Load Specifications
Load data in caliber .300 Weath. Mag. with .306 | 160gr | AERO SB,- smax:17.9 bullet and 97 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 70, Alliant Reloder-26 and Hodgdon Superformance.
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 2495 | <<locked>> | 84% | 57,595 psi | 90% | 2956 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 55,796 psi | 87% | 2982 fps | 98.5% |
| Accurate 3100ᴾ | <<locked>> | 100% | 53,606 psi | 84% | 3018 fps | 99.4% |
| Accurate 4064 | <<locked>> | 84% | 54,433 psi | 85% | 2963 fps | 100% |
| Accurate 4350 | <<locked>> | 92% | 55,738 psi | 87% | 3077 fps | 100% |
| ADI AR 2206H | <<locked>> | 82% | 57,348 psi | 90% | 3051 fps | 100% |
| ADI AR 2208 | <<locked>> | 86% | 55,187 psi | 86% | 3005 fps | 100% |
| ADI AR 2209 | <<locked>> | 98% | 57,159 psi | 90% | 3127 fps | 98.1% |
| ADI AR 2213ᴾ | <<locked>> | 100% | 54,795 psi | 86% | 3114 fps | 96.4% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 54,505 psi | 85% | 3127 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 57,116 psi | 90% | 3120 fps | 98.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 86% | 55,898 psi | 88% | 3028 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 84% | 56,086 psi | 88% | 3048 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 94% | 56,608 psi | 89% | 3136 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 88% | 54,404 psi | 85% | 3107 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 98% | 56,304 psi | 88% | 3110 fps | 98% |
| Alliant Reloder-22ᴾ | <<locked>> | 100% | 53,635 psi | 84% | 3107 fps | 97.7% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 50,546 psi | 79% | 3038 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 43,874 psi | 69% | 2949 fps | 98.6% |
| Alliant Reloder-26 | <<locked>> | 98% | 54,360 psi | 85% | 3182 fps | 100% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 57,653 psi | 90% | 3071 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 48,907 psi | 77% | 3018 fps | 96.5% |
| Bofors RP3 | <<locked>> | 86% | 56,782 psi | 89% | 3045 fps | 100% |
| Bofors RP5ᴾ | <<locked>> | 100% | 53,635 psi | 84% | 3107 fps | 97.7% |
| Bofors RP7 | <<locked>> | 90% | 56,173 psi | 88% | 3028 fps | 98.7% |
| Hodgdon H380 | <<locked>> | 86% | 57,159 psi | 90% | 3061 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 54,462 psi | 85% | 3074 fps | 98.9% |
| Hodgdon H4350 | <<locked>> | 88% | 54,317 psi | 85% | 3031 fps | 97.9% |
| Hodgdon H4831 SCᴾ | <<locked>> | 100% | 57,624 psi | 90% | 3100 fps | 96.3% |
| Hodgdon Hybrid 100V | <<locked>> | 96% | 56,985 psi | 89% | 3058 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 54,766 psi | 86% | 3041 fps | 100% |
| Hodgdon Superformance | <<locked>> | 90% | 54,723 psi | 86% | 3110 fps | 98.8% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,303 psi | 57% | 1906 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 55,564 psi | 87% | 3009 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 54,491 psi | 85% | 2986 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 84% | 57,363 psi | 90% | 3025 fps | 99.2% |
| IMR 4350 | <<locked>> | 94% | 57,276 psi | 90% | 3061 fps | 98.9% |
| IMR 4451 Enduron | <<locked>> | 88% | 54,520 psi | 85% | 3002 fps | 98.8% |
| IMR 4831 | <<locked>> | 94% | 56,202 psi | 88% | 3068 fps | 100% |
| IMR 4895 | <<locked>> | 84% | 57,537 psi | 90% | 3077 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 98% | 56,478 psi | 89% | 3045 fps | 96.3% |
| Lovex S060 | <<locked>> | 82% | 56,043 psi | 88% | 2972 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 54,679 psi | 86% | 2979 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 54,259 psi | 85% | 2992 fps | 99.5% |
| Lovex S070 | <<locked>> | 92% | 55,666 psi | 87% | 3038 fps | 99.1% |
| Lovex S071ᴾ | <<locked>> | 100% | 44,353 psi | 70% | 2854 fps | 97.9% |
| Norma 201 | <<locked>> | 82% | 55,869 psi | 88% | 2989 fps | 100% |
| Norma 202 | <<locked>> | 82% | 56,623 psi | 89% | 2986 fps | 100% |
| Norma 203B | <<locked>> | 84% | 55,332 psi | 87% | 3035 fps | 100% |
