921 psi | 74% | 3156 fps | 95.6% |
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 92 powders for .300 Rem. Ultra Mag. loaded with the .308 | 115gr | Sierra VarmintKing. Winchester StaBALL HD delivers the highest muzzle velocity at 3,468 fps; across all powders the maximum-charge window runs from 2,251 fps to 3,468 fps. ADI AR 2217 gives the best case fill at 100 %, and 92 of the 92 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. The 115.0 gr projectile in 0.308" calls for a 1:14.5 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Alliant Reloder-23 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. Alliant Reloder-26, Alliant Reloder-16, Winchester 760 rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 115gr | Sierra VarmintKing they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, ADI AR 2217, ADI AR 2225, Baschieri & Pellagri 109 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.