Load Specifications
Bullet:.338 | 185gr | Hornady ECX
Bullet Manufacturer:Hornady
Bullet Weight:185 gr
Bullet Diameter:0.338"
Bullet Length:<<locked>>
Case Length (l3):2.724"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:124.89 Grains of Water
Primer Size:Large Rifle Magnum (LRM)
Barrel Length:27"
Max. allowed Pressure:69,618 psi
Recommended Twist Rate:1:14.5
Load data in caliber .338 Lapua Mag. Ackley Improved with .338 | 185gr | Hornady ECX bullet and 105 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are IMR 7828 SSC, Vihtavuori N560 and Norma MRP.
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: 27"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 82% | 62,018 psi | 89% | 3130 fps | 100% |
| Accurate 2700 | <<locked>> | 84% | 62,758 psi | 90% | 3225 fps | 99.9% |
| Accurate 3100 | <<locked>> | 98% | 59,437 psi | 85% | 3228 fps | 100% |
| Accurate 4064 | <<locked>> | 84% | 62,555 psi | 90% | 3192 fps | 100% |
| Accurate 4350 | <<locked>> | 90% | 61,017 psi | 88% | 3278 fps | 100% |
| Accurate High Country | <<locked>> | 96% | 61,192 psi | 88% | 3402 fps | 99.2% |
| Accurate MAGPRO | <<locked>> | 98% | 62,468 psi | 90% | 3402 fps | 98.6% |
| ADI APS 450 | <<locked>> | 84% | 62,859 psi | 90% | 2556 fps | 100% |
| ADI AR 2208 | <<locked>> | 86% | 61,728 psi | 89% | 3232 fps | 100% |
| ADI AR 2209 | <<locked>> | 96% | 61,786 psi | 89% | 3337 fps | 99.7% |
| ADI AR 2213 | <<locked>> | 98% | 59,553 psi | 86% | 3340 fps | 98.9% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 46,441 psi | 67% | 3084 fps | 96.7% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 41,379 psi | 59% | 3038 fps | 98.4% |
| Alliant Power Pro 2000-MR | <<locked>> | 82% | 62,975 psi | 90% | 3383 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 62,018 psi | 89% | 3330 fps | 99.7% |
| Alliant Power Pro Varmint | <<locked>> | 96% | 62,018 psi | 89% | 3330 fps | 99.7% |
| Alliant Reloder- TS 15.5 | <<locked>> | 84% | 59,422 psi | 85% | 3205 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 82% | 59,437 psi | 85% | 3232 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 92% | 61,424 psi | 88% | 3333 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 86% | 59,190 psi | 85% | 3297 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 96% | 61,163 psi | 88% | 3320 fps | 99.6% |
| Alliant Reloder-22 | <<locked>> | 98% | 59,263 psi | 85% | 3333 fps | 99.6% |
| Alliant Reloder-23ᴾ | <<locked>> | 100% | 60,075 psi | 86% | 3294 fps | 100% |
| Alliant Reloder-25ᴾ | <<locked>> | 100% | 52,040 psi | 75% | 3241 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 96% | 61,453 psi | 88% | 3402 fps | 100% |
| Baschieri & Pellagri 109ᴾ | <<locked>> | 100% | 61,627 psi | 89% | 3287 fps | 96.8% |
| Bofors RP15ᴾ | <<locked>> | 100% | 57,986 psi | 83% | 3310 fps | 99.4% |
| Bofors RP3 | <<locked>> | 84% | 60,843 psi | 87% | 3225 fps | 100% |
| Bofors RP30ᴾ | <<locked>> | 100% | 48,066 psi | 69% | 3166 fps | 97.6% |
