I don't know why everyone is saying .44 mag is more "readily available" than .45 because for just about ANY pistol chambered in .45 Colt, you can buy a .45 ACP cylinder. Now that's what I call readily available, better for plinking, and cheaper. Plus, .45 Colt can be loaded just as hot as a .44 mag (Maybe not for every gun but should for most new pistols). I own a Ruger New Vaquero and it has held up for the past year of probably a 1000 rounds of hot .45 Colt + even more factory loads. And I have a .45 ACP cylinder that is awesome for plinking and cowboy action shooting.