Custom Rifle Build: The .450 Ackley

I consider myself a “rifleman”. I truly enjoy hunting with a fine rifle as much as the next connoisseur, maybe a wee bit more. That being said I feel that most of the factory rifles made today are lacking in some features that I look for.


I want to do another hunt overseas for dangerous game knowing full well that this may be the last of these hunts for me. I am not sure at what point I made the decision to start planning this hunt or to build a rifle especially for it (as well as for the occasional grizzly hunt up in the Skeena region). I decided to do this project myself with assistance from a machinist friend of mine to guide me through the machining process.

I wanted a “stopping rifle” and settled on an action. Actually I bought a new CZ 550 to cannibalize for parts. The big “Mauser” action has several features that will make the rifle a tried and true instant classic.


A new barrel was ordered, in the same caliber/diameter but with a 40% faster twist (1-10”) rate and a slightly heavier contour. The faster twist rate will ensure bullet stability and straight line penetration through the thickest brush, hide and bone. That is essential in hunting large game in heavy cover, the bullet needs to get to the vitals from any angle if necessary. The faster rate will also allow me to shoot long for caliber bullets (such as solid copper) if desired. The original factory barrel will be destined to the top shelf of my safe as future “trade fodder”.

The factory stock will stay temporarily, as I work up loads and test the rifle, but an English walnut stock blank that will grace the rifle upon completion was actually purchased prior to the rifle/action itself.


The caliber I chose to build is on the large side for here in BC, but not over gunned for across the pond where game can fight back as the norm not the exception. I chose to build a .450 Ackley which is based on the full length .375 H&H, not shortened as some of the other variants are. The Ackley version also allows the shooter/hunter to shoot the .458 Win, .458 Lott and the .450 Watts through it if required. With the caliber and basics chosen now the work begins, I’ll let you know how it goes.