Load Specifications
Load data in caliber .270 Win. with .277 | 120gr | Barnes BND SPIT-FIRE bullet and 98 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Alliant Power Pro 2000-MR, ReloadSwiss RS 60 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.
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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 2015 | <<locked>> | 84% | 54,041 psi | 87% | 2920 fps | 100% |
| Accurate 2460 | <<locked>> | 82% | 56,202 psi | 90% | 2999 fps | 100% |
| Accurate 2495 | <<locked>> | 90% | 56,275 psi | 90% | 2992 fps | 100% |
| Accurate 2520 | <<locked>> | 84% | 54,520 psi | 87% | 3009 fps | 100% |
| Accurate 2700 | <<locked>> | 90% | 55,680 psi | 89% | 2982 fps | 96.2% |
| Accurate 4064 | <<locked>> | 92% | 56,260 psi | 90% | 3041 fps | 100% |
| Accurate 4350ᴾ | <<locked>> | 100% | 56,144 psi | 90% | 3120 fps | 99.3% |
| ADI AR 2206H | <<locked>> | 86% | 53,301 psi | 85% | 3018 fps | 99.6% |
| ADI AR 2208 | <<locked>> | 92% | 54,346 psi | 87% | 3015 fps | 99.4% |
| ADI Benchmark 8208 | <<locked>> | 86% | 55,709 psi | 89% | 3022 fps | 100% |
| Alliant AR-Comp | <<locked>> | 84% | 52,765 psi | 85% | 2949 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 88% | 52,794 psi | 85% | 3130 fps | 99.3% |
| Alliant Reloder- TS 15.5 | <<locked>> | 92% | 54,128 psi | 87% | 3038 fps | 99.9% |
| Alliant Reloder-15 | <<locked>> | 90% | 54,926 psi | 88% | 3064 fps | 99.5% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 53,809 psi | 86% | 3123 fps | 99.3% |
| Alliant Reloder-17 | <<locked>> | 96% | 55,158 psi | 88% | 3166 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 38,363 psi | 62% | 2828 fps | 97.6% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 43,033 psi | 69% | 2992 fps | 96.7% |
| Baschieri & Pellagri 107 | <<locked>> | 86% | 53,185 psi | 85% | 3031 fps | 99.1% |
| Bofors RP3 | <<locked>> | 92% | 54,868 psi | 88% | 3054 fps | 100% |
| Bofors RP7 | <<locked>> | 96% | 55,172 psi | 88% | 3018 fps | 96.4% |
| Hodgdon Benchmark | <<locked>> | 84% | 54,041 psi | 87% | 2956 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 86% | 55,027 psi | 88% | 3048 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 82% | 53,127 psi | 85% | 3091 fps | 99.4% |
| Hodgdon H322 | <<locked>> | 82% | 56,347 psi | 90% | 3018 fps | 100% |
| Hodgdon H380 | <<locked>> | 92% | 55,782 psi | 89% | 3064 fps | 98.9% |
| Hodgdon H414 | <<locked>> | 98% | 55,390 psi | 89% | 3114 fps | 97.2% |
| Hodgdon H4350 | <<locked>> | 96% | 56,144 psi | 90% | 3074 fps | 95.9% |
| Hodgdon H4895 | <<locked>> | 86% | 53,795 psi | 86% | 3028 fps | 99.8% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 49,908 psi | 80% | 2989 fps | 99.6% |
| Hodgdon LEVERevolution | <<locked>> | 88% | 53,055 psi | 85% | 3058 fps | 99.9% |
| Hodgdon Superformance | <<locked>> | 96% | 52,533 psi | 84% | 3084 fps | 96% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,447 psi | 57% | 1877 fps | 100% |
| Hodgdon VARGET | <<locked>> | 88% | 54,955 psi | 88% | 3031 fps | 99.9% |
| IMR 3031 | <<locked>> | 86% | 53,519 psi | 86% | 3018 fps | 100% |
| IMR 4064 | <<locked>> | 90% | 53,693 psi | 86% | 2995 fps | 99.4% |
| IMR 4166 Enduron | <<locked>> | 88% | 54,012 psi | 87% | 2976 fps | 96.7% |
| IMR 4350ᴾ | <<locked>> | 100% | 55,274 psi | 89% | 3041 fps | 96.4% |