| Norma 204 | <<locked>> | 92% | 54,520 psi | 85% | 3054 fps | 97.5% |
| Norma MRPᴾ | <<locked>> | 100% | 57,203 psi | 90% | 3199 fps | 99.3% |
| Norma URP | <<locked>> | 92% | 54,505 psi | 85% | 3061 fps | 99.9% |
| Ramshot Big Game | <<locked>> | 84% | 56,405 psi | 88% | 3061 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 52,446 psi | 82% | 3094 fps | 96.3% |
| Ramshot Hunter | <<locked>> | 94% | 57,232 psi | 90% | 3120 fps | 99.7% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 46,601 psi | 73% | 2956 fps | 96.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,883 psi | 58% | 1949 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 57,232 psi | 90% | 3045 fps | 99.5% |
| ReloadSwiss RS 52 | <<locked>> | 82% | 57,174 psi | 90% | 3123 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 86% | 53,809 psi | 84% | 3100 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 92% | 55,738 psi | 87% | 3097 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 54,389 psi | 85% | 3130 fps | 99.9% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 42,902 psi | 67% | 2963 fps | 96.6% |
| Rottweil R 902 | <<locked>> | 84% | 56,536 psi | 89% | 2992 fps | 100% |
| Rottweil R 903 | <<locked>> | 88% | 56,652 psi | 89% | 3035 fps | 100% |
| Rottweil R 904 | <<locked>> | 96% | 55,027 psi | 86% | 3031 fps | 96.6% |
| Rottweil R 905 | <<locked>> | 98% | 55,448 psi | 87% | 3091 fps | 98% |
| Rottweil R 907 | <<locked>> | 90% | 56,173 psi | 88% | 3028 fps | 98.7% |
| Shooters World Long Rifle | <<locked>> | 90% | 54,259 psi | 85% | 2992 fps | 99.5% |
| Shooters World Precision | <<locked>> | 84% | 54,679 psi | 86% | 2979 fps | 100% |
| Shooters World SW4350 | <<locked>> | 92% | 55,666 psi | 87% | 3038 fps | 99.1% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 55,071 psi | 86% | 3048 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 55,767 psi | 87% | 3018 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 56,666 psi | 89% | 2920 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 54,433 psi | 85% | 2874 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 54,114 psi | 85% | 2946 fps | 98.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 54,969 psi | 86% | 3087 fps | 97.9% |
| Somchem S335 | <<locked>> | 82% | 56,449 psi | 88% | 2917 fps | 100% |
| Somchem S355 | <<locked>> | 88% | 56,739 psi | 89% | 3035 fps | 100% |
| Somchem S361 | <<locked>> | 96% | 56,942 psi | 89% | 3025 fps | 96.2% |
| Somchem S365 | <<locked>> | 96% | 57,740 psi | 90% | 3120 fps | 100% |
| Somchem S385 | <<locked>> | 98% | 56,173 psi | 88% | 3068 fps | 98.7% |
| Vihtavuori N133 | <<locked>> | 82% | 57,232 psi | 90% | 2900 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 57,087 psi | 89% | 2949 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 57,450 psi | 90% | 2966 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 54,447 psi | 85% | 2956 fps | 100% |
| Vihtavuori N160 | <<locked>> | 92% | 56,739 psi | 89% | 3058 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 51,837 psi | 81% | 2979 fps | 97.7% |
| Vihtavuori N540 | <<locked>> | 84% | 55,637 psi | 87% | 2963 fps | 100% |
| Vihtavuori N550 | <<locked>> | 92% | 55,767 psi | 87% | 3061 fps | 99.9% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 56,347 psi | 88% | 3117 fps | 100% |
| Vihtavuori N560ᴾ | <<locked>> | 100% | 57,450 psi | 90% | 3189 fps | 96.7% |
| Winchester 6.5 StaBALL | <<locked>> | 92% | 56,637 psi | 89% | 3022 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 54,679 psi | 86% | 3077 fps | 98.9% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 45,571 psi | 71% | 3091 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 82% | 56,130 psi | 88% | 3028 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 56,478 psi | 89% | 3061 fps | 97.9% |
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 2495 | <<locked>> | 80% | 50,473 psi | 79% | 2854 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 48,849 psi | 77% | 2861 fps | 97.2% |
| Accurate 3100 | <<locked>> | 88% | 35,114 psi | 55% | 2651 fps | 95.1% |
