Dale,
That is interesting and useful information regarding the .44 mag in carbines. And yet, the discussion here is the .357 mag in carbines. The .357 mag is capable of much better accuracy than the .44 mag, maybe because of ballistics or recoil factors.
A 3 inch MOA from a carbine in .357 mag is nothing to complain about, until you realize that other carbines in that caliber, including the Marlin 1894, get much better accuracy than that, and they aren't even bolt actions.
Hopefully, some range reports will come in on the new Ruger, showing better accuracy with factory ammo than the two inital reviews that have been published on-line.
Regards, Mannyrock