Load Specifications
Load data in caliber .300 H&H Mag. with .307 | 150gr | Rhino Solid Shank bullet and 97 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Reloder-16, ReloadSwiss RS 70 and Ramshot Hunter.
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>> | 86% | 56,347 psi | 90% | 2986 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 54,563 psi | 87% | 2986 fps | 97% |
| Accurate 3100ᴾ | <<locked>> | 100% | 47,239 psi | 76% | 2940 fps | 97.3% |
| Accurate 4064 | <<locked>> | 88% | 56,362 psi | 90% | 3038 fps | 100% |
| Accurate 4350 | <<locked>> | 94% | 53,243 psi | 85% | 3074 fps | 99.5% |
| ADI AR 2206H | <<locked>> | 84% | 56,057 psi | 90% | 3068 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 53,635 psi | 86% | 3012 fps | 99.7% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 54,621 psi | 88% | 3104 fps | 96.1% |
| ADI Benchmark 8208 | <<locked>> | 82% | 54,737 psi | 88% | 3012 fps | 100% |
| Alliant AR-Comp | <<locked>> | 82% | 56,101 psi | 90% | 2989 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 86% | 56,144 psi | 90% | 3196 fps | 99.9% |
| Alliant Power Pro Varmintᴾ | <<locked>> | 100% | 54,433 psi | 87% | 3100 fps | 96.2% |
| Alliant Reloder- TS 15.5 | <<locked>> | 88% | 54,143 psi | 87% | 3038 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 86% | 54,302 psi | 87% | 3058 fps | 99.8% |
| Alliant Reloder-16 | <<locked>> | 96% | 54,085 psi | 87% | 3133 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 92% | 55,317 psi | 89% | 3166 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 53,650 psi | 86% | 3091 fps | 96.1% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 44,498 psi | 71% | 2966 fps | 99.6% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 50,560 psi | 81% | 3153 fps | 99.2% |
| Baschieri & Pellagri 107 | <<locked>> | 84% | 55,970 psi | 90% | 3081 fps | 99.7% |
| Bofors RP3 | <<locked>> | 88% | 54,708 psi | 88% | 3051 fps | 100% |
| Bofors RP7 | <<locked>> | 92% | 54,505 psi | 87% | 3022 fps | 97.2% |
| Hodgdon Benchmark | <<locked>> | 82% | 56,217 psi | 90% | 2995 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 82% | 54,404 psi | 87% | 3038 fps | 100% |
| Hodgdon H380 | <<locked>> | 88% | 55,376 psi | 89% | 3064 fps | 99.4% |
| Hodgdon H414 | <<locked>> | 94% | 55,753 psi | 89% | 3127 fps | 98.1% |
| Hodgdon H4350 | <<locked>> | 92% | 55,782 psi | 89% | 3084 fps | 96.8% |
| Hodgdon H4895 | <<locked>> | 82% | 53,113 psi | 85% | 3022 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 98% | 53,983 psi | 87% | 3054 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 52,808 psi | 85% | 3054 fps | 100% |
| Hodgdon Superformance | <<locked>> | 94% | 56,159 psi | 90% | 3163 fps | 97.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,897 psi | 58% | 1913 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 54,244 psi | 87% | 3025 fps | 100% |
| IMR 3031 | <<locked>> | 82% | 53,258 psi | 85% | 3005 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 53,200 psi | 85% | 2995 fps | 99.8% |
| IMR 4166 Enduron | <<locked>> | 86% | 56,188 psi | 90% | 3028 fps | 98% |
| IMR 4350 | <<locked>> | 96% | 55,085 psi | 88% | 3051 fps | 97.4% |
| IMR 4451 Enduron | <<locked>> | 92% | 56,405 psi | 90% | 3058 fps | 98% |
