point of aim-point of impact problem

[MAGGUNS]

I recently traded for an 870 12 gauge with a  23" barrrel with the fiber optic rifle sights. The gun is shooting center of pattern about a foot off of center at 30 yards and I have used all the adjustment in the sights. I want to keep open sights, Is my only option to send the barrel to a smith and have the point of impact adjusted? Any recomendations on a good shotgun smith would greatly be appreciated. Thanks

[WiLL B]

Sometimes it's the choke tube. Try a different choke first.

[MAGGUNS]

Three different chokes and six different loads and all bassically the same results. 

[MAGGUNS]

Have you moved the front blade part of the sites yet? It should be in a dove tail setting and you can drive it to the left or right as needed.

John

Yes, tried that also.  I have tried everything I can think of.