| Bofors RP5 | <<locked>> | 98% | 59,263 psi | 85% | 3333 fps | 99.6% |
| Bofors RP7 | <<locked>> | 88% | 59,640 psi | 86% | 3222 fps | 99.8% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 51,198 psi | 74% | 3182 fps | 98.4% |
| Hodgdon H380 | <<locked>> | 84% | 60,959 psi | 88% | 3248 fps | 100% |
| Hodgdon H414 | <<locked>> | 90% | 62,772 psi | 90% | 3337 fps | 100% |
| Hodgdon H4350 | <<locked>> | 88% | 61,525 psi | 88% | 3291 fps | 99.7% |
| Hodgdon H4831 | <<locked>> | 96% | 59,567 psi | 86% | 3271 fps | 98.4% |
| Hodgdon H4831 SC | <<locked>> | 98% | 62,468 psi | 90% | 3314 fps | 98.7% |
| Hodgdon Hybrid 100V | <<locked>> | 94% | 61,888 psi | 89% | 3241 fps | 100% |
| Hodgdon LEVERevolution | <<locked>> | 82% | 62,569 psi | 90% | 3278 fps | 100% |
| Hodgdon Retumboᴾ | <<locked>> | 100% | 50,995 psi | 73% | 3304 fps | 99.4% |
| Hodgdon Superformance | <<locked>> | 88% | 59,712 psi | 86% | 3317 fps | 99.9% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 36,767 psi | 53% | 2034 fps | 100% |
| Hodgdon VARGET | <<locked>> | 82% | 62,047 psi | 89% | 3235 fps | 100% |
| IMR 4064 | <<locked>> | 84% | 61,105 psi | 88% | 3212 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 82% | 59,886 psi | 86% | 3205 fps | 99.9% |
| IMR 4350 | <<locked>> | 92% | 61,177 psi | 88% | 3255 fps | 99.9% |
| IMR 4451 Enduron | <<locked>> | 88% | 61,119 psi | 88% | 3245 fps | 100% |
| IMR 4831 | <<locked>> | 92% | 61,076 psi | 88% | 3261 fps | 100% |
| IMR 4895 | <<locked>> | 82% | 60,988 psi | 88% | 3261 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 96% | 60,394 psi | 87% | 3251 fps | 98.6% |
| IMR 7828 SSCᴾ | <<locked>> | 100% | 61,017 psi | 88% | 3376 fps | 99.2% |
| Lovex S060 | <<locked>> | 82% | 62,047 psi | 89% | 3189 fps | 100% |
| Lovex S062 | <<locked>> | 84% | 61,540 psi | 88% | 3202 fps | 100% |
| Lovex S065 | <<locked>> | 90% | 61,685 psi | 89% | 3241 fps | 100% |
| Lovex S070 | <<locked>> | 90% | 59,683 psi | 86% | 3235 fps | 100% |
| Lovex S071ᴾ | <<locked>> | 100% | 52,823 psi | 76% | 3130 fps | 99.9% |
| Norma 201 | <<locked>> | 82% | 62,700 psi | 90% | 3215 fps | 100% |
| Norma 203B | <<locked>> | 84% | 62,685 psi | 90% | 3268 fps | 100% |
| Norma 204 | <<locked>> | 92% | 62,845 psi | 90% | 3327 fps | 99.7% |
| Norma 217ᴾ | <<locked>> | 100% | 36,753 psi | 53% | 2949 fps | 96.3% |
| Norma MRP | <<locked>> | 96% | 59,277 psi | 85% | 3360 fps | 100% |
| Norma URP | <<locked>> | 92% | 62,990 psi | 90% | 3314 fps | 100% |
| Ramshot Big Game | <<locked>> | 82% | 60,147 psi | 86% | 3241 fps | 100% |
| Ramshot Grandᴾ | <<locked>> | 100% | 62,366 psi | 90% | 3399 fps | 99.5% |
| Ramshot Hunter | <<locked>> | 92% | 61,975 psi | 89% | 3320 fps | 100% |
| Ramshot Magnumᴾ | <<locked>> | 100% | 56,362 psi | 81% | 3258 fps | 99.8% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 37,521 psi | 54% | 2080 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 84% | 60,481 psi | 87% | 3232 fps | 100% |
