Load Specifications
Bullet Manufacturer:Sierra
Bullet Weight:177 gr
Bullet Diameter:0.308"
Bullet Length:<<locked>>
Caliber:.300 Weath. Mag. load data
Case Length (l3):2.824"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:98.9 Grains of Water
Primer Size:Large Rifle Magnum (LRM)
Barrel Length:24"
Max. allowed Pressure:63,817 psi
Recommended Twist Rate:1:12.5
Load data in caliber .300 Weath. Mag. with .308 | 177gr | Sierra Hollow Point Boat Tail - Closed Nose bullet and 84 powders. The key underlying parameters are shown in the table above.
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% | 57,537 psi | 90% | 2884 fps | 99.4% |
| Accurate 3100 | <<locked>> | 98% | 57,348 psi | 90% | 2943 fps | 100% |
| Accurate 4064 | <<locked>> | 82% | 57,566 psi | 90% | 2864 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 55,274 psi | 87% | 2930 fps | 100% |
| Accurate High Country | <<locked>> | 94% | 54,897 psi | 86% | 3031 fps | 98% |
| Accurate MAGPRO | <<locked>> | 96% | 55,840 psi | 88% | 3035 fps | 97% |
| ADI AR 2208 | <<locked>> | 84% | 57,072 psi | 89% | 2897 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 55,941 psi | 88% | 2979 fps | 98.8% |
| ADI AR 2213 | <<locked>> | 98% | 57,566 psi | 90% | 3041 fps | 98.2% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 39,827 psi | 62% | 2753 fps | 97.3% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 56,318 psi | 88% | 2979 fps | 98.9% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 54,766 psi | 86% | 2871 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 55,970 psi | 88% | 2986 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 57,421 psi | 90% | 3005 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 55,579 psi | 87% | 2966 fps | 98.8% |
| Alliant Reloder-22 | <<locked>> | 98% | 57,145 psi | 90% | 3035 fps | 99.1% |
| Alliant Reloder-23 | <<locked>> | 98% | 54,273 psi | 85% | 2953 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 50,096 psi | 79% | 2949 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 94% | 54,491 psi | 85% | 3041 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 55,811 psi | 87% | 3009 fps | 98.9% |
| Bofors RP3 | <<locked>> | 82% | 55,680 psi | 87% | 2887 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 45,934 psi | 72% | 2867 fps | 96.4% |
| Bofors RP5 | <<locked>> | 98% | 57,145 psi | 90% | 3035 fps | 99.1% |
| Bofors RP7 | <<locked>> | 86% | 54,766 psi | 86% | 2877 fps | 99.3% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 49,385 psi | 77% | 2890 fps | 97.4% |
| Hodgdon H380 | <<locked>> | 82% | 55,753 psi | 87% | 2904 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 57,246 psi | 90% | 2986 fps | 99.8% |
| Hodgdon H4350 | <<locked>> | 86% | 56,318 psi | 88% | 2940 fps | 99.1% |
| Hodgdon H4831 | <<locked>> | 96% | 57,508 psi | 90% | 2976 fps | 97.6% |
| Hodgdon H4831 SC | <<locked>> | 96% | 56,347 psi | 88% | 2956 fps | 97.3% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 56,347 psi | 88% | 2910 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 49,095 psi | 77% | 2999 fps | 98.7% |
| Hodgdon Superformance | <<locked>> | 86% | 53,722 psi | 84% | 2959 fps | 99.4% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,796 psi | 58% | 1827 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 56,420 psi | 88% | 2877 fps | 100% |
| IMR 4350 | <<locked>> | 90% | 55,985 psi | 88% | 2913 fps | 99.4% |
| IMR 4451 Enduron | <<locked>> | 86% | 56,159 psi | 88% | 2900 fps | 99.6% |
| IMR 4831 | <<locked>> | 90% | 55,521 psi | 87% | 2920 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 55,085 psi | 86% | 2904 fps | 97.3% |
