Load Specifications
Bullet:.308 | 150gr | Hornady GMX
Bullet Manufacturer:Hornady
Bullet Weight:150 gr
Bullet Diameter:0.308"
Bullet Length:<<locked>>
Caliber:.308 Norma Mag. load data
Case Length (l3):2.559"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:86.5 Grains of Water
Primer Size:Large Rifle Magnum (LRM)
Barrel Length:24"
Max. allowed Pressure:63,817 psi
Recommended Twist Rate:1:11.5
Load data in caliber .308 Norma Mag. with .308 | 150gr | Hornady GMX bullet and 95 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.
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 2015 | <<locked>> | 84% | 55,825 psi | 87% | 2953 fps | 100% |
| Accurate 2495 | <<locked>> | 88% | 54,288 psi | 85% | 2969 fps | 100% |
| Accurate 2520 | <<locked>> | 84% | 56,405 psi | 88% | 3045 fps | 100% |
| Accurate 2700 | <<locked>> | 90% | 57,435 psi | 90% | 3025 fps | 97.1% |
| Accurate 4064 | <<locked>> | 90% | 54,302 psi | 85% | 3018 fps | 100% |
| Accurate 4350 | <<locked>> | 98% | 54,723 psi | 86% | 3107 fps | 99.4% |
| ADI AR 2206H | <<locked>> | 86% | 54,998 psi | 86% | 3054 fps | 99.9% |
| ADI AR 2208 | <<locked>> | 92% | 56,188 psi | 88% | 3058 fps | 99.8% |
| ADI Benchmark 8208 | <<locked>> | 86% | 57,537 psi | 90% | 3058 fps | 100% |
| Alliant AR-Comp | <<locked>> | 84% | 54,926 psi | 86% | 2982 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 88% | 54,955 psi | 86% | 3179 fps | 99.8% |
| Alliant Reloder- TS 15.5 | <<locked>> | 92% | 56,391 psi | 88% | 3081 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 90% | 56,782 psi | 89% | 3100 fps | 99.8% |
| Alliant Reloder-16ᴾ | <<locked>> | 100% | 56,101 psi | 88% | 3169 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 96% | 57,696 psi | 90% | 3212 fps | 100% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 39,943 psi | 63% | 2874 fps | 98.5% |
| Alliant Reloder-26ᴾ | <<locked>> | 100% | 45,049 psi | 71% | 3051 fps | 97.9% |
| Baschieri & Pellagri 107 | <<locked>> | 86% | 55,100 psi | 86% | 3071 fps | 99.5% |
| Bofors RP3 | <<locked>> | 92% | 56,913 psi | 89% | 3094 fps | 100% |
| Bofors RP7 | <<locked>> | 96% | 57,058 psi | 89% | 3064 fps | 97.3% |
| Hodgdon Benchmark | <<locked>> | 84% | 55,637 psi | 87% | 2989 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 86% | 57,130 psi | 90% | 3087 fps | 100% |
| Hodgdon CFE223 | <<locked>> | 82% | 55,593 psi | 87% | 3140 fps | 99.8% |
| Hodgdon H380 | <<locked>> | 90% | 54,259 psi | 85% | 3051 fps | 99.1% |
| Hodgdon H414 | <<locked>> | 96% | 54,215 psi | 85% | 3104 fps | 97.5% |
| Hodgdon H4350 | <<locked>> | 94% | 54,650 psi | 86% | 3064 fps | 96.2% |
| Hodgdon H4895 | <<locked>> | 86% | 55,608 psi | 87% | 3068 fps | 100% |
| Hodgdon Hybrid 100Vᴾ | <<locked>> | 100% | 52,199 psi | 82% | 3035 fps | 99.9% |
| Hodgdon LEVERevolution | <<locked>> | 88% | 55,463 psi | 87% | 3104 fps | 100% |
| Hodgdon Superformance | <<locked>> | 96% | 54,868 psi | 86% | 3140 fps | 97.2% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 35,404 psi | 55% | 1890 fps | 100% |
| Hodgdon VARGET | <<locked>> | 88% | 56,971 psi | 89% | 3071 fps | 100% |
| IMR 3031 | <<locked>> | 86% | 55,753 psi | 87% | 3051 fps | 100% |
