The .338 Lapua Ackley Improved offers several advantages over the .338 Lapua cartridge. Our understanding is that AI (Ackley Improved) means the there will be a 40 degree shoulder.  Many of the Lapua Improvements and other Improvements for that matter are down around a 35 degree shoulder angle. The 40 degree shoulder does two things for the reloader and shooter. First in increases case capacity by 10 grains. Second, it offers an extended case life over cases with 30-35 degree shoulders. The 40 degree shoulder may have some problems feeding so many Improvements may use a 37.5 degree shoulder as a compromise. Some suggest that annealling every three shots would be a good idea with a 40 degree shoulder.

Below are some pictures submitted by a customer who is having a custom rifle chambered in .338 Lapua Ackley Improved being built by Chris Brown, owner/operator of Long Range Customs, in Post Falls Idaho. Chris fireforms the .338 Lapua brass. His email is This email address is being protected from spambots. You need JavaScript enabled to view it. if you would like to talk to him about building your .338 Lapua Ackley Improved.

The brass pictured below was fireformed by Chris with GWT .338 Lapua brass. GWT offers a very high quality and more affordable option for reloading the .338 Lapua or for forming your brass into any of the Improved cartridges.

Long Range Customs .338 Lapua AI rifle with carbon barrel.