| IMR 4831 | <<locked>> | 96% | 53,693 psi | 86% | 3064 fps | 99.6% |
| IMR 4895 | <<locked>> | 86% | 55,738 psi | 89% | 3091 fps | 100% |
| IMR 8208 XBR | <<locked>> | 82% | 54,737 psi | 88% | 3012 fps | 100% |
| Lovex D073.6 | <<locked>> | 84% | 56,289 psi | 90% | 3041 fps | 100% |
| Lovex S060 | <<locked>> | 84% | 55,114 psi | 88% | 2989 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 53,156 psi | 85% | 2992 fps | 100% |
| Lovex S065 | <<locked>> | 94% | 55,912 psi | 90% | 3048 fps | 99% |
| Lovex S070 | <<locked>> | 94% | 53,737 psi | 86% | 3031 fps | 97.8% |
| Norma 201 | <<locked>> | 84% | 54,621 psi | 88% | 3009 fps | 100% |
| Norma 202 | <<locked>> | 84% | 55,419 psi | 89% | 3012 fps | 100% |
| Norma 203B | <<locked>> | 86% | 53,592 psi | 86% | 3041 fps | 99.9% |
| Norma 204 | <<locked>> | 96% | 55,796 psi | 89% | 3100 fps | 96.3% |
| Norma MRPᴾ | <<locked>> | 100% | 49,966 psi | 80% | 3104 fps | 96.9% |
| Norma URP | <<locked>> | 96% | 55,695 psi | 89% | 3117 fps | 99.6% |
| Ramshot Big Game | <<locked>> | 86% | 54,360 psi | 87% | 3071 fps | 99.9% |
| Ramshot Hunter | <<locked>> | 96% | 54,288 psi | 87% | 3107 fps | 98.6% |
| Ramshot TAC | <<locked>> | 82% | 54,853 psi | 88% | 3028 fps | 99% |
| Ramshot Wild Boar | <<locked>> | 82% | 54,708 psi | 88% | 3048 fps | 99.9% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,492 psi | 59% | 1955 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 88% | 55,477 psi | 89% | 3045 fps | 98.4% |
| ReloadSwiss RS 52 | <<locked>> | 84% | 55,100 psi | 88% | 3130 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 90% | 54,781 psi | 88% | 3163 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 52,953 psi | 85% | 3094 fps | 99.3% |
| ReloadSwiss RS 70 | <<locked>> | 96% | 55,738 psi | 89% | 3182 fps | 99.5% |
| Rottweil R 901 | <<locked>> | 82% | 55,637 psi | 89% | 2992 fps | 100% |
| Rottweil R 902 | <<locked>> | 86% | 55,405 psi | 89% | 3009 fps | 100% |
| Rottweil R 903 | <<locked>> | 90% | 54,795 psi | 88% | 3048 fps | 100% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 52,504 psi | 84% | 3068 fps | 96% |
| Rottweil R 907 | <<locked>> | 92% | 54,505 psi | 87% | 3022 fps | 97.2% |
| Shooters World Long Rifle | <<locked>> | 94% | 55,912 psi | 90% | 3048 fps | 99% |
| Shooters World Match Rifle | <<locked>> | 84% | 56,289 psi | 90% | 3041 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 53,156 psi | 85% | 2992 fps | 100% |
| Shooters World SW4350 | <<locked>> | 94% | 53,737 psi | 86% | 3031 fps | 97.8% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 52,779 psi | 85% | 3051 fps | 99.9% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 53,563 psi | 86% | 3005 fps | 99.1% |
| SNPE Vectan SP 9 | <<locked>> | 84% | 54,447 psi | 87% | 3031 fps | 99.9% |
| SNPE Vectan Tubal 3000 | <<locked>> | 84% | 55,782 psi | 89% | 2946 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 53,098 psi | 85% | 2894 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 94% | 56,115 psi | 90% | 3002 fps | 98% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 52,011 psi | 83% | 3061 fps | 95.8% |
| Somchem S335 | <<locked>> | 84% | 55,303 psi | 89% | 2940 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 53,258 psi | 85% | 2995 fps | 99.9% |
