View Full Version : Mag Ext. for Mossberg?

August 27, 2002, 09:46 PM
Well, I've looked in a few of the more obvious places, (Mossberg, Tacstar, Natchez etc) but can't find a magazine extension tube for my 500. Does anyone know of any sources? Mine is the 500 18.5"bbl with 5 shell capacity (w/plug removed). I'd like to add 2 more rounds if possible.

Andrew Wyatt
August 28, 2002, 12:13 AM
the only way to increase the magazine capacity of your mossberg is to buy a 20 inch 7 round barrel and magazine tube/spring/follower. the barrel attachment system precludes the use of extention tubes.

basically, no one makes them because there's no way to extend the magazine capacity without getting a new barrel.

August 28, 2002, 07:54 AM
Oh! Drat, should have checked before buying that model, but I'll probably struggle along ok with 6 shells.;)

August 28, 2002, 11:17 AM
If you don't already have one, a receiver mounted Sidesaddle shell holder will put more 6 more shells within easy reach for combat reloads and you can practice using shoot-two, load-two, shoot-two drills.

Some TFL'ers recommend against putting the Sidesaddle on the aluminum receiver on the M500 because the pin/screw might enlarge the holes. I've settled on a compromise of only shooting a few "realistic practice" shots with shells in the Sidesaddle and then shoot the other 200 shots with the Sidesaddle empty, on the theory the the empty Sidesaddle has very little mass and inertia and thus won't screw up the receiver.



Andrew Wyatt
August 28, 2002, 05:42 PM
I've a but cuff on my 500 and it seems to work just fine in the ammunition carrying department. I don't like sidesaddles because they make the reciever wider and make the balance funny, whereas the butcuff makes the gun wider in an area where it really doesn't matter.

I did some research and bought the 20 inch barrelled 7 round model instead.(it's got mossberg factory GR sighs on it and one of them fancy dancy do all slings, as well as a cheekpiece (which incidentally is held on by the buttcuff)

August 28, 2002, 07:34 PM
Well, the reason I bought the model I did was that it came with two barrels, one the 18.5" security version, the other the 28" vent rib hunting barrel. So, it's a trade off, only paid $219, so I really can't complain. I could have gotten the 590, but then I'd have had to buy the vent rib extra. Just didn't think about extra mag capacity till I was reading about someone else's add-ons!
Of course, now I have a (sort of) reason to buy another shotgun, one that'll take all the bells and whistles;)
Of course, explaining that logic to my wife is another thing!
"Oh, wait, honey, this is YOUR shotgun, I han't picked mine up yet!"
Yeah, yeah, that's the ticket...

Andrew Wyatt
August 28, 2002, 10:46 PM
my parents got mine at a big 5 sale, too. they paid 239, i think.

You don't need extra capacity on your shotgun. if you can't handle it with five rounds, you're probably doing something wrong.

you can get another mag tube and the 20 inch barrel, for less than the cost of a new shotgun.

August 29, 2002, 04:12 PM
If you're really looking to up the ammo capacity on your 500, check out these guys:


The sidewinder looks pretty sweet, but it is a bit pricey.

August 29, 2002, 08:40 PM

August 30, 2002, 02:36 PM
www.e-gunparts.com has the longer Mossberg mag tube and the 20" cylinder bore barrel available.

August 31, 2002, 09:08 AM
I've had a Knoxx on order since the SHOT Show. Am getting excuses instead of my order. Bummer, since I really wanted to try it out on a spare 500 I have laying around. Sounded like a good idea, a drop-in box magazine conversion. Knoxx was also prototyping an 870 conversion there, but it required some cutting on the receiver (bottom front).