Load Specifications
Bullet Manufacturer:Sierra
Bullet Weight:177 gr
Bullet Diameter:0.308"
Bullet Length:<<locked>>
Caliber:.300 Blaser Mag. load data
Case Length (l3):2.519"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:92.4 Grains of Water
Primer Size:Large Rifle Magnum (LRM)
Barrel Length:25.6"
Max. allowed Pressure:60,916 psi
Recommended Twist Rate:1:12.5
Load data in caliber .300 Blaser Mag. with .308 | 177gr | Sierra Hollow Point Boat Tail - Closed Nose bullet and 83 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: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2700 | <<locked>> | 82% | 54,781 psi | 90% | 2864 fps | 99.2% |
| Accurate 3100 | <<locked>> | 98% | 53,287 psi | 87% | 2917 fps | 99.8% |
| Accurate 4064 | <<locked>> | 82% | 54,433 psi | 89% | 2848 fps | 100% |
| Accurate 4350 | <<locked>> | 88% | 51,793 psi | 85% | 2910 fps | 100% |
| Accurate High Country | <<locked>> | 96% | 54,534 psi | 90% | 3064 fps | 98.1% |
| Accurate MAGPRO | <<locked>> | 96% | 51,619 psi | 85% | 2999 fps | 96.2% |
| ADI AR 2208 | <<locked>> | 84% | 54,201 psi | 89% | 2881 fps | 100% |
| ADI AR 2209 | <<locked>> | 94% | 52,663 psi | 86% | 2953 fps | 98.4% |
| ADI AR 2213 | <<locked>> | 98% | 53,766 psi | 88% | 3005 fps | 97.6% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 37,130 psi | 61% | 2717 fps | 96.4% |
| Alliant Power Pro Varmint | <<locked>> | 94% | 52,866 psi | 87% | 2953 fps | 98.5% |
| Alliant Reloder- TS 15.5 | <<locked>> | 82% | 51,924 psi | 85% | 2854 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 90% | 52,533 psi | 86% | 2966 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 53,664 psi | 88% | 2989 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 94% | 52,185 psi | 86% | 2943 fps | 98.4% |
| Alliant Reloder-22 | <<locked>> | 98% | 52,953 psi | 87% | 3002 fps | 98.7% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 53,751 psi | 88% | 2986 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 46,528 psi | 76% | 2920 fps | 99.8% |
| Alliant Reloder-26 | <<locked>> | 96% | 53,824 psi | 88% | 3074 fps | 100% |
| Bofors RP15ᴾ | <<locked>> | 100% | 51,938 psi | 85% | 2986 fps | 98.4% |
| Bofors RP3 | <<locked>> | 82% | 52,605 psi | 86% | 2871 fps | 100% |
| Bofors RP5 | <<locked>> | 98% | 52,953 psi | 87% | 3002 fps | 98.7% |
| Bofors RP7 | <<locked>> | 86% | 51,909 psi | 85% | 2858 fps | 99% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 46,180 psi | 76% | 2854 fps | 96.6% |
| Hodgdon H380 | <<locked>> | 82% | 52,692 psi | 87% | 2884 fps | 100% |
| Hodgdon H414 | <<locked>> | 88% | 53,679 psi | 88% | 2959 fps | 99.5% |
| Hodgdon H4350 | <<locked>> | 86% | 53,534 psi | 88% | 2920 fps | 98.8% |
| Hodgdon H4831 | <<locked>> | 96% | 54,041 psi | 89% | 2949 fps | 97% |
| Hodgdon H4831 SC | <<locked>> | 96% | 52,852 psi | 87% | 2930 fps | 96.7% |
| Hodgdon Hybrid 100V | <<locked>> | 92% | 52,823 psi | 87% | 2887 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 45,658 psi | 75% | 2963 fps | 98.1% |
| Hodgdon Superformance | <<locked>> | 88% | 53,838 psi | 88% | 2999 fps | 99.4% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,593 psi | 60% | 1824 fps | 100% |
| IMR 4064 | <<locked>> | 82% | 53,606 psi | 88% | 2861 fps | 100% |
| IMR 4350 | <<locked>> | 90% | 52,953 psi | 87% | 2894 fps | 99.1% |
| IMR 4451 Enduron | <<locked>> | 86% | 53,621 psi | 88% | 2884 fps | 99.4% |
| IMR 4831 | <<locked>> | 90% | 52,330 psi | 86% | 2904 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 94% | 52,199 psi | 86% | 2881 fps | 96.8% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 54,984 psi | 90% | 3038 fps | 97.9% |