| Somchem S355 | <<locked>> | 90% | 54,998 psi | 88% | 3045 fps | 100% |
| Somchem S365 | <<locked>> | 98% | 54,143 psi | 87% | 3117 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 53,388 psi | 86% | 3051 fps | 97% |
| Vihtavuori N133 | <<locked>> | 84% | 56,173 psi | 90% | 2927 fps | 100% |
| Vihtavuori N135 | <<locked>> | 86% | 55,332 psi | 89% | 2972 fps | 100% |
| Vihtavuori N140 | <<locked>> | 86% | 55,985 psi | 90% | 2989 fps | 100% |
| Vihtavuori N150 | <<locked>> | 92% | 56,231 psi | 90% | 3018 fps | 100% |
| Vihtavuori N160 | <<locked>> | 94% | 54,447 psi | 87% | 3058 fps | 99.5% |
| Vihtavuori N530 | <<locked>> | 82% | 55,071 psi | 88% | 3009 fps | 100% |
| Vihtavuori N540 | <<locked>> | 86% | 54,070 psi | 87% | 2979 fps | 100% |
| Vihtavuori N550 | <<locked>> | 94% | 53,563 psi | 86% | 3058 fps | 99.3% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 49,487 psi | 79% | 3048 fps | 99.5% |
| Winchester 6.5 StaBALL | <<locked>> | 94% | 54,244 psi | 87% | 3025 fps | 100% |
| Winchester 748 | <<locked>> | 82% | 55,550 psi | 89% | 3061 fps | 100% |
| Winchester 760 | <<locked>> | 94% | 55,753 psi | 89% | 3127 fps | 98.1% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 40,030 psi | 64% | 2989 fps | 99.7% |
| Winchester StaBALL Match | <<locked>> | 84% | 54,360 psi | 87% | 3038 fps | 100% |
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% | 46,209 psi | 74% | 2831 fps | 100% |
| Accurate 2700 | <<locked>> | 82% | 47,790 psi | 77% | 2861 fps | 95.5% |
| Accurate 3100 | <<locked>> | 96% | 41,031 psi | 66% | 2815 fps | 95.6% |
| Accurate 4064 | <<locked>> | 80% | 43,700 psi | 70% | 2828 fps | 100% |
| Accurate 4350 | <<locked>> | 82% | 35,012 psi | 56% | 2700 fps | 95.4% |
| ADI AR 2206H | <<locked>> | 80% | 49,284 psi | 79% | 2949 fps | 99.6% |
| ADI AR 2208 | <<locked>> | 80% | 41,901 psi | 67% | 2789 fps | 98.1% |
| ADI AR 2209 | <<locked>> | 98% | 51,111 psi | 82% | 3038 fps | 95.2% |
| ADI Benchmark 8208 | <<locked>> | 80% | 51,358 psi | 82% | 2956 fps | 100% |
| Alliant AR-Comp | <<locked>> | 80% | 52,591 psi | 84% | 2936 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 45,513 psi | 73% | 2999 fps | 98.8% |
| Alliant Power Pro Varmint | <<locked>> | 98% | 50,981 psi | 82% | 3038 fps | 95.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 41,829 psi | 67% | 2812 fps | 99.2% |
| Alliant Reloder-15 | <<locked>> | 80% | 44,875 psi | 72% | 2884 fps | 98.8% |
| Alliant Reloder-16 | 59 gr | 82% | 34,635 psi | 56% | 2710 fps | 95.4% |
| Alliant Reloder-17 | <<locked>> | 80% | 36,492 psi | 59% | 2785 fps | 97.9% |
| Alliant Reloder-19 | <<locked>> | 98% | 50,256 psi | 81% | 3028 fps | 95.2% |
| Alliant Reloder-23 | <<locked>> | 88% | 30,385 psi | 49% | 2608 fps | 95.2% |
| Alliant Reloder-26 | <<locked>> | 92% | 37,884 psi | 61% | 2874 fps | 95.9% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 48,834 psi | 78% | 2956 fps | 99% |
| Bofors RP3 | <<locked>> | 80% | 42,032 psi | 67% | 2825 fps | 99.3% |
| Bofors RP7 | <<locked>> | 86% | 45,266 psi | 73% | 2851 fps | 95% |
| Hodgdon Benchmark | <<locked>> | 80% | 52,779 psi | 85% | 2940 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 50,981 psi | 82% | 2982 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 42,511 psi | 68% | 2825 fps | 97.2% |
