Load Specifications
Load data in caliber .300 Blaser Mag. with .308 | 150gr | Barnes MRX BT bullet and 95 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 70, Hodgdon Superformance and Alliant Reloder-17.
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: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 84% | 51,938 psi | 85% | 3002 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 54,592 psi | 90% | 3068 fps | 97.7% |
| Accurate 3100ᴾ | <<locked>> | 100% | 47,050 psi | 77% | 3025 fps | 98% |
| Accurate 4064 | <<locked>> | 86% | 52,388 psi | 86% | 3058 fps | 100% |
| Accurate 4350 | <<locked>> | 94% | 52,895 psi | 87% | 3156 fps | 99.8% |
| ADI AR 2206H | <<locked>> | 82% | 52,402 psi | 86% | 3094 fps | 100% |
| ADI AR 2208 | <<locked>> | 88% | 53,693 psi | 88% | 3097 fps | 99.9% |
| ADI AR 2209ᴾ | <<locked>> | 100% | 54,839 psi | 90% | 3199 fps | 97.1% |
| ADI Benchmark 8208 | <<locked>> | 82% | 54,665 psi | 90% | 3094 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 84% | 52,475 psi | 86% | 3222 fps | 99.9% |
| Alliant Power Pro Varmintᴾ | <<locked>> | 100% | 54,650 psi | 90% | 3196 fps | 97.1% |
| Alliant Reloder- TS 15.5 | <<locked>> | 88% | 54,070 psi | 89% | 3123 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 86% | 54,259 psi | 89% | 3143 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 96% | 54,085 psi | 89% | 3222 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 90% | 51,648 psi | 85% | 3196 fps | 100% |
| Alliant Reloder-19ᴾ | <<locked>> | 100% | 53,838 psi | 88% | 3182 fps | 97% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 44,324 psi | 73% | 3051 fps | 99.9% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 38,943 psi | 64% | 2943 fps | 96.5% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 50,821 psi | 83% | 3251 fps | 99.7% |
| Baschieri & Pellagri 107 | <<locked>> | 82% | 52,228 psi | 86% | 3104 fps | 99.8% |
| Bofors RP3 | <<locked>> | 88% | 54,621 psi | 90% | 3136 fps | 100% |
| Bofors RP7 | <<locked>> | 92% | 54,433 psi | 89% | 3110 fps | 97.9% |
| Hodgdon BL-C2 | <<locked>> | 82% | 54,230 psi | 89% | 3120 fps | 100% |
| Hodgdon H380 | <<locked>> | 86% | 51,634 psi | 85% | 3091 fps | 99.4% |
| Hodgdon H414 | <<locked>> | 92% | 52,069 psi | 85% | 3153 fps | 98.1% |
| Hodgdon H4350 | <<locked>> | 90% | 52,388 psi | 86% | 3110 fps | 96.9% |
| Hodgdon H4895 | <<locked>> | 82% | 52,997 psi | 87% | 3104 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 98% | 54,157 psi | 89% | 3140 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 84% | 52,982 psi | 87% | 3140 fps | 100% |
| Hodgdon Superformance | <<locked>> | 92% | 52,359 psi | 86% | 3186 fps | 97.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,708 psi | 59% | 1959 fps | 100% |
| Hodgdon VARGET | <<locked>> | 84% | 54,186 psi | 89% | 3107 fps | 100% |
| IMR 3031 | <<locked>> | 82% | 53,287 psi | 87% | 3084 fps | 100% |
| IMR 4064 | <<locked>> | 86% | 53,026 psi | 87% | 3077 fps | 99.9% |
| IMR 4166 Enduron | <<locked>> | 84% | 52,562 psi | 86% | 3051 fps | 98.1% |
| IMR 4350 | <<locked>> | 94% | 51,808 psi | 85% | 3081 fps | 97.5% |
| IMR 4451 Enduron | <<locked>> | 90% | 52,852 psi | 87% | 3084 fps | 98.1% |