| Accurate 4064 | <<locked>> | 80% | 47,877 psi | 75% | 2861 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 36,419 psi | 57% | 2703 fps | 97.3% |
| ADI AR 2206H | <<locked>> | 80% | 53,766 psi | 84% | 2995 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 45,614 psi | 71% | 2838 fps | 99.5% |
| ADI AR 2209 | <<locked>> | 92% | 46,659 psi | 73% | 2933 fps | 95.8% |
| ADI AR 2213 | <<locked>> | 98% | 51,184 psi | 80% | 3048 fps | 95.5% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 50,705 psi | 79% | 3064 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 90% | 43,772 psi | 69% | 2871 fps | 95% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 46,108 psi | 72% | 2861 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 49,240 psi | 77% | 2936 fps | 99.9% |
| Alliant Reloder-16 | <<locked>> | 80% | 35,708 psi | 56% | 2717 fps | 97.4% |
| Alliant Reloder-17 | <<locked>> | 80% | 40,611 psi | 64% | 2854 fps | 99.7% |
| Alliant Reloder-19 | <<locked>> | 92% | 46,195 psi | 72% | 2923 fps | 95.8% |
| Alliant Reloder-22 | <<locked>> | 94% | 43,526 psi | 68% | 2910 fps | 95.1% |
| Alliant Reloder-23 | <<locked>> | 82% | 27,717 psi | 43% | 2503 fps | 95.5% |
| Alliant Reloder-25 | <<locked>> | 94% | 35,998 psi | 56% | 2759 fps | 96% |
| Alliant Reloder-26 | 72.2 gr | 84% | 31,937 psi | 50% | 2684 fps | 95% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 53,882 psi | 84% | 3012 fps | 100% |
| Bofors RP15 | <<locked>> | 98% | 45,876 psi | 72% | 2959 fps | 95.7% |
| Bofors RP3 | <<locked>> | 80% | 46,224 psi | 72% | 2871 fps | 100% |
| Bofors RP5 | <<locked>> | 94% | 43,526 psi | 68% | 2910 fps | 95.1% |
| Bofors RP7 | <<locked>> | 80% | 40,683 psi | 64% | 2730 fps | 95.2% |
| Hodgdon H380 | <<locked>> | 80% | 46,702 psi | 73% | 2881 fps | 99.1% |
| Hodgdon H414 | <<locked>> | 80% | 38,696 psi | 61% | 2759 fps | 95.2% |
| Hodgdon H4350 | <<locked>> | 82% | 44,483 psi | 70% | 2848 fps | 95.6% |
| Hodgdon H4831 SC | <<locked>> | 98% | 53,780 psi | 84% | 3038 fps | 95.5% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 33,199 psi | 52% | 2608 fps | 98% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 51,285 psi | 80% | 2986 fps | 100% |
| Hodgdon Superformance | 72.7 gr | 82% | 40,524 psi | 64% | 2831 fps | 95.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,050 psi | 42% | 1706 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 52,069 psi | 82% | 2953 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 47,935 psi | 75% | 2874 fps | 99.8% |
| IMR 4166 Enduron | <<locked>> | 80% | 50,299 psi | 79% | 2904 fps | 98.2% |
| IMR 4350 | <<locked>> | 84% | 41,495 psi | 65% | 2769 fps | 95.5% |
| IMR 4451 Enduron | <<locked>> | 80% | 42,177 psi | 66% | 2766 fps | 96.2% |
| IMR 4831 | <<locked>> | 80% | 35,143 psi | 55% | 2657 fps | 97% |
| IMR 4895 | <<locked>> | 80% | 50,517 psi | 79% | 2966 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 52,968 psi | 83% | 2986 fps | 95.5% |
| Lovex S060 | <<locked>> | 80% | 52,794 psi | 83% | 2920 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 48,182 psi | 76% | 2871 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 39,581 psi | 62% | 2710 fps | 97% |
| Lovex S070 | <<locked>> | 80% | 37,782 psi | 59% | 2687 fps | 95.2% |
| Lovex S071 | <<locked>> | 94% | 36,201 psi | 57% | 2677 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 52,344 psi | 82% | 2933 fps | 100% |
| Norma 202 | <<locked>> | 80% | 53,287 psi | 84% | 2936 fps | 100% |
| Norma 203B | <<locked>> | 80% | 48,573 psi | 76% | 2920 fps | 100% |
| Norma 204 | <<locked>> | 86% | 44,338 psi | 69% | 2864 fps | 95% |
| Norma MRP | <<locked>> | 90% | 39,842 psi | 62% | 2861 fps | 95.5% |
| Norma URP | <<locked>> | 80% | 36,434 psi | 57% | 2703 fps | 97.2% |
| Ramshot Big Game | <<locked>> | 80% | 49,081 psi | 77% | 2943 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 48,631 psi | 76% | 3022 fps | 95.3% |
| Ramshot Hunter | <<locked>> | 82% | 37,855 psi | 59% | 2746 fps | 95.9% |
