I use 12 Guage Rotweiler Breneke 2 3/4" Slugs. Works as good as any... I killed 4 Deer in 3 years with them. Missed 2 this year though. Well actually one... missed the Doe, but i could'nt see much of her Neck. Rushed my shot.
The Spike I missed with my first shot, and I connected with my second shot.