| IMR 4831 | <<locked>> | 96% | 53,722 psi | 88% | 3153 fps | 99.8% |
| IMR 4895 | <<locked>> | 84% | 52,214 psi | 86% | 3117 fps | 100% |
| IMR 8208 XBR | <<locked>> | 82% | 54,665 psi | 90% | 3094 fps | 100% |
| Lovex D073.6 | <<locked>> | 82% | 52,272 psi | 86% | 3064 fps | 100% |
| Lovex S060 | <<locked>> | 84% | 55,071 psi | 90% | 3071 fps | 100% |
| Lovex S062 | <<locked>> | 86% | 52,866 psi | 87% | 3071 fps | 100% |
| Lovex S065 | <<locked>> | 92% | 52,620 psi | 86% | 3081 fps | 99.1% |
| Lovex S070 | <<locked>> | 94% | 53,534 psi | 88% | 3117 fps | 98.5% |
| Lovex S071ᴾ | <<locked>> | 100% | 38,653 psi | 63% | 2851 fps | 95.9% |
| Norma 201 | <<locked>> | 84% | 54,346 psi | 89% | 3084 fps | 100% |
| Norma 202 | <<locked>> | 82% | 51,808 psi | 85% | 3035 fps | 100% |
| Norma 203B | <<locked>> | 86% | 53,490 psi | 88% | 3127 fps | 100% |
| Norma 204 | <<locked>> | 94% | 52,228 psi | 86% | 3130 fps | 96.4% |
| Norma MRPᴾ | <<locked>> | 100% | 50,125 psi | 82% | 3199 fps | 97.8% |
| Norma URP | <<locked>> | 94% | 52,011 psi | 85% | 3143 fps | 99.7% |
| Ramshot Big Game | <<locked>> | 86% | 54,418 psi | 89% | 3153 fps | 100% |
| Ramshot Hunter | <<locked>> | 96% | 54,520 psi | 90% | 3199 fps | 99.1% |
| Ramshot TAC | <<locked>> | 82% | 54,955 psi | 90% | 3117 fps | 99.4% |
| Ramshot Wild Boar | <<locked>> | 82% | 54,897 psi | 90% | 3133 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 36,230 psi | 59% | 2005 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 52,069 psi | 85% | 3074 fps | 98.5% |
| ReloadSwiss RS 52 | <<locked>> | 84% | 55,114 psi | 90% | 3215 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 90% | 55,042 psi | 90% | 3251 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 94% | 52,852 psi | 87% | 3179 fps | 99.7% |
| ReloadSwiss RS 70 | <<locked>> | 94% | 52,040 psi | 85% | 3209 fps | 99.6% |
| Rottweil R 902 | <<locked>> | 86% | 55,042 psi | 90% | 3087 fps | 100% |
| Rottweil R 903 | <<locked>> | 90% | 54,491 psi | 89% | 3127 fps | 100% |
| Rottweil R 905ᴾ | <<locked>> | 100% | 52,707 psi | 87% | 3163 fps | 96.9% |
| Rottweil R 907 | <<locked>> | 92% | 54,433 psi | 89% | 3110 fps | 97.9% |
| Shooters World Long Rifle | <<locked>> | 92% | 52,620 psi | 86% | 3081 fps | 99.1% |
| Shooters World Match Rifle | <<locked>> | 82% | 52,272 psi | 86% | 3064 fps | 100% |
| Shooters World Precision | <<locked>> | 86% | 52,866 psi | 87% | 3071 fps | 100% |
| Shooters World SW4350 | <<locked>> | 94% | 53,534 psi | 88% | 3117 fps | 98.5% |
| SNPE Vectan SP 11 | <<locked>> | 88% | 52,808 psi | 87% | 3133 fps | 100% |
| SNPE Vectan SP 7 | <<locked>> | 82% | 53,359 psi | 88% | 3087 fps | 99.5% |
| SNPE Vectan SP 9 | <<locked>> | 84% | 54,418 psi | 89% | 3117 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 52,272 psi | 86% | 2969 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 88% | 52,968 psi | 87% | 2969 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 52,359 psi | 86% | 3025 fps | 98.1% |
| SNPE Vectan Tubal 8000ᴾ | <<locked>> | 100% | 52,228 psi | 86% | 3159 fps | 96.8% |
| Somchem S335 | <<locked>> | 84% | 55,114 psi | 90% | 3015 fps | 100% |
