I keep my Mossberg 500 loaded all the time (home defense, etc.)

What's the lifetime of a magazine spring??  

I've never had an issue with the pump and load, but don't want the first to be in a defensive situation...

FWIW...



I have a 1924 Remington Model 10 that my grandpa gave me. He kept it loaded all the time as do I - the spring is still strong and the gun functions flawlessly.

So you're saying about 100years?!?!  

Springs don't wear out under constant pressure, they wear out with repetitive use. You can load you tube for 10 years and the olny damage you will notice is with the shells.

They will last forever. If they don't spit out the shells while loading, then it is time to replace the spring.

I received a 1909 Remington Autoloading Shotgun(aka Browning A5 made on license by Remington). It still shoots just fine these days. Like one of the previous posters said, it is reps not compression that kills springs.

Different springs last differently. Stock Benelli mag springs are crap and take a set FAST, while other springs from other makers tend to do better. All depends.

Where do you get this info on Benelli springs? Have you seen departments have this issue? The reason I ask is that I keep my M1S90 tube fully loaded, with one on the lifter.

I have owned 2 Benelli's.  On my last one got the FL tube and installed an M1S90 spring in it to make it reliable. That spring started life at about 37" and the other one at 40" (I always buy spares). By the end of the first range trip, with each spring (I swapped them out after the first trip, curious of the other would set this bad) they were both around 34" in length. After another couple of trips, 32" in length. Another trip and it was down to about 30-31".

Also, just compress one. It doesn't feel good in the hand. It is stiff to compress, sure, but it has a lot less springyness to it than my custom spec spring from Wolf that I now use, even though they both seem to have the same amount of "force" per distance compressed. (It is spec'ed to the proper wire diameter as Wolf's standard wire for this application is thinner than it should be).

I just find that the Benelli mag-tube spring takes a massive set, this has prejudiced me against it. I have heard complaints from other individuals as well about this. It never caused any issues with feeding, but I only put 500 rounds through the weapon.

My old LE agency had a bunch of 590 shotguns.  They sold them off for new 870s due to weak mag springs causing malfunctions.    Ya I know it would have been cheaper to replace the springs but the sheriff wanted the new Remingtons.  Weak springs can happen.  If you ever buy a new mag spring I recomend Wolff springs.

True dat.  I replaced the spring in my 590 for being too weak.  Honestly I think it was cut too short to begin with.  The Wolff spring was nice and long so I cut it down to accept 2 3/4 shells.

12 Gauge,
I haven't had any problems with my Benellli, but like you, the mag spring doesn't give me any warm and fuzzy feeling about it's strength.  Just for CYA, I am going to order some Wolff Springs. I have used Wolff in my 870, Sigs and mag springs, and they do seem heavy duty.

What Benelli do you own? My springs are custom designed for a 7-shot M4 application. I would suggest you follow my lead if you have an M4.

I have the Benelili M1S90, and use both the 5+1 tube, and sometimes will use the 7+1 tube. Does Wolff make springs specifically for a 5 shot and 7 shot tube?

No, they just make generic stuff based on length of the spring you want. Mine was part of a custom order by the guy who machines the parts I run on my M4.

I went to the Wolff website, and they list mag springs for 5 shot and 7 shot tubes, but for the Remington 870.  Since the inside of shotgun tubes are all the same, I would certainly assume these would work for my Benelli.  When I want to make my M1S90 hunting legal, I remove the extension tubes, and use my Wolff springs that I have for my 870 with 4 shot tube.

Yeah, I ran a Wolf spring for a 7-shot.

Fail. It has less pressure on the last round in the mag than a stock M1S90 spring.

Now I run custom stuff only.