That's a Daisy Model 25. Designed in about 1915 by Fred LeFevre of LeFevre shotgun fame. Daisy bought the design and made it from the 20's to recent times. Might still be made, not sure. The rifle is a take-down. Remove the big screw on the left side and it come apart in 2 pieces. It was a hard shooting gun. I have 4 of them, one from 1941 that was my uncle's. Gary