| IMR 4451 Enduron | <<locked>> | 94% | 53,490 psi | 86% | 2995 fps | 96.5% |
| IMR 4831ᴾ | <<locked>> | 100% | 52,823 psi | 85% | 3048 fps | 99% |
| IMR 4895 | <<locked>> | 90% | 56,333 psi | 90% | 3097 fps | 99.8% |
| IMR 8208 XBR | <<locked>> | 86% | 55,709 psi | 89% | 3022 fps | 100% |
| Lovex D073.5 | <<locked>> | 82% | 56,101 psi | 90% | 3009 fps | 100% |
| Lovex D073.6 | <<locked>> | 88% | 56,434 psi | 90% | 3048 fps | 100% |
| Lovex S060 | <<locked>> | 88% | 56,289 psi | 90% | 2999 fps | 99.8% |
| Lovex S062 | <<locked>> | 90% | 53,461 psi | 86% | 2995 fps | 100% |
| Lovex S065 | <<locked>> | 98% | 56,391 psi | 90% | 3048 fps | 98.4% |
| Lovex S070 | <<locked>> | 98% | 53,606 psi | 86% | 3022 fps | 97% |
| Norma 201 | <<locked>> | 88% | 55,593 psi | 89% | 3018 fps | 100% |
| Norma 202 | <<locked>> | 88% | 55,927 psi | 90% | 3018 fps | 100% |
| Norma 203B | <<locked>> | 90% | 54,099 psi | 87% | 3048 fps | 99.7% |
| Norma URPᴾ | <<locked>> | 100% | 55,042 psi | 88% | 3104 fps | 99.1% |
| Ramshot Big Game | <<locked>> | 90% | 54,752 psi | 88% | 3074 fps | 99.7% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 54,085 psi | 87% | 3097 fps | 97.8% |
| Ramshot TAC | <<locked>> | 86% | 56,333 psi | 90% | 3041 fps | 98.5% |
| Ramshot Wild Boar | <<locked>> | 86% | 55,767 psi | 89% | 3058 fps | 99.8% |
| Ramshot X-Terminator | <<locked>> | 82% | 53,084 psi | 85% | 2966 fps | 99.5% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,752 psi | 57% | 1919 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 82% | 55,114 psi | 88% | 3002 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 92% | 56,420 psi | 90% | 3051 fps | 97.8% |
| ReloadSwiss RS 52 | <<locked>> | 88% | 55,100 psi | 88% | 3130 fps | 99.5% |
| ReloadSwiss RS 60 | <<locked>> | 94% | 54,694 psi | 88% | 3166 fps | 100% |
| ReloadSwiss RS 62ᴾ | <<locked>> | 100% | 55,883 psi | 90% | 3143 fps | 99.1% |
| ReloadSwiss RS 70ᴾ | <<locked>> | 100% | 55,579 psi | 89% | 3166 fps | 98.9% |
| Rottweil R 901 | <<locked>> | 84% | 53,011 psi | 85% | 2949 fps | 100% |
| Rottweil R 902 | <<locked>> | 90% | 55,883 psi | 90% | 3012 fps | 100% |
| Rottweil R 903 | <<locked>> | 94% | 54,679 psi | 88% | 3048 fps | 99.9% |
| Rottweil R 907 | <<locked>> | 96% | 55,172 psi | 88% | 3018 fps | 96.4% |
| Shooters World Long Rifle | <<locked>> | 98% | 56,391 psi | 90% | 3048 fps | 98.4% |
| Shooters World Match Rifle | <<locked>> | 88% | 56,434 psi | 90% | 3048 fps | 100% |
| Shooters World Precision | <<locked>> | 90% | 53,461 psi | 86% | 2995 fps | 100% |
| Shooters World SW4350 | <<locked>> | 98% | 53,606 psi | 86% | 3022 fps | 97% |
| SNPE Vectan SP 11 | <<locked>> | 92% | 52,968 psi | 85% | 3054 fps | 99.6% |
| SNPE Vectan SP 7 | <<locked>> | 86% | 54,592 psi | 88% | 3012 fps | 98.7% |
| SNPE Vectan SP 9 | <<locked>> | 88% | 55,027 psi | 88% | 3038 fps | 99.7% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 53,737 psi | 86% | 2907 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 53,679 psi | 86% | 2900 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 53,113 psi | 85% | 2936 fps | 96.5% |
| Somchem S321 | <<locked>> | 82% | 53,388 psi | 86% | 3002 fps | 100% |
| Somchem S335 | <<locked>> | 86% | 53,069 psi | 85% | 2907 fps | 100% |
| Somchem S341 | <<locked>> | 86% | 54,244 psi | 87% | 3009 fps | 99.7% |