| IMR 4064 | <<locked>> | 90% | 55,738 psi | 87% | 3041 fps | 99.8% |
| IMR 4166 Enduron | <<locked>> | 88% | 55,550 psi | 87% | 3015 fps | 97.6% |
| IMR 4350ᴾ | <<locked>> | 100% | 57,435 psi | 90% | 3087 fps | 97.4% |
| IMR 4451 Enduron | <<locked>> | 94% | 55,434 psi | 87% | 3041 fps | 97.5% |
| IMR 4831ᴾ | <<locked>> | 100% | 55,463 psi | 87% | 3100 fps | 99.6% |
| IMR 4895 | <<locked>> | 88% | 54,636 psi | 86% | 3077 fps | 99.9% |
| IMR 8208 XBR | <<locked>> | 86% | 57,537 psi | 90% | 3058 fps | 100% |
| Lovex D073.6 | <<locked>> | 86% | 54,650 psi | 86% | 3028 fps | 100% |
| Lovex S060 | <<locked>> | 86% | 54,621 psi | 86% | 2982 fps | 99.9% |
| Lovex S062 | <<locked>> | 90% | 55,361 psi | 87% | 3035 fps | 100% |
| Lovex S065 | <<locked>> | 96% | 54,607 psi | 86% | 3031 fps | 98.6% |
| Lovex S070 | <<locked>> | 98% | 55,796 psi | 87% | 3071 fps | 97.9% |
| Norma 201 | <<locked>> | 88% | 57,188 psi | 90% | 3051 fps | 100% |
| Norma 202 | <<locked>> | 86% | 54,201 psi | 85% | 2999 fps | 100% |
| Norma 203B | <<locked>> | 90% | 55,956 psi | 88% | 3087 fps | 99.9% |
| Norma URPᴾ | <<locked>> | 100% | 57,682 psi | 90% | 3153 fps | 99.7% |
| Ramshot Big Game | <<locked>> | 90% | 56,898 psi | 89% | 3114 fps | 99.9% |
| Ramshot Hunterᴾ | <<locked>> | 100% | 56,478 psi | 89% | 3146 fps | 98.6% |
| Ramshot TAC | <<locked>> | 84% | 54,288 psi | 85% | 3022 fps | 98.7% |
| Ramshot Wild Boar | <<locked>> | 86% | 57,711 psi | 90% | 3097 fps | 100% |
| Ramshot X-Terminator | <<locked>> | 82% | 54,882 psi | 86% | 3005 fps | 99.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 35,723 psi | 56% | 1932 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 82% | 56,840 psi | 89% | 3035 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 90% | 54,462 psi | 85% | 3031 fps | 98% |
| ReloadSwiss RS 52 | <<locked>> | 88% | 57,595 psi | 90% | 3176 fps | 99.9% |
| ReloadSwiss RS 60 | <<locked>> | 94% | 57,261 psi | 90% | 3209 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 98% | 54,665 psi | 86% | 3130 fps | 99.3% |
| ReloadSwiss RS 70 | <<locked>> | 98% | 54,288 psi | 85% | 3159 fps | 99.1% |
| Rottweil R 901 | <<locked>> | 86% | 57,725 psi | 90% | 3031 fps | 100% |
| Rottweil R 902 | <<locked>> | 90% | 57,711 psi | 90% | 3051 fps | 100% |
| Rottweil R 903 | <<locked>> | 94% | 56,768 psi | 89% | 3084 fps | 100% |
| Rottweil R 907 | <<locked>> | 96% | 57,058 psi | 89% | 3064 fps | 97.3% |
| Shooters World Long Rifle | <<locked>> | 96% | 54,607 psi | 86% | 3031 fps | 98.6% |
| Shooters World Match Rifle | <<locked>> | 86% | 54,650 psi | 86% | 3028 fps | 100% |
| Shooters World Precision | <<locked>> | 90% | 55,361 psi | 87% | 3035 fps | 100% |
| Shooters World SW4350 | <<locked>> | 98% | 55,796 psi | 87% | 3071 fps | 97.9% |
| SNPE Vectan SP 11 | <<locked>> | 92% | 55,100 psi | 86% | 3094 fps | 99.9% |
| SNPE Vectan SP 7 | <<locked>> | 86% | 56,463 psi | 88% | 3058 fps | 99.2% |
| SNPE Vectan SP 9 | <<locked>> | 88% | 57,130 psi | 90% | 3081 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 86% | 55,100 psi | 86% | 2936 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 92% | 55,593 psi | 87% | 2936 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 96% | 55,201 psi | 87% | 2986 fps | 97.5% |
