I've been having some problems with my new 870 Police. It usually holds the normal 6 in the magazine, however once in awhile I'll only be able to fit 5. The follower seems to be getting stuck. If I give the extension coupler a few whacks it usually fixes the issue. If not, I have to take the magazine apart and reassemble. I purchased a Vang Comp follower thinking it would fix the problem. It seems to have made the problem worse! Any idea what's going on?

Mine started doing that ever since I installed a GG&G follower.

That's the second aftermarket follower I've installed that has done more harm than good.

A friend of mine had a similar issue with his new 870P. He replaced the magazine spring with one from Wilson Combat and that actually took care of it.

Barrel clamp cranked down too tight?

I have seen this problem before.  It is the follower catching between the extension and magazine tube.  It seems to occur when loading shells of the same exact length that just happen to catch the sweet spot.  I solved this by beveling the edges on the back of the follower and the inside of the tube extension.  

Check your shell latches to make sure they are even and staked properly, make sure your follower isn't backwards, make sure the coupler is tight, look inside the mag tube for any dents/bulges. Call Remington up if you can't figure it out.

+1 on the problem being at the extension. If it's ever been tightened too much into the coupler/cap, then it has deformed at the edge and created a burr. It also may not be completely round, or the cross-screw that secures the clamp may not be properly located in the groove it's supposed to rest in. Check all that, and if you don't have a smooth transition where the extension starts, run a round medium polishing stone over the edge a few times until it feels smooth, then be sure you only re-tighten the extension itself to where it just touches. The coupler/cap is the part you want tight. The clamp screw should be really tight also, once you know it's centered in the slot.



 

The extension does not need to be tightened as much as people think.  If you have the factory one, some don't know it's actually two pieces also.  The factory correct way to reassemble it is to spin the base (the knurled ring) onto the magazine tube first, but only finger tight, no tools.  Then install your follower the correct way (this can catch shells too) and the spring.  Then put the extension itself on, but that one only gets barely tight.

Also if it is really new, call Remington.  If your mag tube is cinched down too tight already it may be beyond your ability to fix.

Here is the best fix dude, take out any aftermarket parts you have, call Rem and tell them what length extension you have and then you can order the correct length spring and follower from them. Solved. Rem followers are the best options in 870's because aftermarket ones do cause more harm than benefit.