| Somchem S355 | <<locked>> | 94% | 54,882 psi | 88% | 3041 fps | 99.9% |
| Somchem S365ᴾ | <<locked>> | 100% | 49,385 psi | 79% | 3048 fps | 100% |
| Vihtavuori N130 | <<locked>> | 82% | 53,330 psi | 86% | 2871 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 53,940 psi | 86% | 2894 fps | 100% |
| Vihtavuori N135 | <<locked>> | 90% | 55,492 psi | 89% | 2979 fps | 100% |
| Vihtavuori N140 | <<locked>> | 90% | 56,405 psi | 90% | 2995 fps | 100% |
| Vihtavuori N150 | <<locked>> | 94% | 53,084 psi | 85% | 2972 fps | 100% |
| Vihtavuori N160 | <<locked>> | 98% | 54,085 psi | 87% | 3048 fps | 99% |
| Vihtavuori N530 | <<locked>> | 86% | 56,275 psi | 90% | 3022 fps | 100% |
| Vihtavuori N540 | <<locked>> | 90% | 54,621 psi | 88% | 2989 fps | 100% |
| Vihtavuori N550 | <<locked>> | 98% | 53,258 psi | 85% | 3051 fps | 98.7% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 41,785 psi | 67% | 2910 fps | 97.5% |
| Winchester 6.5 StaBALL | <<locked>> | 98% | 54,795 psi | 88% | 3028 fps | 100% |
| Winchester 748 | <<locked>> | 86% | 56,289 psi | 90% | 3074 fps | 100% |
| Winchester 760 | <<locked>> | 98% | 55,709 psi | 89% | 3117 fps | 97.2% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 34,490 psi | 55% | 2808 fps | 96.9% |
| Winchester StaBALL Match | <<locked>> | 88% | 55,143 psi | 88% | 3051 fps | 99.9% |
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 2015 | <<locked>> | 80% | 47,935 psi | 77% | 2828 fps | 100% |
| Accurate 2460 | <<locked>> | 80% | 52,373 psi | 84% | 2943 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 40,538 psi | 65% | 2740 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 47,471 psi | 76% | 2897 fps | 100% |
| Accurate 2700 | <<locked>> | 88% | 52,228 psi | 84% | 2927 fps | 95.5% |
| Accurate 4064 | <<locked>> | 80% | 38,276 psi | 61% | 2726 fps | 99.8% |
| Accurate 4350 | <<locked>> | 88% | 36,912 psi | 59% | 2753 fps | 95.2% |
| ADI AR 2206H | <<locked>> | 80% | 44,179 psi | 71% | 2848 fps | 98.4% |
| ADI AR 2208 | <<locked>> | 80% | 37,492 psi | 60% | 2684 fps | 96% |
| ADI Benchmark 8208 | <<locked>> | 80% | 46,238 psi | 74% | 2861 fps | 99.5% |
| Alliant AR-Comp | <<locked>> | 80% | 46,180 psi | 74% | 2851 fps | 100% |
| Alliant Power Pro 2000-MR | 46.2 gr | 80% | 40,074 psi | 64% | 2867 fps | 96.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 36,941 psi | 59% | 2703 fps | 97.6% |
| Alliant Reloder-15 | <<locked>> | 80% | 39,900 psi | 64% | 2776 fps | 97% |
| Alliant Reloder-16 | <<locked>> | 88% | 36,912 psi | 59% | 2762 fps | 95.2% |
| Alliant Reloder-17 | 45.5 gr | 80% | 32,039 psi | 51% | 2657 fps | 95% |
| Alliant Reloder-23 | <<locked>> | 96% | 33,953 psi | 54% | 2710 fps | 95.8% |
| Alliant Reloder-26 | <<locked>> | 98% | 40,016 psi | 64% | 2917 fps | 95.5% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 43,424 psi | 70% | 2848 fps | 97.3% |
| Bofors RP3 | <<locked>> | 80% | 36,608 psi | 59% | 2707 fps | 97.6% |
| Bofors RP7 | <<locked>> | 94% | 51,721 psi | 83% | 2959 fps | 95.6% |
| Hodgdon Benchmark | <<locked>> | 80% | 47,877 psi | 77% | 2851 fps | 99.9% |
| Hodgdon BL-C2 | <<locked>> | 80% | 45,034 psi | 72% | 2877 fps | 99.7% |
| Hodgdon CFE223 | <<locked>> | 80% | 49,734 psi | 80% | 3031 fps | 99% |
| Hodgdon H322 | <<locked>> | 80% | 52,736 psi | 85% | 2966 fps | 100% |
