Have you shot your yet? I put about 60 rounds though mine today. 50 rounds of bird shot, and 10 rifled slugs. I had some issues with mine when it came to racking the slide. you have to rack it with some authority, or the gun wouldn't cycle.
I did a comparison with my other 870 field model, and that one the action was smooth as silk. But that gun also has a lot more rounds though it. I bought that one used, and since I've owned it have put about 200 rounds though it.
I just cleaned my tactical model, oiled everything up, and racked the slide about 100 times. Seems to be a little smoother now.