| ReloadSwiss RS 60 | <<locked>> | 84% | 58,537 psi | 84% | 3284 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 90% | 61,003 psi | 88% | 3301 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 90% | 59,393 psi | 85% | 3333 fps | 100% |
| ReloadSwiss RS 76ᴾ | <<locked>> | 100% | 51,721 psi | 74% | 3301 fps | 99.9% |
| Rottweil R 902 | <<locked>> | 82% | 59,596 psi | 86% | 3159 fps | 100% |
| Rottweil R 903 | <<locked>> | 86% | 60,872 psi | 87% | 3219 fps | 100% |
| Rottweil R 904 | <<locked>> | 94% | 59,146 psi | 85% | 3241 fps | 98.8% |
| Rottweil R 905 | <<locked>> | 96% | 60,640 psi | 87% | 3307 fps | 99.7% |
| Rottweil R 907 | <<locked>> | 88% | 59,640 psi | 86% | 3222 fps | 99.8% |
| Shooters World Long Rifle | <<locked>> | 90% | 61,685 psi | 89% | 3241 fps | 100% |
| Shooters World Precision | <<locked>> | 84% | 61,540 psi | 88% | 3202 fps | 100% |
| Shooters World SW4350 | <<locked>> | 90% | 59,683 psi | 86% | 3235 fps | 100% |
| SNPE Vectan SP 11 | <<locked>> | 86% | 62,801 psi | 90% | 3284 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 82% | 62,801 psi | 90% | 3251 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 82% | 62,888 psi | 90% | 3127 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 86% | 60,698 psi | 87% | 3077 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 90% | 61,366 psi | 88% | 3192 fps | 100% |
| SNPE Vectan Tubal 8000 | <<locked>> | 96% | 60,162 psi | 86% | 3304 fps | 99.6% |
| Somchem S335 | <<locked>> | 82% | 62,758 psi | 90% | 3120 fps | 100% |
| Somchem S355 | <<locked>> | 86% | 60,379 psi | 87% | 3212 fps | 100% |
| Somchem S361 | <<locked>> | 94% | 61,192 psi | 88% | 3228 fps | 98.5% |
| Somchem S365 | <<locked>> | 92% | 59,379 psi | 85% | 3255 fps | 100% |
| Somchem S385 | <<locked>> | 96% | 61,192 psi | 88% | 3274 fps | 99.9% |
| Vihtavuori N135 | <<locked>> | 82% | 60,394 psi | 87% | 3110 fps | 100% |
| Vihtavuori N140 | <<locked>> | 82% | 60,568 psi | 87% | 3127 fps | 100% |
| Vihtavuori N150 | <<locked>> | 88% | 62,018 psi | 89% | 3179 fps | 100% |
| Vihtavuori N160 | <<locked>> | 90% | 61,134 psi | 88% | 3248 fps | 100% |
| Vihtavuori N165ᴾ | <<locked>> | 100% | 60,800 psi | 87% | 3248 fps | 99.8% |
| Vihtavuori N540 | <<locked>> | 84% | 62,642 psi | 90% | 3176 fps | 100% |
| Vihtavuori N550 | <<locked>> | 90% | 60,220 psi | 87% | 3255 fps | 100% |
| Vihtavuori N555 | <<locked>> | 98% | 62,540 psi | 90% | 3323 fps | 100% |
| Vihtavuori N560 | <<locked>> | 96% | 59,132 psi | 85% | 3353 fps | 98.6% |
| Vihtavuori N565ᴾ | <<locked>> | 100% | 54,737 psi | 79% | 3255 fps | 98.1% |
| Winchester 6.5 StaBALL | <<locked>> | 90% | 61,163 psi | 88% | 3199 fps | 100% |
| Winchester 760 | <<locked>> | 90% | 62,975 psi | 90% | 3340 fps | 100% |
| Winchester StaBALL HDᴾ | <<locked>> | 100% | 57,740 psi | 83% | 3386 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 98% | 61,598 psi | 88% | 3274 fps | 99.6% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 27"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 2495 | <<locked>> | 80% | 58,146 psi | 84% | 3077 fps | 100% |