| Hodgdon H380 | <<locked>> | 82% | 40,147 psi | 64% | 2769 fps | 95.7% |
| Hodgdon H414 | <<locked>> | 94% | 48,515 psi | 78% | 2992 fps | 95.6% |
| Hodgdon H4350 | <<locked>> | 94% | 52,634 psi | 84% | 3015 fps | 95% |
| Hodgdon H4895 | <<locked>> | 80% | 44,614 psi | 72% | 2861 fps | 98.9% |
| Hodgdon Hybrid 100V | <<locked>> | 86% | 31,908 psi | 51% | 2598 fps | 95.2% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 40,480 psi | 65% | 2822 fps | 98.5% |
| Hodgdon Superformance | <<locked>> | 94% | 48,878 psi | 78% | 3015 fps | 95% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,266 psi | 42% | 1677 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 42,656 psi | 68% | 2808 fps | 98.5% |
| IMR 3031 | <<locked>> | 80% | 44,048 psi | 71% | 2861 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 39,363 psi | 63% | 2723 fps | 96.9% |
| IMR 4166 Enduron | <<locked>> | 84% | 47,601 psi | 76% | 2861 fps | 95.2% |
| IMR 4350 | <<locked>> | 98% | 51,808 psi | 83% | 2982 fps | 95.7% |
| IMR 4451 Enduron | <<locked>> | 90% | 47,442 psi | 76% | 2884 fps | 95.1% |
| IMR 4831 | <<locked>> | 90% | 38,203 psi | 61% | 2766 fps | 95.8% |
| IMR 4895 | <<locked>> | 80% | 40,857 psi | 66% | 2808 fps | 97.8% |
| IMR 8208 XBR | <<locked>> | 80% | 46,238 psi | 74% | 2861 fps | 99.5% |
| Lovex D073.5 | <<locked>> | 80% | 52,286 psi | 84% | 2949 fps | 100% |
| Lovex D073.6 | <<locked>> | 80% | 43,250 psi | 69% | 2828 fps | 99.9% |
| Lovex S060 | <<locked>> | 80% | 44,222 psi | 71% | 2785 fps | 98.5% |
| Lovex S062 | <<locked>> | 80% | 39,305 psi | 63% | 2730 fps | 98.5% |
| Lovex S065 | <<locked>> | 88% | 41,452 psi | 66% | 2769 fps | 95.1% |
| Lovex S070 | <<locked>> | 94% | 47,427 psi | 76% | 2910 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 43,178 psi | 69% | 2799 fps | 99.2% |
| Norma 202 | <<locked>> | 80% | 43,308 psi | 69% | 2808 fps | 100% |
| Norma 203B | <<locked>> | 80% | 39,320 psi | 63% | 2762 fps | 97.4% |
| Norma URP | <<locked>> | 88% | 37,202 psi | 60% | 2756 fps | 95.2% |
| Ramshot Big Game | <<locked>> | 80% | 38,769 psi | 62% | 2772 fps | 97% |
| Ramshot Hunter | <<locked>> | 94% | 44,237 psi | 71% | 2913 fps | 95.4% |
| Ramshot TAC | <<locked>> | 80% | 45,963 psi | 74% | 2854 fps | 96.6% |
| Ramshot Wild Boar | <<locked>> | 80% | 45,513 psi | 73% | 2881 fps | 98.6% |
| Ramshot X-Terminator | <<locked>> | 80% | 49,893 psi | 80% | 2910 fps | 99.2% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,629 psi | 43% | 1719 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 51,677 psi | 83% | 2949 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 86% | 46,340 psi | 74% | 2871 fps | 95.7% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 41,814 psi | 67% | 2881 fps | 97.4% |
| ReloadSwiss RS 60 | 45.5 gr | 80% | 34,113 psi | 55% | 2733 fps | 98.5% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 39,305 psi | 63% | 2828 fps | 95.7% |
| ReloadSwiss RS 70 | <<locked>> | 92% | 42,279 psi | 68% | 2904 fps | 95.8% |
| Rottweil R 901 | <<locked>> | 80% | 47,123 psi | 76% | 2848 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 41,089 psi | 66% | 2746 fps | 98.8% |
| Rottweil R 903 | <<locked>> | 80% | 34,519 psi | 55% | 2651 fps | 96.6% |
| Rottweil R 907 | <<locked>> | 94% | 51,721 psi | 83% | 2959 fps | 95.6% |