| IMR 7828 SSC | <<locked>> | 98% | 54,897 psi | 86% | 3009 fps | 97.8% |
| Lovex S062 | <<locked>> | 82% | 56,724 psi | 89% | 2867 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 56,782 psi | 89% | 2900 fps | 100% |
| Lovex S070 | <<locked>> | 88% | 54,665 psi | 86% | 2890 fps | 99.6% |
| Lovex S071ᴾ | <<locked>> | 100% | 51,010 psi | 80% | 2848 fps | 99.6% |
| Norma 203B | <<locked>> | 82% | 57,493 psi | 90% | 2927 fps | 100% |
| Norma 204 | <<locked>> | 90% | 56,985 psi | 89% | 2969 fps | 98.8% |
| Norma MRP | <<locked>> | 96% | 56,956 psi | 89% | 3061 fps | 99.8% |
| Norma URP | <<locked>> | 90% | 57,319 psi | 90% | 2966 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 55,767 psi | 87% | 3031 fps | 98.3% |
| Ramshot Hunter | <<locked>> | 90% | 56,217 psi | 88% | 2969 fps | 99.9% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 53,766 psi | 84% | 2963 fps | 99.2% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,507 psi | 59% | 1870 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 55,419 psi | 87% | 2887 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 56,826 psi | 89% | 2995 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 55,172 psi | 86% | 2953 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 57,406 psi | 90% | 3038 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 49,414 psi | 77% | 2995 fps | 99.5% |
| Rottweil R 903 | <<locked>> | 84% | 55,753 psi | 87% | 2884 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 57,551 psi | 90% | 2949 fps | 98.2% |
| Rottweil R 905 | <<locked>> | 94% | 54,926 psi | 86% | 2956 fps | 98.8% |
| Rottweil R 907 | <<locked>> | 86% | 54,766 psi | 86% | 2877 fps | 99.3% |
| Shooters World Long Rifle | <<locked>> | 88% | 56,782 psi | 89% | 2900 fps | 100% |
| Shooters World Precision | <<locked>> | 82% | 56,724 psi | 89% | 2867 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 54,665 psi | 86% | 2890 fps | 99.6% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 57,377 psi | 90% | 2943 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 56,173 psi | 88% | 2762 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 56,188 psi | 88% | 2854 fps | 99.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 94% | 54,476 psi | 85% | 2949 fps | 98.8% |
| Somchem S355 | <<locked>> | 84% | 55,608 psi | 87% | 2877 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 55,550 psi | 87% | 2884 fps | 97.2% |
| Somchem S365 | <<locked>> | 92% | 57,363 psi | 90% | 2966 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 55,492 psi | 87% | 2930 fps | 99.3% |
| Vihtavuori N150 | <<locked>> | 86% | 56,811 psi | 89% | 2851 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 55,724 psi | 87% | 2907 fps | 100% |
| Vihtavuori N165 | <<locked>> | 98% | 54,926 psi | 86% | 2907 fps | 99.1% |
| Vihtavuori N540 | <<locked>> | 82% | 57,508 psi | 90% | 2848 fps | 100% |
| Vihtavuori N550 | <<locked>> | 88% | 54,969 psi | 86% | 2913 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 56,739 psi | 89% | 2982 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 56,898 psi | 89% | 3048 fps | 97.8% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 52,446 psi | 82% | 2959 fps | 97.2% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 55,187 psi | 86% | 2867 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 57,246 psi | 90% | 2986 fps | 99.8% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 54,810 psi | 86% | 3087 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 55,593 psi | 87% | 2923 fps | 98.7% |
Start Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2700 | <<locked>> | 80% | 53,882 psi | 84% | 2828 fps | 99% |
