shooting it a lot is still probaly the best way, there are other ways like valve grinding compound, but if you go that route you may get it too loose,best solution is just to sit and keep opening and closing it a few hundered ( ??? ) times, that way you will be keeping the hammers cocked and wont have the extra stress of the cocking hammers. Or you can loan it to my Son, who dropped his new pump gun in the sand on his first day out, that will also loosen a gun up,,, Just joking dont try this at home unless you are a pro. LOL
Check to see if the gun is starting to gauld at the intersection of the forearm and the receiver. This was a condition of one gun I owned at one time. The gun was almost hard to open and didn't loosen up . Then I noticed the metal rubbing and removed the gauld with a dremel tool.
I took the gun back to gun shop,and dealer told me it's common in low end shotguns.He said to try graphite,and work the gun as drhuner said.I will check to see if any gaulding is present.Thanks guys.Houston6,I paid $495 for the gun.
We had a guy at the range last week with a Daly. His was really tight. When we had him break it down, it was totally dry. Make sure you use a good quality grease like STOS on all surfaces that move or rub against one another.