| Somchem S321 | <<locked>> | 82% | 55,274 psi | 87% | 3038 fps | 100% |
| Somchem S335 | <<locked>> | 86% | 54,520 psi | 85% | 2933 fps | 100% |
| Somchem S341 | <<locked>> | 86% | 56,159 psi | 88% | 3048 fps | 99.9% |
| Somchem S355 | <<locked>> | 94% | 57,043 psi | 89% | 3081 fps | 100% |
| Somchem S365ᴾ | <<locked>> | 100% | 51,851 psi | 81% | 3094 fps | 100% |
| Vihtavuori N130 | <<locked>> | 82% | 54,868 psi | 86% | 2900 fps | 100% |
| Vihtavuori N133 | <<locked>> | 86% | 55,405 psi | 87% | 2923 fps | 100% |
| Vihtavuori N135 | <<locked>> | 90% | 57,580 psi | 90% | 3012 fps | 100% |
| Vihtavuori N140 | <<locked>> | 88% | 54,795 psi | 86% | 2979 fps | 100% |
| Vihtavuori N150 | <<locked>> | 94% | 55,042 psi | 86% | 3009 fps | 100% |
| Vihtavuori N160 | <<locked>> | 98% | 56,478 psi | 89% | 3091 fps | 99.5% |
| Vihtavuori N530 | <<locked>> | 84% | 54,346 psi | 85% | 3002 fps | 100% |
| Vihtavuori N540 | <<locked>> | 90% | 56,739 psi | 89% | 3025 fps | 100% |
| Vihtavuori N550 | <<locked>> | 98% | 55,448 psi | 87% | 3094 fps | 99.3% |
| Vihtavuori N555ᴾ | <<locked>> | 100% | 43,845 psi | 69% | 2956 fps | 98.4% |
| Winchester 6.5 StaBALL | <<locked>> | 98% | 56,942 psi | 89% | 3071 fps | 100% |
| Winchester 748 | <<locked>> | 84% | 54,650 psi | 86% | 3054 fps | 100% |
| Winchester 760 | <<locked>> | 96% | 54,215 psi | 85% | 3104 fps | 97.5% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 35,694 psi | 56% | 2867 fps | 98.3% |
| Winchester StaBALL Match | <<locked>> | 88% | 57,334 psi | 90% | 3091 fps | 100% |
Start Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2015 | <<locked>> | 80% | 49,124 psi | 77% | 2854 fps | 100% |
| Accurate 2495 | <<locked>> | 80% | 41,408 psi | 65% | 2759 fps | 100% |
| Accurate 2520 | <<locked>> | 80% | 49,168 psi | 77% | 2933 fps | 100% |
| Accurate 2700 | <<locked>> | 86% | 50,270 psi | 79% | 2907 fps | 95.7% |
| Accurate 4064 | <<locked>> | 80% | 39,189 psi | 61% | 2753 fps | 100% |
| Accurate 4350 | <<locked>> | 86% | 35,607 psi | 56% | 2730 fps | 95.3% |
| ADI AR 2206H | <<locked>> | 80% | 45,324 psi | 71% | 2881 fps | 99% |
| ADI AR 2208 | <<locked>> | 80% | 38,580 psi | 60% | 2720 fps | 97% |
| ADI Benchmark 8208 | <<locked>> | 80% | 47,485 psi | 74% | 2894 fps | 99.8% |
| Alliant AR-Comp | <<locked>> | 80% | 48,022 psi | 75% | 2881 fps | 100% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 41,481 psi | 65% | 2913 fps | 97.6% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 38,130 psi | 60% | 2740 fps | 98.3% |
| Alliant Reloder-15 | <<locked>> | 80% | 40,988 psi | 64% | 2808 fps | 97.8% |
| Alliant Reloder-16 | <<locked>> | 86% | 35,766 psi | 56% | 2746 fps | 95.5% |
| Alliant Reloder-17 | <<locked>> | 80% | 32,851 psi | 51% | 2694 fps | 96.2% |
| Alliant Reloder-23 | <<locked>> | 92% | 30,864 psi | 48% | 2635 fps | 95.1% |
| Alliant Reloder-26 | <<locked>> | 96% | 38,899 psi | 61% | 2907 fps | 95.9% |
| Baschieri & Pellagri 107 | <<locked>> | 80% | 44,846 psi | 70% | 2887 fps | 98.1% |
| Bofors RP3 | <<locked>> | 80% | 37,681 psi | 59% | 2740 fps | 98.3% |
| Bofors RP7 | <<locked>> | 90% | 46,934 psi | 74% | 2887 fps | 95.1% |