| Lovex S062 | <<locked>> | 82% | 54,085 psi | 89% | 2858 fps | 100% |
| Lovex S065 | <<locked>> | 88% | 53,737 psi | 88% | 2881 fps | 99.9% |
| Lovex S070 | <<locked>> | 88% | 51,663 psi | 85% | 2871 fps | 99.4% |
| Lovex S071ᴾ | <<locked>> | 100% | 47,485 psi | 78% | 2822 fps | 99.4% |
| Norma 203B | <<locked>> | 82% | 54,694 psi | 90% | 2913 fps | 100% |
| Norma 204 | <<locked>> | 90% | 53,751 psi | 88% | 2946 fps | 98.4% |
| Norma MRP | <<locked>> | 96% | 52,663 psi | 86% | 3028 fps | 99.5% |
| Norma URP | <<locked>> | 90% | 54,085 psi | 89% | 2949 fps | 100% |
| Ramshot Grand | <<locked>> | 98% | 51,605 psi | 85% | 2992 fps | 97.6% |
| Ramshot Hunter | <<locked>> | 90% | 52,852 psi | 87% | 2949 fps | 99.8% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 49,661 psi | 82% | 2930 fps | 98.7% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,318 psi | 61% | 1867 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 52,620 psi | 86% | 2867 fps | 99.6% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 53,156 psi | 87% | 2976 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 51,605 psi | 85% | 2930 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 53,534 psi | 88% | 3015 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 45,730 psi | 75% | 2956 fps | 99% |
| Rottweil R 903 | <<locked>> | 84% | 52,692 psi | 87% | 2867 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 54,375 psi | 89% | 2927 fps | 97.7% |
| Rottweil R 905 | <<locked>> | 96% | 54,810 psi | 90% | 2982 fps | 98.9% |
| Rottweil R 907 | <<locked>> | 86% | 51,909 psi | 85% | 2858 fps | 99% |
| Shooters World Long Rifle | <<locked>> | 88% | 53,737 psi | 88% | 2881 fps | 99.9% |
| Shooters World Precision | <<locked>> | 82% | 54,085 psi | 89% | 2858 fps | 100% |
| Shooters World SW4350 | <<locked>> | 88% | 51,663 psi | 85% | 2871 fps | 99.4% |
| SNPE Vectan SP 11 | <<locked>> | 84% | 54,128 psi | 89% | 2923 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 84% | 53,447 psi | 88% | 2749 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 88% | 53,185 psi | 87% | 2831 fps | 99.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 54,331 psi | 89% | 2979 fps | 98.8% |
| Somchem S355 | <<locked>> | 84% | 52,663 psi | 86% | 2861 fps | 100% |
| Somchem S361 | <<locked>> | 92% | 52,286 psi | 86% | 2858 fps | 96.6% |
| Somchem S365 | <<locked>> | 92% | 53,650 psi | 88% | 2949 fps | 100% |
| Somchem S385 | <<locked>> | 94% | 51,924 psi | 85% | 2904 fps | 99% |
| Vihtavuori N150 | <<locked>> | 86% | 53,809 psi | 88% | 2835 fps | 100% |
| Vihtavuori N160 | <<locked>> | 88% | 52,562 psi | 86% | 2887 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 54,926 psi | 90% | 2936 fps | 99.1% |
| Vihtavuori N540 | <<locked>> | 82% | 54,549 psi | 90% | 2835 fps | 100% |
| Vihtavuori N550 | <<locked>> | 88% | 51,590 psi | 85% | 2890 fps | 100% |
| Vihtavuori N555 | <<locked>> | 96% | 52,823 psi | 87% | 2959 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 52,895 psi | 87% | 3018 fps | 97.1% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 48,414 psi | 79% | 2923 fps | 96.4% |
| Winchester 6.5 StaBALL | <<locked>> | 88% | 51,909 psi | 85% | 2851 fps | 100% |
| Winchester 760 | <<locked>> | 88% | 53,925 psi | 89% | 2963 fps | 99.6% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 49,458 psi | 81% | 3061 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 96% | 51,938 psi | 85% | 2897 fps | 98.3% |
