I have shot slugs out of cyl, improved, modified, full, and x-full with no problems at all. I was pushing the limit with x-full just to see if it can be done. I shot 10 rounds out of each choke size. Other then the x-full choke being very hard to remove after, there was no problems. Accuracy did however suffer as chokes got tighter for some reason. Improved shoots best for me.