| Accurate 2700 | <<locked>> | 80% | 54,984 psi | 79% | 3107 fps | 99.4% |
| Accurate 3100 | <<locked>> | 80% | 32,039 psi | 46% | 2690 fps | 95.8% |
| Accurate 4064 | <<locked>> | 80% | 55,172 psi | 79% | 3094 fps | 100% |
| Accurate 4350 | <<locked>> | 80% | 43,178 psi | 62% | 2979 fps | 99.7% |
| Accurate High Country | <<locked>> | 86% | 42,888 psi | 62% | 3064 fps | 95.7% |
| Accurate MAGPRO | <<locked>> | 90% | 46,804 psi | 67% | 3127 fps | 95.4% |
| ADI APS 450 | <<locked>> | 80% | 58,726 psi | 84% | 2497 fps | 100% |
| ADI AR 2208 | <<locked>> | 80% | 51,242 psi | 74% | 3071 fps | 100% |
| ADI AR 2209 | <<locked>> | 82% | 38,580 psi | 55% | 2894 fps | 95.2% |
| ADI AR 2213 | <<locked>> | 88% | 42,177 psi | 61% | 3005 fps | 95% |
| ADI AR 2217 | <<locked>> | 98% | 43,482 psi | 62% | 3018 fps | 95.7% |
| ADI AR 2225 | <<locked>> | 94% | 33,939 psi | 49% | 2838 fps | 95.4% |
| Alliant Power Pro 2000-MR | <<locked>> | 80% | 58,581 psi | 84% | 3320 fps | 100% |
| Alliant Power Pro Varmint | <<locked>> | 82% | 38,899 psi | 56% | 2897 fps | 95.4% |
| Alliant Power Pro Varmint | <<locked>> | 82% | 38,899 psi | 56% | 2897 fps | 95.4% |
| Alliant Reloder- TS 15.5 | <<locked>> | 80% | 52,417 psi | 75% | 3100 fps | 100% |
| Alliant Reloder-15 | <<locked>> | 80% | 55,825 psi | 80% | 3176 fps | 100% |
| Alliant Reloder-16 | <<locked>> | 80% | 41,292 psi | 59% | 2986 fps | 99.8% |
| Alliant Reloder-17 | <<locked>> | 80% | 47,732 psi | 69% | 3117 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 82% | 38,522 psi | 55% | 2890 fps | 95.3% |
| Alliant Reloder-22 | <<locked>> | 86% | 39,305 psi | 56% | 2949 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 30,734 psi | 44% | 2726 fps | 98.7% |
| Alliant Reloder-25 | <<locked>> | 84% | 30,676 psi | 44% | 2736 fps | 95.8% |
| Alliant Reloder-26 | <<locked>> | 80% | 33,344 psi | 48% | 2861 fps | 97.8% |
| Baschieri & Pellagri 109 | <<locked>> | 96% | 54,302 psi | 78% | 3163 fps | 95.2% |
| Bofors RP15 | <<locked>> | 88% | 38,928 psi | 56% | 2940 fps | 95.5% |
| Bofors RP3 | <<locked>> | 80% | 53,214 psi | 76% | 3114 fps | 100% |
| Bofors RP30 | <<locked>> | 96% | 41,858 psi | 60% | 3035 fps | 95.9% |
| Bofors RP5 | <<locked>> | 86% | 39,305 psi | 56% | 2949 fps | 95.8% |
| Bofors RP7 | <<locked>> | 80% | 46,267 psi | 66% | 2989 fps | 98.3% |
| Hodgdon H1000 | <<locked>> | 94% | 41,655 psi | 60% | 2979 fps | 95.8% |
| Hodgdon H380 | <<locked>> | 80% | 53,243 psi | 76% | 3130 fps | 100% |
| Hodgdon H414 | <<locked>> | 80% | 44,817 psi | 64% | 3028 fps | 98.5% |
| Hodgdon H4350 | <<locked>> | 80% | 47,500 psi | 68% | 3048 fps | 98% |
| Hodgdon H4831 | <<locked>> | 88% | 45,223 psi | 65% | 3015 fps | 95.3% |
| Hodgdon H4831 SC | <<locked>> | 88% | 44,251 psi | 64% | 2995 fps | 95% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 38,885 psi | 56% | 2861 fps | 99.9% |
