I remember reading on one of the brewing forums your FG should be approximately 30% of your OG.
Caribou Slobber OG 1.052. Take .052 x .30 = .0156. Your FG should be about 1.015. If you take your OG minus your FG and multiply by 131.25 you should get your ABV.
1.052-1.0156=.0364 x 131.25=4.7775. Approx. 4.8 ABV.
Someone please correct me if I am giving out the wrong information.
Happy brewing, Joe