| Hodgdon Benchmark | <<locked>> | 80% | 49,269 psi | 77% | 2887 fps | 100% |
| Hodgdon BL-C2 | <<locked>> | 80% | 46,586 psi | 73% | 2917 fps | 99.9% |
| Hodgdon CFE223 | <<locked>> | 80% | 51,779 psi | 81% | 3077 fps | 99.5% |
| Hodgdon H380 | <<locked>> | 80% | 38,566 psi | 60% | 2743 fps | 95.8% |
| Hodgdon H414 | <<locked>> | 90% | 44,208 psi | 69% | 2917 fps | 95.1% |
| Hodgdon H4350 | <<locked>> | 92% | 51,242 psi | 80% | 3005 fps | 95.4% |
| Hodgdon H4895 | <<locked>> | 80% | 45,774 psi | 72% | 2897 fps | 99.4% |
| Hodgdon Hybrid 100V | <<locked>> | 84% | 30,748 psi | 48% | 2579 fps | 95.3% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 41,930 psi | 66% | 2861 fps | 99.1% |
| Hodgdon Superformance | <<locked>> | 92% | 47,311 psi | 74% | 2999 fps | 95.4% |
| Hodgdon TrailBoss | <<locked>> | 80% | 26,324 psi | 41% | 1690 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 43,947 psi | 69% | 2844 fps | 99.1% |
| IMR 3031 | <<locked>> | 80% | 45,527 psi | 71% | 2890 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 40,509 psi | 63% | 2759 fps | 97.7% |
| IMR 4166 Enduron | <<locked>> | 82% | 45,905 psi | 72% | 2841 fps | 95.4% |
| IMR 4350 | <<locked>> | 94% | 47,558 psi | 75% | 2920 fps | 95.3% |
| IMR 4451 Enduron | <<locked>> | 88% | 46,050 psi | 72% | 2871 fps | 95.4% |
| IMR 4831 | <<locked>> | 86% | 34,490 psi | 54% | 2684 fps | 95% |
| IMR 4895 | <<locked>> | 80% | 41,989 psi | 66% | 2844 fps | 98.5% |
| IMR 8208 XBR | <<locked>> | 80% | 47,485 psi | 74% | 2894 fps | 99.8% |
| Lovex D073.6 | <<locked>> | 80% | 44,498 psi | 70% | 2858 fps | 100% |
| Lovex S060 | <<locked>> | 80% | 45,324 psi | 71% | 2818 fps | 99% |
| Lovex S062 | <<locked>> | 80% | 40,292 psi | 63% | 2759 fps | 99.1% |
| Lovex S065 | <<locked>> | 86% | 39,943 psi | 63% | 2749 fps | 95.2% |
| Lovex S070 | <<locked>> | 92% | 45,977 psi | 72% | 2894 fps | 95.8% |
| Norma 201 | <<locked>> | 80% | 44,251 psi | 69% | 2831 fps | 99.6% |
| Norma 202 | <<locked>> | 80% | 44,715 psi | 70% | 2841 fps | 100% |
| Norma 203B | <<locked>> | 80% | 40,335 psi | 63% | 2795 fps | 98.1% |
| Norma URP | <<locked>> | 86% | 36,100 psi | 57% | 2736 fps | 95.4% |
| Ramshot Big Game | <<locked>> | 80% | 40,190 psi | 63% | 2812 fps | 97.9% |
| Ramshot Hunter | <<locked>> | 92% | 43,047 psi | 67% | 2900 fps | 95.7% |
| Ramshot TAC | <<locked>> | 80% | 47,514 psi | 74% | 2897 fps | 97.5% |
| Ramshot Wild Boar | <<locked>> | 80% | 47,007 psi | 74% | 2917 fps | 99.2% |
| Ramshot X-Terminator | <<locked>> | 80% | 51,358 psi | 80% | 2946 fps | 99.6% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 26,513 psi | 42% | 1729 fps | 100% |
| ReloadSwiss RS 40 | <<locked>> | 80% | 53,287 psi | 84% | 2982 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 82% | 41,771 psi | 65% | 2789 fps | 95% |
| ReloadSwiss RS 52 | <<locked>> | 80% | 43,366 psi | 68% | 2920 fps | 98.2% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 35,056 psi | 55% | 2769 fps | 99.2% |
| ReloadSwiss RS 62 | <<locked>> | 88% | 38,261 psi | 60% | 2815 fps | 95.9% |
| ReloadSwiss RS 70 | <<locked>> | 88% | 38,159 psi | 60% | 2818 fps | 95% |
| Rottweil R 901 | <<locked>> | 80% | 48,066 psi | 75% | 2877 fps | 100% |