| Accurate 3100 | <<locked>> | 82% | 33,301 psi | 52% | 2490 fps | 95.8% |
| Accurate 4064 | <<locked>> | 80% | 54,041 psi | 85% | 2812 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 42,032 psi | 66% | 2700 fps | 99.4% |
| Accurate High Country | <<locked>> | 88% | 44,469 psi | 70% | 2838 fps | 95.5% |
| Accurate MAGPRO | <<locked>> | 92% | 48,341 psi | 76% | 2900 fps | 95.2% |
| ADI AR 2208 | <<locked>> | 80% | 50,343 psi | 79% | 2792 fps | 100% |
| ADI AR 2209 | <<locked>> | 84% | 40,335 psi | 63% | 2680 fps | 95.2% |
| ADI AR 2213 | <<locked>> | 92% | 47,036 psi | 74% | 2851 fps | 95.9% |
| ADI AR 2225 | <<locked>> | 96% | 35,012 psi | 55% | 2625 fps | 95.1% |
| Alliant Power Pro Varmint | <<locked>> | 84% | 40,625 psi | 64% | 2684 fps | 95.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 51,401 psi | 81% | 2818 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 40,379 psi | 63% | 2707 fps | 99.5% |
| Alliant Reloder-17 | <<locked>> | 80% | 46,427 psi | 73% | 2831 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 40,219 psi | 63% | 2677 fps | 95.3% |
| Alliant Reloder-22 | <<locked>> | 88% | 40,785 psi | 64% | 2730 fps | 95.7% |
| Alliant Reloder-23 | <<locked>> | 80% | 29,936 psi | 47% | 2464 fps | 98.1% |
| Alliant Reloder-25 | <<locked>> | 86% | 31,836 psi | 50% | 2533 fps | 95.7% |
| Alliant Reloder-26 | <<locked>> | 80% | 32,329 psi | 51% | 2585 fps | 96.8% |
| Bofors RP15 | <<locked>> | 90% | 40,263 psi | 63% | 2717 fps | 95.3% |
| Bofors RP3 | <<locked>> | 80% | 52,025 psi | 82% | 2831 fps | 100% |
| Bofors RP30 | <<locked>> | 98% | 42,975 psi | 67% | 2808 fps | 95.5% |
| Bofors RP5 | <<locked>> | 88% | 40,785 psi | 64% | 2730 fps | 95.7% |
| Bofors RP7 | <<locked>> | 80% | 45,295 psi | 71% | 2710 fps | 97.8% |
| Hodgdon H1000 | <<locked>> | 96% | 43,033 psi | 67% | 2762 fps | 95.5% |
| Hodgdon H380 | <<locked>> | 80% | 52,127 psi | 82% | 2848 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 43,772 psi | 69% | 2746 fps | 98% |
| Hodgdon H4350 | <<locked>> | 80% | 46,499 psi | 73% | 2766 fps | 97.4% |
| Hodgdon H4831 | <<locked>> | 90% | 46,978 psi | 74% | 2795 fps | 95.2% |
| Hodgdon H4831 SC | <<locked>> | 92% | 49,356 psi | 77% | 2841 fps | 95.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 38,087 psi | 60% | 2598 fps | 99.7% |
| Hodgdon Retumbo | <<locked>> | 94% | 40,277 psi | 63% | 2802 fps | 96.1% |
| Hodgdon Superformance | <<locked>> | 80% | 42,960 psi | 67% | 2766 fps | 97.5% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,470 psi | 43% | 1631 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 52,982 psi | 83% | 2825 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 40,959 psi | 64% | 2638 fps | 96.7% |
| IMR 4451 Enduron | <<locked>> | 80% | 46,630 psi | 73% | 2736 fps | 98.4% |
| IMR 4831 | <<locked>> | 80% | 40,176 psi | 63% | 2651 fps | 99.2% |
| IMR 4955 Enduron | <<locked>> | 88% | 45,687 psi | 72% | 2736 fps | 95% |
| IMR 7828 SSC | <<locked>> | 92% | 45,034 psi | 71% | 2825 fps | 95.4% |
| Lovex S062 | <<locked>> | 80% | 53,505 psi | 84% | 2822 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 44,280 psi | 69% | 2687 fps | 99% |
| Lovex S070 | <<locked>> | 80% | 42,554 psi | 67% | 2674 fps | 97.9% |
| Lovex S071 | <<locked>> | 86% | 32,590 psi | 51% | 2470 fps | 95.5% |
| Norma 203B | <<locked>> | 80% | 54,027 psi | 85% | 2874 fps | 100% |
| Norma 204 | <<locked>> | 80% | 40,553 psi | 64% | 2664 fps | 95.2% |
| Norma MRP | <<locked>> | 84% | 37,231 psi | 58% | 2677 fps | 95.9% |
| Norma URP | <<locked>> | 80% | 41,437 psi | 65% | 2690 fps | 99.3% |