| Hodgdon H414 | <<locked>> | 88% | 45,527 psi | 73% | 2936 fps | 95.8% |
| Hodgdon H4350 | <<locked>> | 88% | 49,066 psi | 79% | 2963 fps | 95.3% |
| Hodgdon H4895 | <<locked>> | 80% | 49,777 psi | 80% | 2963 fps | 99.8% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 30,008 psi | 48% | 2546 fps | 95.3% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 46,064 psi | 74% | 2933 fps | 99.8% |
| Hodgdon Superformance | <<locked>> | 88% | 45,223 psi | 73% | 2956 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,731 psi | 43% | 1709 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 47,659 psi | 76% | 2910 fps | 99.7% |
| IMR 3031 | <<locked>> | 80% | 49,922 psi | 80% | 2953 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 44,048 psi | 71% | 2828 fps | 98.7% |
| IMR 4166 Enduron | <<locked>> | 80% | 46,427 psi | 74% | 2851 fps | 96% |
| IMR 4350 | <<locked>> | 90% | 45,600 psi | 73% | 2877 fps | 95.2% |
| IMR 4451 Enduron | <<locked>> | 84% | 43,947 psi | 70% | 2825 fps | 95.2% |
| IMR 4831 | <<locked>> | 82% | 33,794 psi | 54% | 2651 fps | 95% |
| IMR 4895 | <<locked>> | 80% | 45,992 psi | 74% | 2917 fps | 99.3% |
| IMR 8208 XBR | <<locked>> | 80% | 51,358 psi | 82% | 2956 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 49,095 psi | 79% | 2930 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 48,718 psi | 78% | 2881 fps | 99.6% |
| Lovex S062 | <<locked>> | 80% | 44,106 psi | 71% | 2831 fps | 99.7% |
| Lovex S065 | <<locked>> | 82% | 38,725 psi | 62% | 2713 fps | 95.2% |
| Lovex S070 | <<locked>> | 88% | 44,483 psi | 71% | 2858 fps | 95.7% |
| Norma 201 | <<locked>> | 80% | 48,211 psi | 77% | 2897 fps | 99.9% |
| Norma 202 | <<locked>> | 80% | 48,617 psi | 78% | 2904 fps | 100% |
| Norma 203B | <<locked>> | 80% | 44,237 psi | 71% | 2871 fps | 99% |
| Norma 204 | <<locked>> | 94% | 52,185 psi | 84% | 3038 fps | 95.4% |
| Norma MRP | <<locked>> | 98% | 46,717 psi | 75% | 3038 fps | 96% |
| Norma URP | <<locked>> | 82% | 35,012 psi | 56% | 2697 fps | 95.2% |
| Ramshot Big Game | <<locked>> | 80% | 44,309 psi | 71% | 2890 fps | 99% |
| Ramshot Hunter | 67.1 gr | 88% | 41,582 psi | 67% | 2861 fps | 95.6% |
| Ramshot TAC | <<locked>> | 80% | 51,343 psi | 82% | 2966 fps | 98.5% |
| Ramshot Wild Boar | <<locked>> | 80% | 51,343 psi | 82% | 2989 fps | 99.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,166 psi | 44% | 1749 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 42,801 psi | 69% | 2808 fps | 95.7% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 47,863 psi | 77% | 3002 fps | 99.2% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 38,798 psi | 62% | 2854 fps | 99.9% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 37,173 psi | 60% | 2776 fps | 95.8% |
| ReloadSwiss RS 70 | 67.7 gr | 86% | 39,363 psi | 63% | 2844 fps | 95.9% |
| Rottweil R 901 | <<locked>> | 80% | 52,417 psi | 84% | 2940 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 45,963 psi | 74% | 2848 fps | 99.8% |
| Rottweil R 903 | <<locked>> | 80% | 39,508 psi | 63% | 2762 fps | 98.7% |
| Rottweil R 905 | <<locked>> | 98% | 49,240 psi | 79% | 3009 fps | 95.1% |
| Rottweil R 907 | <<locked>> | 86% | 45,266 psi | 73% | 2851 fps | 95% |
