I have significantly more time on 870s than any other shotgun.  I have been considering a Mossbeg 590A1 as my primary shotgun to replace my 870.  I like several aspects over the 870, however I have noticed in the 8 different 590 and 500s that I have had the opportunity to shoot the mag springs are noticeably weaker that the 870s that I have used.  Is this common?

Yes, their mag springs suck and I highly recommend you replace them with Wolff XP springs.

Yep, especially if you ever get an auto.

A 3 pack is like $15 shipped.

+1

What he said...

Sounds good thanks.

metal follower too

a good pump used to be standard in my day. sadly so much junk nowadays I'm 57 now...........so much for fancy CNC shit QC?

Go to a show and buy some old shit

I replaced my mossberg spring with a replacement from scattergun technologies. Much more positive feeding now.

I have access to around 30 870 police magnums and 4 590s that I use for shotgun training.  The 870s seem to break a fair amount of ejectors, shell stops that come unstaked frequently, and trigger groups/shell lifters that shit the bed.  Not to mention the horrible rifle sights that were chosen over the bead at a time prior to ghost rings.  

From my observations on a significantly smaller scale vs the 870 I have found the 590 to be a rather crude design with many parts easily replaced without a certified gunsmith.  Better ergonomics, dual extractors, seemingly less complicated trigger mechanism, and the ability to get a sub $500 police duty rated gun with a drilled and tapped receiver and very rugged ghost ring sights is very appealing. The magazine springs being weak in every 590 that I handle does cause concern, but that is easily remedied.  I did watch some interesting malfunctions on the 590s this week while teaching a shotgun school.  It appears the weak springs cause the shells to sluggishly eject from the mag tube which cause some issues.

I did this with my Mossberg.  It wasn't that old, probably made when I was a teenager, (it does have a serial number).

I am a firm believer in changing springs if they weaken over the years, and many times they do.

Brand doesn't matter much when it comes to springs.  Springs are a consumable commodity, they will some times need replacement.

Not always though.  I have never felt the need to replace the mainspring in a 1911, for example.  Of course, they are overly strong to begin with.

Most tube fed shotguns with some years and some use on them will probably benefit from new mag springs.