I plan on taking a 10 x 19 inch sleeping...
I plan on taking a 10 x 19 inch sleeping bag with me. How do you think this will fare being inside this pack?
Kelty lists the dimensions of the pack: 34"x16"x16.5". You'll have to carry the sleeping bag vertically or use a compression sack to cut 3" off the length.
You can't see it, but this pack does have the ability to use webbing or cord to secure something (probably a tent or sleeping bag) to either the top or bottom. I'd recommend doing that over having it inside the pack. Most Backpack covers are built to accommodate doing this if you are worried about rain.