My very first deer rifle was a Ruger .44 carbine - many, many years ago. Seems to me the barrel was about 18" and the MV was about 1750 with 240 gr. loads. I don't know what you are comparing the carbine to, but I would agree with old06 - I don't think there would be much velocity difference with a different action and a slightly different barrel length, nothing significant anyway. JMO and old memory............. Good luck with your hunting tomorrow.