Welcome to the forum, FrozenShorts

The smarter guys will be along in a bit.  First, The odds of having a RR carbine is very small.  I looked in Frank Mallory's book The Krag Rifle Story and there are only two 35K carbines listed.

I can not tell too much from the tiny picture.  You could have a bubba'd carbine stock or you could have a bubba'd rifle stock,

Could you provide a few larger photos of the left side full length, right side full length and a close up of the left side of the receiver only?

While you are at it close the bolt and run a cleaning rod down the barrel to measure the length from the bolt face to the muzzle.  Twenty-two inches is a carbine barrel.  Twenty-three is not.

Best regards