Start Load - Barrel Length: 25.6"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2700 | <<locked>> | 80% | 51,271 psi | 84% | 2808 fps | 98.7% |
| Accurate 3100 | <<locked>> | 82% | 31,038 psi | 51% | 2470 fps | 95.1% |
| Accurate 4064 | <<locked>> | 80% | 51,097 psi | 84% | 2799 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 39,233 psi | 64% | 2680 fps | 99.1% |
| Accurate High Country | <<locked>> | 90% | 44,222 psi | 73% | 2874 fps | 95.7% |
| Accurate MAGPRO | <<locked>> | 94% | 48,153 psi | 79% | 2936 fps | 95.3% |
| ADI AR 2208 | <<locked>> | 80% | 48,066 psi | 79% | 2779 fps | 100% |
| ADI AR 2209 | <<locked>> | 86% | 40,538 psi | 67% | 2720 fps | 95.5% |
| ADI AR 2213 | <<locked>> | 92% | 44,077 psi | 72% | 2818 fps | 95.1% |
| ADI AR 2225 | <<locked>> | 98% | 34,780 psi | 57% | 2651 fps | 95.2% |
| Alliant Power Pro Varmint | <<locked>> | 86% | 40,625 psi | 67% | 2720 fps | 95.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 48,776 psi | 80% | 2805 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 38,145 psi | 63% | 2690 fps | 99.2% |
| Alliant Reloder-17 | <<locked>> | 80% | 43,250 psi | 71% | 2812 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 86% | 40,205 psi | 66% | 2710 fps | 95.5% |
| Alliant Reloder-22 | <<locked>> | 90% | 40,712 psi | 67% | 2769 fps | 95.9% |
| Alliant Reloder-23 | <<locked>> | 80% | 28,021 psi | 46% | 2444 fps | 97.6% |
| Alliant Reloder-25 | <<locked>> | 88% | 31,778 psi | 52% | 2569 fps | 96% |
| Alliant Reloder-26 | <<locked>> | 80% | 29,921 psi | 49% | 2556 fps | 96% |
| Bofors RP15 | <<locked>> | 92% | 40,161 psi | 66% | 2753 fps | 95.5% |
| Bofors RP3 | <<locked>> | 80% | 49,153 psi | 81% | 2815 fps | 100% |
| Bofors RP5 | <<locked>> | 90% | 40,712 psi | 67% | 2769 fps | 95.9% |
| Bofors RP7 | <<locked>> | 80% | 43,018 psi | 71% | 2690 fps | 97.4% |
| Hodgdon H1000 | <<locked>> | 98% | 43,236 psi | 71% | 2795 fps | 95.7% |
| Hodgdon H380 | <<locked>> | 80% | 49,443 psi | 81% | 2831 fps | 99.9% |
| Hodgdon H414 | <<locked>> | 80% | 41,089 psi | 67% | 2726 fps | 97.5% |
| Hodgdon H4350 | <<locked>> | 80% | 44,005 psi | 72% | 2746 fps | 96.9% |
| Hodgdon H4831 | <<locked>> | 92% | 47,224 psi | 78% | 2831 fps | 95.4% |
| Hodgdon H4831 SC | <<locked>> | 92% | 46,224 psi | 76% | 2812 fps | 95.1% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 35,752 psi | 59% | 2579 fps | 99.6% |
| Hodgdon Retumbo | <<locked>> | 94% | 37,637 psi | 62% | 2766 fps | 95.1% |
| Hodgdon Superformance | <<locked>> | 80% | 40,103 psi | 66% | 2740 fps | 96.9% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,296 psi | 45% | 1627 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 50,546 psi | 83% | 2812 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 38,653 psi | 63% | 2618 fps | 96.2% |
| IMR 4451 Enduron | <<locked>> | 80% | 44,411 psi | 73% | 2720 fps | 98.1% |
| IMR 4831 | <<locked>> | 80% | 37,623 psi | 62% | 2628 fps | 98.9% |
| IMR 4955 Enduron | <<locked>> | 90% | 45,963 psi | 75% | 2769 fps | 95.2% |
| IMR 7828 SSC | <<locked>> | 94% | 45,020 psi | 74% | 2854 fps | 95.5% |
| Lovex S062 | <<locked>> | 80% | 50,792 psi | 83% | 2805 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 41,974 psi | 69% | 2671 fps | 98.7% |
| Lovex S070 | <<locked>> | 80% | 40,306 psi | 66% | 2654 fps | 97.4% |
| Lovex S071 | <<locked>> | 88% | 32,329 psi | 53% | 2503 fps | 95.7% |
| Norma 203B | <<locked>> | 80% | 51,155 psi | 84% | 2858 fps | 100% |
| Norma 204 | <<locked>> | 82% | 40,828 psi | 67% | 2703 fps | 95.5% |
| Norma MRP | <<locked>> | 84% | 34,679 psi | 57% | 2654 fps | 95.2% |
