View Full Version : Mossberg 500A into 500 Tactical

July 19, 2008, 11:12 PM
I just purchased a used Mossberg 500A with a 20" ported barrel and adjustable sights.
I wanted something for home defense and my shop just happened to have this 500A for a little less than $200 so I grabbed it.

Now I want to turn it into a good tactical shotgun like the one below.


I went to cheaper than dirt and looked up some parts, but I could use some help with something. The 500A is a 6 shot and I don't know anything about choke tubes or what I need to do to turn this thing into an 8 shot.
Please explain to me how the choke tube works and what needs to be done to increase my capacity. Also give me some feedback on 6 rounds versus 8 and whether I should even bother. I plan on shooting steel with this gun down at the club as well.


July 20, 2008, 12:35 AM
To turn it into a 8 shot you will need to buy a new 8 shot bbl and mag tube. Then you will have to take the mag tube off of your shotgun and install the new one. It isn't worth the time and money. It would be better to sale the shotgun you have and buy a 7+1 500A or keep it like it is.

The more constriction tighter the pattern. It is like water coming out of a hose. the smaller the end, tighter the stream.

Cylinder - no constriction
Improved cylinder - a little constriction
Modified - a little more constriction, best all around choke tube
Improved Mod - little more
Full - a lot of constriction, used for longer distance shots and to put more pellets on target
Extra Full - the most constriction, used for longer distance shots and to put more pellets on target

Your shotgun has a cylinder choke bbl. Standard on most home defense shotguns. Some shotguns come with screw in choke tubes to change out the choke constriction. It makes the shotgun more versatile for hunting different game.


July 20, 2008, 01:42 PM
I think I am just going to stay with the 6 shot since it is for home defense and go with a shorter 18" barrel. That will probably be the most expensive part I have to get. Everything else is fairly cheap and simple to change out.

July 22, 2008, 02:22 PM
You could save yourself some money by slapping a 18-inch bbl on there and calling it a day like I did.

What I do is, I take my buckshot shells and hold them up to the picture of the black tacticool shootgun until they're absolutely foaming at the mouth, then turn off the lights and load them into my plain jane 500A. So far, they don't know the difference.:D

And, if I ever have to use it to kill some of the clay pigeon scum hanging around here, it doesn't look quite so silly when I put the 28-inch vent rib back on it.

July 22, 2008, 04:40 PM
Well I won't lie, part of the reason why I want to convert and add all this stuff is because I think it looks cool, but I also want it to be functional.

I needed a good shotgun that I could use for home defense and to shoot steel with at the range. I've always owned pistols and never had any Rifles of my own so I figured what better place to start a rifle collection than with a good shotgun.

My goal is to build my own AR15, but first I wanted to get my feet wet on a shotgun. I have LE experience with the Rem870 and M500 series so I thought that would be a good place to start.

So far the two things that look like they will cost the most is the barrel and stock if I go top of the line on both.

Dave McC
July 22, 2008, 07:00 PM
Seawolf, it's functional now. A short barreled Mossberg 500 is a great and terrific wepon right out of the box.

Go shoot your shotgun as is until you know it like your tongue knows your teeth. Shoot clays, cans, starlings and/or rats at the landfill but burn up some ammo.

When the pile of empties reaches your shins, figuratively speaking, you'll find you're holding the finest CQB weapon ever made.

Then, and only then, make any changes you want, based on experience and training, not Net myths.

Technology cannot substitute for expertise. Nothing can....

Bill DeShivs
July 22, 2008, 09:04 PM
Dave is correct!
BTW- a shotgun is not a rifle.

July 22, 2008, 09:47 PM
I think he meant "what better way to start my *long gun* collection...:rolleyes:
And I agree... I do not NEED a pistol or a rifle but gotta have a shotgun laying around... Now I have all 3... even if my pistol is only a .22 ruger MKIII bull barrel.

July 23, 2008, 02:43 AM
I did the conversion on my 500a a few months ago...EXTREMELY easy conversion. I got everything from RR Arms. IIRC, the barrel was just over $50 (mossberg 18.5"), the synthetic stocks were about the same maybe less, and the heat shield was less than $20. Arrived to me in 2 or 3 days. I kept mine a 6-shot b/c of the PITA factor of changing it and might pick up a 590 again later on to add to the collection. PM me if you need any info, etc.

Bill DeShivs
July 23, 2008, 03:01 AM
You don't have to waste money on a new barrel. You can cut the existing barrel.

July 23, 2008, 08:52 AM
I know what you mean about tricking it out to look cool. :cool: I was just trying to save you money. For my dollar, I like spending money on shooting it rather than looking at it.
But, I confess that a good portion of the enjoyment I get out of my firearms is in fiddling with them. Other people get a kick out of accessories and I think that's fine, too! People are the same way about cars.

July 23, 2008, 02:38 PM
Code3GT- PM sent, thanks

I appreciate the feedback guys.

July 25, 2008, 01:58 AM
For Code3GT or anyone else interested. Here is the Weaver 1-Piece Multi Slot Tactical Base for Mossberg 500 Matte I ordered. The cheapest i found was Midway for $6
I plan on sticking a cheap red dot sight on it.

August 10, 2008, 12:40 AM
Ok, I thought I would revisit my thread here and give an update. I've replaced the forend grip with a tactical ribbed forend and added a picatinny rail to the top of the reciever.

I originally thought what I had was a 20" barrel, but I actually have the ported 24" turkey barrel with adjustable sights.

What I want to do is switch out the long barrel for a 18.5" tactical barrel. The problem I am having is finding one in stock with the Matte finish. My shotgun right now is all matte black so it's going to look pretty stupid with a blued barrel. Where can I find a matte black 18.5" barrel for a good price?

Bill DeShivs
August 10, 2008, 01:18 AM
You should be able to get your existing barrel shortened for about $25. Why would you insist on buying a new barrel?

August 10, 2008, 01:55 AM
check out R&R Arms, that's where I got mine. I'll post a pic of my setup tomorrow after work for ya