| Ramshot Magnum | <<locked>> | 98% | 43,381 psi | 68% | 2887 fps | 95.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,470 psi | 43% | 1745 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 46,876 psi | 73% | 2864 fps | 98.1% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 53,447 psi | 84% | 3061 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 43,207 psi | 68% | 2917 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 36,390 psi | 57% | 2723 fps | 97% |
| ReloadSwiss RS 70 | 68.2 gr | 80% | 35,476 psi | 56% | 2726 fps | 96.2% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 39,914 psi | 63% | 2887 fps | 95.3% |
| Rottweil R 902 | <<locked>> | 80% | 49,821 psi | 78% | 2884 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 43,439 psi | 68% | 2812 fps | 99.8% |
| Rottweil R 904 | <<locked>> | 92% | 48,414 psi | 76% | 2913 fps | 95% |
| Rottweil R 905 | <<locked>> | 92% | 45,150 psi | 71% | 2904 fps | 95.7% |
| Rottweil R 907 | <<locked>> | 80% | 40,683 psi | 64% | 2730 fps | 95.2% |
| Shooters World Long Rifle | <<locked>> | 80% | 39,581 psi | 62% | 2710 fps | 97% |
| Shooters World Precision | <<locked>> | 80% | 48,182 psi | 76% | 2871 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 37,782 psi | 59% | 2687 fps | 95.2% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 44,860 psi | 70% | 2871 fps | 99.7% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 52,344 psi | 82% | 2963 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 53,214 psi | 83% | 2871 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 44,947 psi | 70% | 2726 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 38,682 psi | 61% | 2651 fps | 95.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 92% | 44,730 psi | 70% | 2897 fps | 95.5% |
| Somchem S335 | <<locked>> | 80% | 52,968 psi | 83% | 2867 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 43,830 psi | 69% | 2815 fps | 99.8% |
| Somchem S361 | <<locked>> | 94% | 53,214 psi | 83% | 2963 fps | 95.3% |
| Somchem S365 | <<locked>> | 80% | 32,909 psi | 52% | 2654 fps | 99.1% |
| Somchem S385 | <<locked>> | 88% | 40,103 psi | 63% | 2766 fps | 95% |
| Vihtavuori N133 | <<locked>> | 80% | 53,824 psi | 84% | 2854 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 50,082 psi | 78% | 2848 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 50,459 psi | 79% | 2864 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 41,872 psi | 66% | 2740 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 37,855 psi | 59% | 2707 fps | 97.6% |
| Vihtavuori N165 | <<locked>> | 94% | 42,250 psi | 66% | 2799 fps | 95.3% |
| Vihtavuori N540 | <<locked>> | 80% | 48,776 psi | 76% | 2854 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 37,333 psi | 59% | 2703 fps | 97.3% |
| Vihtavuori N555 | <<locked>> | 82% | 30,516 psi | 48% | 2585 fps | 95.7% |
| Vihtavuori N560 | <<locked>> | 98% | 53,490 psi | 84% | 3120 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 37,188 psi | 58% | 2677 fps | 99.3% |
| Winchester 760 | <<locked>> | 80% | 38,696 psi | 61% | 2759 fps | 95.2% |
| Winchester StaBALL HD | <<locked>> | 84% | 26,107 psi | 41% | 2523 fps | 95% |
| Winchester StaBALL Match | <<locked>> | 80% | 52,417 psi | 82% | 2969 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 94% | 45,571 psi | 71% | 2871 fps | 95.5% |
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 97 powders for .300 Weath. Mag. loaded with the .306 | 160gr | AERO SB,- smax:17.9. Norma MRP delivers the highest muzzle velocity at 3,199 fps; across all powders the maximum-charge window runs from 1,906 fps to 3,199 fps. Accurate 3100 gives the best case fill at 100 %, and 97 of the 97 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (440 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 160.0 gr projectile in 0.306" calls for a 1:11.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2213, Alliant Reloder-22 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. ReloadSwiss RS 70, Alliant Reloder-26, Hodgdon Superformance rank at the top here: for .300 Weath. Mag. with the .306 | 160gr | AERO SB,- smax:17.9 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.