| Norma URP | <<locked>> | 80% | 39,001 psi | 64% | 2674 fps | 99% |
| Ramshot Grand | <<locked>> | 94% | 44,875 psi | 74% | 2864 fps | 95.9% |
| Ramshot Hunter | <<locked>> | 80% | 37,724 psi | 62% | 2657 fps | 97.4% |
| Ramshot Magnum | <<locked>> | 92% | 37,072 psi | 61% | 2671 fps | 95.3% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 27,818 psi | 46% | 1667 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 49,298 psi | 81% | 2812 fps | 99.3% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 45,934 psi | 75% | 2864 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 39,117 psi | 64% | 2700 fps | 98.9% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 37,695 psi | 62% | 2707 fps | 98.5% |
| ReloadSwiss RS 76 | <<locked>> | 94% | 36,912 psi | 61% | 2746 fps | 96.1% |
| Rottweil R 903 | <<locked>> | 80% | 46,325 psi | 76% | 2762 fps | 100% |
| Rottweil R 904 | <<locked>> | 88% | 44,773 psi | 74% | 2753 fps | 95.6% |
| Rottweil R 905 | <<locked>> | 86% | 39,320 psi | 65% | 2694 fps | 95.5% |
| Rottweil R 907 | <<locked>> | 80% | 43,018 psi | 71% | 2690 fps | 97.4% |
| Shooters World Long Rifle | <<locked>> | 80% | 41,974 psi | 69% | 2671 fps | 98.7% |
| Shooters World Precision | <<locked>> | 80% | 50,792 psi | 83% | 2805 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 40,306 psi | 66% | 2654 fps | 97.4% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 47,369 psi | 78% | 2815 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 47,253 psi | 78% | 2657 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 41,147 psi | 68% | 2615 fps | 97.5% |
| SNPE Vectan Tubal 8000 | <<locked>> | 86% | 38,972 psi | 64% | 2687 fps | 95.3% |
| Somchem S355 | <<locked>> | 80% | 46,470 psi | 76% | 2759 fps | 100% |
| Somchem S361 | <<locked>> | 88% | 45,919 psi | 75% | 2746 fps | 95% |
| Somchem S365 | <<locked>> | 80% | 35,462 psi | 58% | 2628 fps | 100% |
| Somchem S385 | <<locked>> | 84% | 37,478 psi | 62% | 2621 fps | 95.8% |
| Vihtavuori N150 | <<locked>> | 80% | 44,440 psi | 73% | 2687 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 40,292 psi | 66% | 2667 fps | 99.2% |
| Vihtavuori N165 | <<locked>> | 88% | 36,956 psi | 61% | 2602 fps | 95.1% |
| Vihtavuori N540 | <<locked>> | 80% | 51,314 psi | 84% | 2785 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 39,871 psi | 65% | 2674 fps | 99% |
| Vihtavuori N555 | <<locked>> | 80% | 31,154 psi | 51% | 2523 fps | 97.6% |
| Vihtavuori N560 | <<locked>> | 92% | 46,137 psi | 76% | 2894 fps | 95.4% |
| Vihtavuori N565 | <<locked>> | 98% | 45,339 psi | 74% | 2867 fps | 95.6% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 39,392 psi | 65% | 2638 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 41,292 psi | 68% | 2730 fps | 97.5% |
| Winchester StaBALL HD | <<locked>> | 80% | 24,743 psi | 41% | 2421 fps | 96.6% |
| Winchester Supreme 780 | <<locked>> | 88% | 39,291 psi | 65% | 2661 fps | 95.2% |
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 83 powders for .300 Blaser Mag. loaded with the .308 | 177gr | Sierra Hollow Point Boat Tail - Closed Nose . Alliant Reloder-26 delivers the highest muzzle velocity at 3,074 fps; across all powders the maximum-charge window runs from 1,824 fps to 3,074 fps. ADI AR 2225 gives the best case fill at 100 %, and 83 of the 83 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (420 MPa), the top charges use 60–90 %, 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-23, Alliant Reloder-25 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.