| Somchem S341 | <<locked>> | 82% | 53,127 psi | 87% | 3077 fps | 100% |
| Somchem S355 | <<locked>> | 90% | 54,766 psi | 90% | 3127 fps | 100% |
| Somchem S365 | <<locked>> | 98% | 54,230 psi | 89% | 3199 fps | 100% |
| Somchem S385ᴾ | <<locked>> | 100% | 53,388 psi | 88% | 3136 fps | 97.8% |
| Vihtavuori N133 | <<locked>> | 82% | 52,750 psi | 87% | 2953 fps | 100% |
| Vihtavuori N135 | <<locked>> | 84% | 51,663 psi | 85% | 2995 fps | 100% |
| Vihtavuori N140 | <<locked>> | 84% | 52,301 psi | 86% | 3012 fps | 100% |
| Vihtavuori N150 | <<locked>> | 90% | 52,634 psi | 86% | 3048 fps | 100% |
| Vihtavuori N160 | <<locked>> | 94% | 54,375 psi | 89% | 3140 fps | 99.8% |
| Vihtavuori N540 | <<locked>> | 86% | 53,896 psi | 88% | 3058 fps | 100% |
| Vihtavuori N550 | <<locked>> | 94% | 53,548 psi | 88% | 3146 fps | 99.7% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 49,487 psi | 81% | 3136 fps | 99.8% |
| Winchester 6.5 StaBALL | <<locked>> | 94% | 54,578 psi | 90% | 3114 fps | 100% |
| Winchester 760 | <<locked>> | 92% | 52,301 psi | 86% | 3156 fps | 98.2% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 39,929 psi | 66% | 3084 fps | 100% |
| Winchester StaBALL Match | <<locked>> | 84% | 54,491 psi | 89% | 3127 fps | 100% |
| Winchester Supreme 780ᴾ | <<locked>> | 100% | 50,125 psi | 82% | 3068 fps | 96% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 80% | 45,353 psi | 74% | 2897 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 44,527 psi | 73% | 2884 fps | 95.5% |
| Accurate 3100 | <<locked>> | 94% | 37,898 psi | 62% | 2835 fps | 95.6% |
| Accurate 4064 | <<locked>> | 80% | 42,946 psi | 71% | 2897 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 32,097 psi | 53% | 2710 fps | 95.3% |
| ADI AR 2206H | <<locked>> | 80% | 49,153 psi | 81% | 3035 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 80% | 41,713 psi | 68% | 2871 fps | 98.7% |
| ADI AR 2209 | <<locked>> | 96% | 47,819 psi | 79% | 3068 fps | 95.4% |
| ADI Benchmark 8208 | <<locked>> | 80% | 51,329 psi | 84% | 3038 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 45,310 psi | 74% | 3081 fps | 99.3% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 47,732 psi | 78% | 3068 fps | 95.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 41,669 psi | 68% | 2894 fps | 99.6% |
| Alliant Reloder-15 | <<locked>> | 80% | 44,715 psi | 73% | 2969 fps | 99.3% |
| Alliant Reloder-16 | <<locked>> | 80% | 32,242 psi | 53% | 2733 fps | 95.4% |
| Alliant Reloder-17 | 63.8 gr | 80% | 36,158 psi | 59% | 2867 fps | 98.6% |
| Alliant Reloder-19 | <<locked>> | 96% | 47,094 psi | 77% | 3054 fps | 95.4% |
| Alliant Reloder-23 | <<locked>> | 86% | 28,094 psi | 46% | 2628 fps | 95.1% |
| Alliant Reloder-25 | <<locked>> | 98% | 36,347 psi | 60% | 2874 fps | 95.4% |
| Alliant Reloder-26 | <<locked>> | 90% | 34,925 psi | 57% | 2887 fps | 95.9% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 48,805 psi | 80% | 3041 fps | 99.5% |
| Bofors RP3 | <<locked>> | 80% | 41,437 psi | 68% | 2897 fps | 99.6% |
| Bofors RP7 | <<locked>> | 84% | 42,105 psi | 69% | 2871 fps | 95% |
| Hodgdon BL-C2 | <<locked>> | 80% | 50,633 psi | 83% | 3061 fps | 100% |
| Hodgdon H380 | <<locked>> | 80% | 42,206 psi | 69% | 2904 fps | 97.9% |
