A few years back I replaced my factory 7 shot 870 magnum magazine tube with one from Wilson combat because of the claimed extra power.  

Today I was doing tactical sidesaddle reload drills when a very disturbing thing happened.  With the tube fully loaded with six shells, the gun jammed when I went to eject the 2nd shell from the tube.  The round didn't feed all the way out of the tube.  Turning the gun upside down I could hear the rounds inside the tube SLIDING back and forth as I tilted the gun!  It was as if the spring stayed compressed and wouldn't uncompress to push out the round!  A few pushes on the partially ejeced shell caused the spring to "spring" back to proper position.  However, now it is happening all the time.  This is a VERY bad and dangerous thing.  I need to trust my life to this gun, and I can see no reason why this is happening to a practically new spring?  Are the wilson springs junk, or are stiffer magazine springs less reliable than weaker ones, or?????

This has prompted me to want to purchase an 870 WOLF magazine spring for the extra power, but from what I can see here

http://www.gunsprings.com/RifleShotgun/Remington_RsNF.html

They only offer a 5 shot model!  Any help would be appreciated, I need a solution NOW!  Everyday I go without it's proper function, my life is foreit!

http://www.brownells.com/aspx/ns/store/ProductDetail.aspx?p=12523&title=MAGAZINE+SPRING+PERFORMANCE+PACKAGE

7 shot there, they claim good for 6 shot too.

After you make sure your mag tube is clean and the spring isn't catching on anything, you could also try a different follower:
http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=20384&title=SHOTGUN+FOLLOWERS

It's possible the inside of the tube and the spring are gummed up or even rusted.

You should clean and re-lube the magazine tube and spring just like you do the rest of the gun.

Second possibility, the spring may be kinked or entangled.  Sometimes if you attempt to push in one too many shells, the spring can entangle.

You're first course of action is to disassemble the magazine and see just what's in there.

Hmmm, if you check that spring is made by Wilson, the same spring I have now!!

Quoted: Hmmm, if you check that spring is made by Wilson, the same spring I have now!!

I'd be willing to bet Wilson doesnt even make their spring.

Quoted: It's possible the inside of the tube and the spring are gummed up or even rusted. You should clean and re-lube the magazine tube and spring just like you do the rest of the gun. Second possibility, the spring may be kinked or entangled.  Sometimes if you attempt to push in one too many shells, the spring can entangle. You're first course of action is to disassemble the magazine and see just what's in there.

Yep, good advice there.