| Shooters World Long Rifle | <<locked>> | 82% | 38,725 psi | 62% | 2713 fps | 95.2% |
| Shooters World Match Rifle | <<locked>> | 80% | 49,095 psi | 79% | 2930 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 44,106 psi | 71% | 2831 fps | 99.7% |
| Shooters World SW4350 | <<locked>> | 88% | 44,483 psi | 71% | 2858 fps | 95.7% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 40,393 psi | 65% | 2812 fps | 98.2% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 49,980 psi | 80% | 2943 fps | 98.6% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 47,703 psi | 76% | 2917 fps | 99.5% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 49,298 psi | 79% | 2844 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 41,350 psi | 66% | 2697 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 86% | 43,279 psi | 69% | 2769 fps | 95.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 98% | 48,762 psi | 78% | 3002 fps | 95% |
| Somchem S335 | <<locked>> | 80% | 48,950 psi | 78% | 2841 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 49,719 psi | 80% | 2936 fps | 99.6% |
| Somchem S355 | <<locked>> | 80% | 40,001 psi | 64% | 2762 fps | 98.6% |
| Somchem S365 | <<locked>> | 80% | 29,443 psi | 47% | 2585 fps | 96.6% |
| Somchem S385 | <<locked>> | 96% | 46,789 psi | 75% | 2930 fps | 95.5% |
| Vihtavuori N133 | <<locked>> | 80% | 49,719 psi | 80% | 2831 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 45,759 psi | 73% | 2825 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 46,253 psi | 74% | 2835 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 38,189 psi | 61% | 2697 fps | 99.2% |
| Vihtavuori N160 | <<locked>> | 82% | 36,550 psi | 59% | 2703 fps | 95.8% |
| Vihtavuori N530 | <<locked>> | 80% | 51,779 psi | 83% | 2956 fps | 100% |
| Vihtavuori N540 | <<locked>> | 80% | 44,628 psi | 72% | 2822 fps | 100% |
| Vihtavuori N550 | <<locked>> | 82% | 36,027 psi | 58% | 2700 fps | 95.4% |
| Vihtavuori N555 | <<locked>> | 88% | 33,098 psi | 53% | 2690 fps | 95.4% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 33,721 psi | 54% | 2615 fps | 97.2% |
| Winchester 748 | <<locked>> | 80% | 52,011 psi | 83% | 3005 fps | 100% |
| Winchester 760 | <<locked>> | 86% | 42,772 psi | 69% | 2877 fps | 95% |
| Winchester StaBALL HD | <<locked>> | 92% | 30,705 psi | 49% | 2700 fps | 96.1% |
| Winchester StaBALL Match | <<locked>> | 80% | 47,543 psi | 76% | 2923 fps | 99.7% |
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 H&H Mag. loaded with the .307 | 150gr | Rhino Solid Shank. Alliant Power Pro 2000-MR delivers the highest muzzle velocity at 3,196 fps; across all powders the maximum-charge window runs from 1,913 fps to 3,196 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 (430 MPa), the top charges use 58–90 %, leaving at least 10 % headroom. The 150.0 gr projectile in 0.307" calls for a 1:16.5 twist; slower twists will usually not stabilise this weight. Accurate 3100, ADI AR 2209, Alliant Power Pro Varmint 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-16, ReloadSwiss RS 70, Ramshot Hunter rank at the top here: for .300 H&H Mag. with the .307 | 150gr | Rhino Solid Shank 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.