Ruger .44
Oh yeah, they sure will kill deer!!!!! I've got two of those little gems, one scoped, the other wears an XS peep set. I hunt the scoped rifle every year, this year it killed a 5pt at about 75 ds. A 200 gr HP tight behind the shoulder, yielded a pass through, and a short death sprint, much like other deer shot with other "real" deer calibers and hit similarly, This most recent .44 buck was just as dead as if I'd shot him with something "big".
Big typically means heavy too, and often long. I doubt my scoped .44 weighs much over 6 pounds, and the peep rifle likely 6 or less. Length is one inch over 3 feet.....37"!!! Toting a climbing stand, on grades, with no trail, much any distance, the tidy light rifle is much appreciated these days. My Dad's rifles all seemed to get shorter and lighter when I was a kid, now I realize why!!!!! Too, no need to go big if you don't have to, all my .44 kills, in fact most of my rifle kills period, have been well under 100 yds, many half that, and some half again, or less.
My only criticisms of the old Ruger .44 carbines was the slow twist rate (1-38") yielding sketchy accuracy in both my rifles, and the miserable trigger. Aside from that, both have been brick like reliable, using a variety of ammo and bullet weights.