| Hodgdon LEVERevolution | <<locked>> | 80% | 58,392 psi | 84% | 3219 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 90% | 36,463 psi | 52% | 2949 fps | 95.1% |
| Hodgdon Superformance | <<locked>> | 80% | 44,295 psi | 64% | 3048 fps | 98.3% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,470 psi | 39% | 1824 fps | 100% |
| Hodgdon VARGET | <<locked>> | 80% | 58,320 psi | 84% | 3182 fps | 100% |
| IMR 4064 | <<locked>> | 80% | 53,925 psi | 77% | 3107 fps | 100% |
| IMR 4166 Enduron | <<locked>> | 80% | 56,130 psi | 81% | 3146 fps | 99.8% |
| IMR 4350 | <<locked>> | 80% | 41,742 psi | 60% | 2907 fps | 97.4% |
| IMR 4451 Enduron | <<locked>> | 80% | 47,529 psi | 68% | 3015 fps | 98.9% |
| IMR 4831 | <<locked>> | 80% | 41,118 psi | 59% | 2923 fps | 99.6% |
| IMR 4895 | <<locked>> | 80% | 57,319 psi | 82% | 3205 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 86% | 43,903 psi | 63% | 2953 fps | 95.1% |
| IMR 7828 SSC | 97.7 gr | 90% | 43,323 psi | 62% | 3045 fps | 95.5% |
| Lovex S060 | <<locked>> | 80% | 58,392 psi | 84% | 3140 fps | 100% |
| Lovex S062 | <<locked>> | 80% | 54,375 psi | 78% | 3100 fps | 100% |
| Lovex S065 | <<locked>> | 80% | 45,150 psi | 65% | 2963 fps | 99.3% |
| Lovex S070 | <<locked>> | 80% | 43,424 psi | 62% | 2946 fps | 98.4% |
| Lovex S071 | <<locked>> | 84% | 31,430 psi | 45% | 2674 fps | 95.5% |
| Norma 201 | <<locked>> | 80% | 58,929 psi | 85% | 3163 fps | 100% |
| Norma 203B | <<locked>> | 80% | 55,187 psi | 79% | 3163 fps | 100% |
| Norma 204 | <<locked>> | 80% | 41,597 psi | 60% | 2943 fps | 96.1% |
| Norma 217 | <<locked>> | 98% | 34,389 psi | 49% | 2884 fps | 95.2% |
| Norma MRP | 92.5 gr | 82% | 35,853 psi | 52% | 2894 fps | 96% |
| Norma URP | <<locked>> | 80% | 42,395 psi | 61% | 2966 fps | 99.6% |
| Ramshot Big Game | <<locked>> | 80% | 56,159 psi | 81% | 3182 fps | 100% |
| Ramshot Grand | <<locked>> | 90% | 43,250 psi | 62% | 3054 fps | 95.9% |
| Ramshot Hunter | <<locked>> | 80% | 41,350 psi | 59% | 2956 fps | 98.5% |
| Ramshot Magnum | <<locked>> | 88% | 35,868 psi | 52% | 2848 fps | 95.4% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,079 psi | 40% | 1867 fps | 100% |
| ReloadSwiss RS 50 | <<locked>> | 80% | 53,026 psi | 76% | 3114 fps | 99.8% |
| ReloadSwiss RS 60 | <<locked>> | 80% | 50,618 psi | 73% | 3169 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 43,047 psi | 62% | 2999 fps | 99.6% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 41,394 psi | 59% | 3012 fps | 99.4% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 35,940 psi | 52% | 2930 fps | 96.3% |
| Rottweil R 902 | <<locked>> | 80% | 56,217 psi | 81% | 3114 fps | 100% |
| Rottweil R 903 | <<locked>> | 80% | 50,038 psi | 72% | 3054 fps | 100% |
| Rottweil R 904 | <<locked>> | 84% | 42,743 psi | 61% | 2936 fps | 95.3% |
| Rottweil R 905 | <<locked>> | 82% | 37,710 psi | 54% | 2871 fps | 95.2% |
| Rottweil R 907 | <<locked>> | 80% | 46,267 psi | 66% | 2989 fps | 98.3% |
| Shooters World Long Rifle | <<locked>> | 80% | 45,150 psi | 65% | 2963 fps | 99.3% |