| Rottweil R 902 | <<locked>> | 80% | 42,047 psi | 66% | 2779 fps | 99.3% |
| Rottweil R 903 | <<locked>> | 80% | 35,404 psi | 55% | 2680 fps | 97.4% |
| Rottweil R 907 | <<locked>> | 90% | 46,934 psi | 74% | 2887 fps | 95.1% |
| Shooters World Long Rifle | <<locked>> | 86% | 39,943 psi | 63% | 2749 fps | 95.2% |
| Shooters World Match Rifle | <<locked>> | 80% | 44,498 psi | 70% | 2858 fps | 100% |
| Shooters World Precision | <<locked>> | 80% | 40,292 psi | 63% | 2759 fps | 99.1% |
| Shooters World SW4350 | <<locked>> | 92% | 45,977 psi | 72% | 2894 fps | 95.8% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 36,550 psi | 57% | 2733 fps | 96.9% |
| SNPE Vectan SP 7 | <<locked>> | 80% | 45,774 psi | 72% | 2871 fps | 97.6% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 43,845 psi | 69% | 2848 fps | 98.7% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 45,745 psi | 72% | 2789 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 38,058 psi | 60% | 2641 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 44,976 psi | 70% | 2805 fps | 95.2% |
| Somchem S321 | <<locked>> | 80% | 51,619 psi | 81% | 2979 fps | 100% |
| Somchem S335 | <<locked>> | 80% | 45,281 psi | 71% | 2785 fps | 100% |
| Somchem S341 | <<locked>> | 80% | 45,614 psi | 71% | 2867 fps | 99% |
| Somchem S355 | <<locked>> | 80% | 36,289 psi | 57% | 2690 fps | 97.5% |
| Somchem S365 | <<locked>> | 82% | 28,036 psi | 44% | 2552 fps | 95.6% |
| Vihtavuori N130 | <<locked>> | 80% | 51,648 psi | 81% | 2854 fps | 100% |
| Vihtavuori N133 | <<locked>> | 80% | 46,166 psi | 72% | 2782 fps | 100% |
| Vihtavuori N135 | <<locked>> | 80% | 41,771 psi | 65% | 2766 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 42,366 psi | 66% | 2772 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 34,548 psi | 54% | 2621 fps | 98.2% |
| Vihtavuori N160 | <<locked>> | 86% | 37,652 psi | 59% | 2740 fps | 95.9% |
| Vihtavuori N530 | <<locked>> | 80% | 47,601 psi | 75% | 2890 fps | 99.8% |
| Vihtavuori N540 | <<locked>> | 80% | 40,756 psi | 64% | 2756 fps | 100% |
| Vihtavuori N550 | <<locked>> | 86% | 37,028 psi | 58% | 2736 fps | 95.4% |
| Vihtavuori N555 | <<locked>> | 92% | 33,431 psi | 52% | 2717 fps | 95.2% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 30,690 psi | 48% | 2536 fps | 95.5% |
| Winchester 748 | <<locked>> | 80% | 47,442 psi | 74% | 2936 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 44,208 psi | 69% | 2917 fps | 95.1% |
| Winchester StaBALL HD | <<locked>> | 96% | 31,169 psi | 49% | 2720 fps | 95.8% |
| Winchester StaBALL Match | <<locked>> | 80% | 43,569 psi | 68% | 2854 fps | 99.1% |
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 95 powders for .308 Norma Mag. loaded with the .308 | 150gr | Hornady GMX. Alliant Reloder-17 delivers the highest muzzle velocity at 3,212 fps; across all powders the maximum-charge window runs from 1,890 fps to 3,212 fps. Alliant Reloder-16 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 (440 MPa), the top charges use 55–90 %, 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. Alliant Reloder-16, Alliant Reloder-23, Alliant Reloder-26 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.