Yep, I keep my beloved 870 loaded in such a way that the first two coming out are 2 3/4 shells loaded with #8 shot. The next four are 3" mags loaded with 00 Buck.
The birdshot is pure poison on the rattlesnakes that infest this part of the state. As for the buckshot, well, if a guy can't put it down with four 3" shells loaded with #00 buck, then GOD doesn't want it put down....