That's a pretty broad question. It could be fouling in the barrel and a good cleaning to remove lead and copper might help. It could be that the barrel needs to be floated. Maybe it doesn't like your choice of ammo, 22s are funny that way.How can i get this model 880 22lr shoot better groups? It shoots about a 2 1/2 group at 100 yards..i have a marlin 925r that shoots a 1/2 inch group at 100 yards all day..