Technically - How to make a SBS?

[Lightsped]

I currently own NFA items so the whole NFA process is completely clear to me. No need to clarify that.

My question is, if I want to make a 14" barreled version of my 590A1 what all parts will I need to buy?

Or would it be cheaper/easier to just buy a factory made 14" barreled 590A1?

 

[glocknurse]

You could just cut the barrel down to 14". You're only limited by the length that the forend sticks out.Then you would have to redrill for a bead.

 

[chas08]

I'm not familiar with the 590 A1, but if it is a gas operated semi- auto, you may need more than 14 inches of barrel for it to function properly.

 

[Sam1911]

Do you have the 6-round or 9-round 590A1? Did it come with an 18.5" or 20" barrel?

You're practically limited to the length of the magazine tube attachment point. To go that short you'll need to get a new shorter (5-round) tube and barrel with the attaching ring in the right spot for it.

Probably makes more sense to buy that ready-made. See Mossberg's LE catalogue for some pics which should explain it: http://catalogs.mossberg.com/2014_Law_Enforcement/ (Check page 4.)

 

[Nickel Plated]

If you have the 5+1 590A1. You can just cut the barrel down flush with the magazine lug. But that's not really loosing a whole lot of length. Hardly worth the $200 stamp.

Mossberg does offer them as 14" 4+1 AOWs. Or they offer a kit that you can use to convert your own. Includes the 4shot mag tube, 14" barrel, new foreend assembly(a bit shorter than the standard forend) and magazine spring.

I'd say you might as well convert yours. The only tough part is removing the original mag tube. It's screwed into the receiver pretty tight. And with some thread lock too. So a heat gun, vice and channel locks will be needed.

Mossberg doesn't show the parts in their catalog, so you'd have to call them and order. or scour the usual places like Brownell's and Midway.

 

[rcmodel]

A good strap wrench might be a better idea then channel-lock pliers, or a pipe-wrench!

That is, if you intend to preserve the original mag tube for re-use, or sale.

rc

 

[ApacheCoTodd]

I have a sense that 14 inches is going to require relocating the magazine tube hanger lug.
If so, are you prepared to do this?

 

[USAF_Vet]

I've seen pictures of it done right (new Mossberg parts) and I've seen firsthand done wrong. Well, correctly, but poor execution. Seen a Mossberg 500 where the mag tube was cut down, barrel lug cut off and barrel chopped, and everything welded (poorly) back together. You could see the stress fractures and subsequent welds. Made me wonder if the thing was legal. Probably not, since I don't think short barrel rifles and shotguns were allowed in Michigan at the time.

 

[Lightsped]

Thanks for the replies. My 590A1 is the 20 inch barrel with 9 shot mag tube. I have no problem ordering a shorter barrel, but my confusion was how to alter or where to buy parts for the shorter mag tube requirement.

At this moment I am leaning towards getting a factory made 590A1 SBS with bead sight. Looks like they can be found new for $500+$200 ATF stamp.

 

[rcmodel]

The only question you have to seriously ask yourself?

Is why?

What exactly will a 14" 590 do that an 18" 590 will not do?

Except cost you several hundred in parts & stamp, and get you on the ATF radar screen as a minor blip to watch for a while?

rc

 

[Lightsped]

I have bought many many guns for the simple reason of wanting to own them. Some don't make tactical sense, but its a hobby I have none the less. I would like to add a 14" SBS to the collection.

 

[HoosierQ]

I'd like to know how to get a good set of sights on mine...at the length it is. The bead is not for me. Can't find a smith. Might just sell and/or trade at a loss. I'd take a plain Jane 500 over the 590 if it had ghost right / fiber optic sights.

 

[Nickel Plated]

Seen a Mossberg 500 where the mag tube was cut down, barrel lug cut off and barrel chopped, and everything welded (poorly) back together.

Yeah...welding stuff on a gun barrel. Bad idea. Although I guess if it's right at the muzzle it's no major issue. but the Mossberg barrels aren't welded. Even at the factory. The barrel lug is silver soldered on. Which actually makes it much easier to remove and install. Atleast no fancy welding equipment required.
Here's a good vid that shows how to remove and reattach the lug:
https://www.youtube.com/watch?v=xKqoOnvpkUQ

Is why?

What exactly will a 14" 590 do that an 18" 590 will not do?

It'll make a bigger fireball and make everyone at the range go "oooohhh"

Why else would you own a gun?

 

[Lightsped]

Fireball??? You should see my Super Shorty 870! It is a 2+1 capacity 6.5" barrel.

Yeah some of my stuff is just for fun. I already have the required 18" and 20" inch shotguns.

 

[dogtown tom]

rcmodel ....What exactly will a 14" 590 do that an 18" 590 will not do?

Same answers as you could give for any gun, otherwise we would all be carrying 83/8" revolvers, 28" shotguns and the military would never have adopted the M4 carbine.

1. Easier to conceal, whether in a car, backpack, or under a coat.
2. Easier to enter/exit a vehicle.
3. Store in a safe, gun bag, scabbard that an 18" would not fit.
4. Lighter
5. Easier maneuverability in tight spaces such as a house.

That said If I could have only one shotgun it would be my 20" Rem 870 Wingmaster with standard mag tube.

 

[Arizona_Mike]

Except cost you several hundred in parts & stamp, and get you on the ATF radar screen as a minor blip to watch for a while?

Do my 12 NFA weapons make me a "major blip"?

Shockwave Technologies has published a parts list for making a 14" Mosberg 500: http://shockwavetechnologies.com/site/?page_id=438

Finding a 14″ Mossberg 500 Front End

If you want to convert your Mossberg 500A (12 gauge) to a 14” barrel—legally, of course—you will need to order a total of eight front-end parts from Mossberg. Give them a call at 1-800-363-3555 and order one each of the following:

13488 Tube Nut 500A/835 $8.53
11239P M590/835 Mag Cap Parkerized $14.00
12410P Magtube M514 Parkerized $38.00
12392P Magazine Spring Retainer 590/835 Parkerized $3.50
12194 Spring, Magazine 835 $3.50
12359 Forearm, M514 $20.00
16033P Bbl Asm 514Bead Hvy/w Parkerized $100.00
12362P Action Slide Asm 500/514 Parkerized $22.00

Prices listed above were current on December 7, 2010. Shipping ran me $14.95. So my total was $224.48 shipped.

A lot of people are using a long grip to make non-NFA PGO 14" Mossbergs. I've read several accounts on line that Mosberg will sell you the barrel if you know what to asked for.

Mike

 

[HRnightmare]

and get you on the ATF radar screen as a minor blip to watch for a while?

Good chance most of us in the NFA thread of THR already have a "blip on that radar". I know I have 7 and am probably way behind some of the other members.

Not sure what the point of criticiszing his "need" for this particular size he is asking about or making the tin hat comments provides any value to the forum, at least not this particular thread.

ANYWAY - I know it has been said but I have seen a few done afterwards with specific SBS or AOW kits.

I was interested in doing one with the rounded off grip, maybe a double barrel rather than a pump. Seems it would be awkward to cycle a gun that short, but that is pure speculation.

 

[Lightsped]

Thanks for the link from shockwavetechnologies. I currently own a 590A1 which is a heavy wall 20" barrel 9 shot mag tube. I am sure this will differ from the Mossberg 500. How will this difference change the parts list?
Thanks