| Shooters World Long Rifle | <<locked>> | 88% | 41,452 psi | 66% | 2769 fps | 95.1% |
| Shooters World Match Rifle | <<locked>> | 80% | 43,250 psi | 69% | 2828 fps | 99.9% |
| Shooters World Precision | <<locked>> | 80% | 39,305 psi | 63% | 2730 fps | 98.5% |
| Shooters World SW4350 | <<locked>> | 94% | 47,427 psi | 76% | 2910 fps | 95.5% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 35,534 psi | 57% | 2700 fps | 96% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 44,324 psi | 71% | 2828 fps | 96.7% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 42,670 psi | 68% | 2815 fps | 98.1% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 44,541 psi | 71% | 2756 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 36,999 psi | 59% | 2612 fps | 99.9% |
| SNPE Vectan Tubal 7000 | <<locked>> | 92% | 46,760 psi | 75% | 2825 fps | 95.1% |
| Somchem S321 | <<locked>> | 80% | 50,111 psi | 80% | 2946 fps | 99.9% |
| Somchem S335 | <<locked>> | 80% | 44,121 psi | 71% | 2756 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 44,193 psi | 71% | 2831 fps | 98.4% |
| Somchem S355 | <<locked>> | 80% | 35,360 psi | 57% | 2657 fps | 96.7% |
| Somchem S365 | <<locked>> | 84% | 29,225 psi | 47% | 2582 fps | 95.5% |
| Vihtavuori N130 | <<locked>> | 80% | 50,227 psi | 81% | 2825 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 44,817 psi | 72% | 2753 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 40,466 psi | 65% | 2736 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 41,162 psi | 66% | 2743 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 33,649 psi | 54% | 2592 fps | 97.5% |
| Vihtavuori N160 | <<locked>> | 88% | 38,914 psi | 62% | 2759 fps | 95.7% |
| Vihtavuori N530 | <<locked>> | 80% | 46,166 psi | 74% | 2854 fps | 99.5% |
| Vihtavuori N540 | <<locked>> | 80% | 39,682 psi | 64% | 2726 fps | 99.8% |
| Vihtavuori N550 | <<locked>> | 88% | 38,189 psi | 61% | 2756 fps | 95.2% |
| Vihtavuori N555 | <<locked>> | 96% | 36,637 psi | 59% | 2792 fps | 95.9% |
| Winchester 6.5 StaBALL | <<locked>> | 82% | 31,908 psi | 51% | 2559 fps | 95.3% |
| Winchester 748 | <<locked>> | 80% | 45,919 psi | 74% | 2904 fps | 99.8% |
| Winchester 760 | <<locked>> | 94% | 48,515 psi | 78% | 2992 fps | 95.6% |
| Winchester StaBALL HD | <<locked>> | 98% | 32,140 psi | 52% | 2730 fps | 95.4% |
| Winchester StaBALL Match | <<locked>> | 80% | 42,047 psi | 67% | 2815 fps | 98.5% |
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 98 powders for .270 Win. loaded with the .277 | 120gr | Barnes BND SPIT-FIRE. Alliant Reloder-17 delivers the highest muzzle velocity at 3,166 fps; across all powders the maximum-charge window runs from 1,877 fps to 3,166 fps. Accurate 4350 gives the best case fill at 100 %, and 98 of the 98 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (430 MPa), the top charges use 55–90 %, leaving at least 10 % headroom. The 120.0 gr projectile in 0.277" calls for a 1:9.5 twist; slower twists will usually not stabilise this weight. Accurate 4350, Alliant Reloder-16, Alliant Reloder-23 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 Power Pro 2000-MR, ReloadSwiss RS 60, Alliant Reloder-17 rank at the top here: for .270 Win. with the .277 | 120gr | Barnes BND SPIT-FIRE 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.