| Shooters World Precision | <<locked>> | 80% | 54,375 psi | 78% | 3100 fps | 100% |
| Shooters World SW4350 | <<locked>> | 80% | 43,424 psi | 62% | 2946 fps | 98.4% |
| SNPE Vectan SP 11 | <<locked>> | 80% | 51,474 psi | 74% | 3117 fps | 100% |
| SNPE Vectan SP 9 | <<locked>> | 80% | 58,900 psi | 85% | 3196 fps | 100% |
| SNPE Vectan Tubal 3000 | <<locked>> | 80% | 59,205 psi | 85% | 3077 fps | 100% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 50,502 psi | 73% | 2936 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 44,193 psi | 63% | 2900 fps | 98.4% |
| SNPE Vectan Tubal 8000 | <<locked>> | 82% | 37,362 psi | 54% | 2864 fps | 95% |
| Somchem S335 | <<locked>> | 80% | 59,088 psi | 85% | 3071 fps | 100% |
| Somchem S355 | <<locked>> | 80% | 50,053 psi | 72% | 3054 fps | 100% |
| Somchem S361 | <<locked>> | 86% | 46,804 psi | 67% | 2982 fps | 95.7% |
| Somchem S365 | <<locked>> | 80% | 39,218 psi | 56% | 2920 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 35,926 psi | 52% | 2792 fps | 95.5% |
| Vihtavuori N135 | <<locked>> | 80% | 56,811 psi | 82% | 3061 fps | 100% |
| Vihtavuori N140 | <<locked>> | 80% | 56,724 psi | 81% | 3074 fps | 100% |
| Vihtavuori N150 | <<locked>> | 80% | 47,863 psi | 69% | 2972 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 43,903 psi | 63% | 2963 fps | 99.7% |
| Vihtavuori N165 | <<locked>> | 86% | 37,942 psi | 55% | 2831 fps | 95.8% |
| Vihtavuori N540 | <<locked>> | 80% | 54,998 psi | 79% | 3071 fps | 100% |
| Vihtavuori N550 | <<locked>> | 80% | 43,265 psi | 62% | 2963 fps | 99.6% |
| Vihtavuori N555 | <<locked>> | 80% | 34,418 psi | 49% | 2808 fps | 98.7% |
| Vihtavuori N560 | 99.2 gr | 88% | 44,498 psi | 64% | 3077 fps | 95.4% |
| Vihtavuori N565 | <<locked>> | 94% | 44,512 psi | 64% | 3061 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 42,989 psi | 62% | 2917 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 44,976 psi | 65% | 3031 fps | 98.6% |
| Winchester StaBALL HD | <<locked>> | 80% | 27,296 psi | 39% | 2720 fps | 98.6% |
| Winchester Supreme 780 | <<locked>> | 84% | 37,739 psi | 54% | 2835 fps | 95% |
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 105 powders for .338 Lapua Mag. Ackley Improved loaded with the .338 | 185gr | Hornady ECX. Accurate High Country delivers the highest muzzle velocity at 3,402 fps; across all powders the maximum-charge window runs from 2,034 fps to 3,402 fps. ADI AR 2217 gives the best case fill at 100 %, and 105 of the 105 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (480 MPa), the top charges use 53–90 %, leaving at least 10 % headroom. The 185.0 gr projectile in 0.338" calls for a 1:14.5 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, 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. IMR 7828 SSC, Vihtavuori N560, Norma MRP rank at the top here: for .338 Lapua Mag. Ackley Improved with the .338 | 185gr | Hornady ECX 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.