| Hodgdon H414 | <<locked>> | 84% | 39,639 psi | 65% | 2897 fps | 95% |
| Hodgdon H4350 | <<locked>> | 86% | 45,861 psi | 75% | 2986 fps | 95.3% |
| Hodgdon H4895 | <<locked>> | 80% | 49,705 psi | 82% | 3048 fps | 100% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 29,588 psi | 49% | 2621 fps | 96.2% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 46,093 psi | 76% | 3018 fps | 100% |
| Hodgdon Superformance | 72.5 gr | 86% | 41,858 psi | 69% | 2972 fps | 95.2% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,585 psi | 44% | 1752 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 47,630 psi | 78% | 2992 fps | 99.9% |
| IMR 3031 | <<locked>> | 80% | 49,777 psi | 82% | 3028 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 43,816 psi | 72% | 2907 fps | 99.2% |
| IMR 4166 Enduron | <<locked>> | 80% | 46,311 psi | 76% | 2933 fps | 96.8% |
| IMR 4350 | <<locked>> | 88% | 42,786 psi | 70% | 2904 fps | 95.3% |
| IMR 4451 Enduron | <<locked>> | 82% | 41,060 psi | 67% | 2848 fps | 95.2% |
| IMR 4831 | <<locked>> | 82% | 33,431 psi | 55% | 2730 fps | 95.9% |
| IMR 4895 | <<locked>> | 80% | 45,876 psi | 75% | 2999 fps | 99.7% |
| IMR 8208 XBR | <<locked>> | 80% | 51,329 psi | 84% | 3038 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 48,733 psi | 80% | 3005 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 48,573 psi | 80% | 2959 fps | 99.8% |
| Lovex S062 | <<locked>> | 80% | 43,700 psi | 72% | 2907 fps | 99.9% |
| Lovex S065 | <<locked>> | 80% | 35,810 psi | 59% | 2730 fps | 95.1% |
| Lovex S070 | <<locked>> | 86% | 41,423 psi | 68% | 2881 fps | 95.8% |
| Lovex S071 | <<locked>> | 98% | 36,187 psi | 59% | 2792 fps | 95% |
| Norma 201 | <<locked>> | 80% | 47,776 psi | 78% | 2976 fps | 100% |
| Norma 202 | <<locked>> | 80% | 48,559 psi | 80% | 2982 fps | 100% |
| Norma 203B | <<locked>> | 80% | 44,048 psi | 72% | 2953 fps | 99.5% |
| Norma 204 | <<locked>> | 92% | 48,863 psi | 80% | 3068 fps | 95.6% |
| Norma MRP | <<locked>> | 94% | 40,451 psi | 66% | 2992 fps | 95% |
| Norma URP | <<locked>> | 80% | 32,416 psi | 53% | 2717 fps | 95.2% |
| Ramshot Big Game | <<locked>> | 80% | 44,005 psi | 72% | 2969 fps | 99.4% |
| Ramshot Hunter | <<locked>> | 86% | 38,856 psi | 64% | 2887 fps | 95.7% |
| Ramshot TAC | <<locked>> | 80% | 51,256 psi | 84% | 3051 fps | 99% |
| Ramshot Wild Boar | <<locked>> | 80% | 51,126 psi | 84% | 3071 fps | 99.9% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,963 psi | 44% | 1795 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 42,482 psi | 70% | 2887 fps | 96.5% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 47,747 psi | 78% | 3084 fps | 99.6% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 38,508 psi | 63% | 2940 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 82% | 34,389 psi | 56% | 2792 fps | 95.8% |
| ReloadSwiss RS 70 | 68.1 gr | 84% | 36,550 psi | 60% | 2867 fps | 96% |
| Rottweil R 902 | <<locked>> | 80% | 45,542 psi | 75% | 2923 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 38,943 psi | 64% | 2838 fps | 99.1% |
| Rottweil R 905 | <<locked>> | 96% | 45,992 psi | 76% | 3038 fps | 95.3% |