| Ramshot Grand | <<locked>> | 92% | 44,773 psi | 70% | 2831 fps | 95.7% |
| Ramshot Hunter | <<locked>> | 80% | 40,219 psi | 63% | 2677 fps | 97.9% |
| Ramshot Magnum | <<locked>> | 90% | 37,275 psi | 58% | 2644 fps | 95.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,166 psi | 44% | 1673 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 51,938 psi | 81% | 2831 fps | 99.5% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 49,240 psi | 77% | 2881 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 41,814 psi | 66% | 2717 fps | 99.2% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 40,190 psi | 63% | 2726 fps | 98.9% |
| ReloadSwiss RS 76 | <<locked>> | 92% | 37,072 psi | 58% | 2713 fps | 96% |
| Rottweil R 903 | <<locked>> | 80% | 48,994 psi | 77% | 2779 fps | 100% |
| Rottweil R 904 | <<locked>> | 86% | 44,570 psi | 70% | 2720 fps | 95.4% |
| Rottweil R 905 | <<locked>> | 84% | 39,320 psi | 62% | 2657 fps | 95.2% |
| Rottweil R 907 | <<locked>> | 80% | 45,295 psi | 71% | 2710 fps | 97.8% |
| Shooters World Long Rifle | <<locked>> | 80% | 44,280 psi | 69% | 2687 fps | 99% |
| Shooters World Precision | <<locked>> | 80% | 53,505 psi | 84% | 2822 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 42,554 psi | 67% | 2674 fps | 97.9% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 50,227 psi | 79% | 2831 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 49,603 psi | 78% | 2667 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 43,395 psi | 68% | 2635 fps | 97.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 38,957 psi | 61% | 2654 fps | 95.1% |
| Somchem S355 | <<locked>> | 80% | 49,008 psi | 77% | 2772 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 48,762 psi | 76% | 2769 fps | 95.7% |
| Somchem S365 | <<locked>> | 80% | 38,218 psi | 60% | 2648 fps | 100% |
| Somchem S385 | <<locked>> | 82% | 37,521 psi | 59% | 2589 fps | 95.5% |
| Vihtavuori N150 | <<locked>> | 80% | 46,891 psi | 73% | 2700 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 42,859 psi | 67% | 2687 fps | 99.5% |
| Vihtavuori N165 | <<locked>> | 88% | 39,479 psi | 62% | 2625 fps | 95.8% |
| Vihtavuori N540 | <<locked>> | 80% | 53,882 psi | 84% | 2799 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 42,250 psi | 66% | 2690 fps | 99.3% |
| Vihtavuori N555 | <<locked>> | 80% | 33,547 psi | 53% | 2543 fps | 98.1% |
| Vihtavuori N560 | <<locked>> | 90% | 46,238 psi | 72% | 2858 fps | 95.3% |
| Vihtavuori N565 | <<locked>> | 96% | 45,803 psi | 72% | 2835 fps | 95.5% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 41,989 psi | 66% | 2654 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 43,961 psi | 69% | 2753 fps | 98% |
| Winchester StaBALL HD | <<locked>> | 80% | 26,484 psi | 42% | 2448 fps | 97.5% |
| Winchester Supreme 780 | <<locked>> | 86% | 39,305 psi | 62% | 2625 fps | 95% |
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 84 powders for .300 Weath. Mag. loaded with the .308 | 177gr | Sierra Hollow Point Boat Tail - Closed Nose . Winchester StaBALL HD delivers the highest muzzle velocity at 3,087 fps; across all powders the maximum-charge window runs from 1,827 fps to 3,087 fps. ADI AR 2225 gives the best case fill at 100 %, and 84 of the 84 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 58–90 %, leaving at least 10 % headroom. The 177.0 gr projectile in 0.308" calls for a 1:12.5 twist; slower twists will usually not stabilise this weight. ADI AR 2225, Alliant Reloder-25, Bofors RP15 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. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.