This is a copy of my response to your other post on the same subject.
Kirby does not currently have a web site bit he mentioned recently that he is working on one. This is a VERY BUSY time for him so he may not get on here as often as he'd like so I'll give you a little bit of info to tide you over.
The best way to contact Kirby is by email and he checks it daily and will answer as quickly as he can. email@example.com
Use the search feature and you'll get a ton of reading on the 338 Allen Mag.
338 Allen Magnum
408 Chey Tac - parent case
Ballistics: 300 gr. SMK or ULD RBBT @ 3350 fps in 32" barrel, @ 3450 fps in 36-38" barrel; 350 gr. ULD RBBT @ 3150 fps in 32" barrel, @ 3250 fps in 36-38" barrel. This is a true power house and the current largest version of a 338 cal. wildcat on the 408 CT case as far as case volume is concerned. Ballistic performance is simply unmatched by anything out there in a conventional shoulder fired rifle. Even the 50 BMG pails in comparison in every ballistic category, except kinetic energy. This performance comes at a price as far as loading dies are concerned, but it is a one-time expense for the ultimate in ballistic performance - a pretty small price to pay. This chambering, along with the 300 AM and other cartridges after this, will require larger custom receivers because of the size of the case used with this round.