| Rottweil R 907 | <<locked>> | 84% | 42,105 psi | 69% | 2871 fps | 95% |
| Shooters World Long Rifle | <<locked>> | 80% | 35,810 psi | 59% | 2730 fps | 95.1% |
| Shooters World Match Rifle | <<locked>> | 80% | 48,733 psi | 80% | 3005 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 43,700 psi | 72% | 2907 fps | 99.9% |
| Shooters World SW4350 | <<locked>> | 86% | 41,423 psi | 68% | 2881 fps | 95.8% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 40,147 psi | 66% | 2894 fps | 98.8% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 49,806 psi | 82% | 3028 fps | 99.1% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 47,543 psi | 78% | 2995 fps | 99.8% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 49,182 psi | 81% | 2920 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 41,191 psi | 68% | 2772 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 40,089 psi | 66% | 2785 fps | 95.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 45,542 psi | 75% | 3028 fps | 95.1% |
| Somchem S335 | <<locked>> | 80% | 48,631 psi | 80% | 2913 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 49,661 psi | 82% | 3018 fps | 99.9% |
| Somchem S355 | <<locked>> | 80% | 39,537 psi | 65% | 2841 fps | 99.1% |
| Somchem S365 | <<locked>> | 80% | 28,935 psi | 48% | 2657 fps | 97.4% |
| Somchem S385 | <<locked>> | 94% | 43,613 psi | 72% | 2956 fps | 95.6% |
| Vihtavuori N133 | <<locked>> | 80% | 49,676 psi | 82% | 2907 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 45,556 psi | 75% | 2897 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 45,977 psi | 75% | 2907 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 37,797 psi | 62% | 2769 fps | 99.6% |
| Vihtavuori N160 | <<locked>> | 80% | 33,866 psi | 56% | 2723 fps | 95.8% |
| Vihtavuori N540 | <<locked>> | 80% | 44,353 psi | 73% | 2897 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 33,315 psi | 55% | 2720 fps | 95.3% |
| Vihtavuori N555 | <<locked>> | 86% | 30,501 psi | 50% | 2707 fps | 95.3% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 33,446 psi | 55% | 2694 fps | 98% |
| Winchester 760 | <<locked>> | 84% | 39,639 psi | 65% | 2897 fps | 95% |
| Winchester StaBALL HD | <<locked>> | 90% | 28,282 psi | 46% | 2713 fps | 96% |
| Winchester StaBALL Match | <<locked>> | 80% | 47,500 psi | 78% | 3005 fps | 99.9% |
| Winchester Supreme 780 | <<locked>> | 98% | 46,760 psi | 77% | 3005 fps | 95.2% |
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 95 powders for .300 Blaser Mag. loaded with the .308 | 150gr | Barnes MRX BT. Alliant Reloder-26 delivers the highest muzzle velocity at 3,251 fps; across all powders the maximum-charge window runs from 1,959 fps to 3,251 fps. Accurate 3100 gives the best case fill at 100 %, and 95 of the 95 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (420 MPa), the top charges use 59–90 %, leaving at least 10 % headroom. The 150.0 gr projectile in 0.308" calls for a 1:11.5 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. ReloadSwiss RS 70, Hodgdon Superformance, Alliant Reloder-17 rank at the top here: for .300 Blaser Mag. with the .308 | 150gr | Barnes MRX BT 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.