Mossberg 500 SBS conversion

[NPaz]

Hello everyone,
On an impulse I bought a beat-to-hell demilled Mossberg 500A parts kit and a brand new stripped receiver with the intention of building a form 1 SBS. I’m wanting something like the old compact cruiser with the folding vertical grip. I have access to a mill and lathe, so that part won’t be too much of a hassle. The part that I am curious about is the magazine tube. How should I go about shortening it? If I’m being honest, I’m not very good at threading on the lathe. Has anyone removed the threaded boss that the takedown screw threads into, chopped the magazine tube, and then rewelded/brazed it back in place?

 

[Jlwilliams]

I haven't done it but I think it looks fairly straightforward. I'd cut the tube to length, then take the stub with the threaded boss and grind/ file away the remaining tube from it.

I would think either silver solder or a couple of small plug spot welds would be the way to put it into the shortened tube.

 

[GymB]

Maybe I’m missing something important, but is a 5 shot tube about the right length? Check ebay, $30.

 

[Average Joe]

Maybe I’m missing something important, but is a 5 shot tube about the right length? Check ebay, $30.

I believe you are correct. Unless he has one of those 7 or 8 round models. Not even sure if they still make those in the 500 series. The ones that I have seen recently that hold more than 5 rounds are usually 590s.

 

[Dale Gribble]

Hello everyone,
On an impulse I bought a beat-to-hell demilled Mossberg 500A parts kit and a brand new stripped receiver with the intention of building a form 1 SBS. I’m wanting something like the old compact cruiser with the folding vertical grip. I have access to a mill and lathe, so that part won’t be too much of a hassle.

You looking to build a SBS or AOW?

 

[Button Pusher]

Have you seen the VRF14 semi auto firearm?

VRF14

The VRF14 is the first semi-automatic short barrel firearm of its kind. It boasts a familiar pistol-style grip so you can shoot 12GA shells from the hip.

www.armscor.com

 

[NPaz]

You looking to build a SBS or AOW?

SBS, the receiver I picked up is a new take-off but I’m fairly certain it’s not a virgin receiver.

 

[Jlwilliams]

How short are you going?

 

[NPaz]

Maybe I’m missing something important, but is a 5 shot tube about the right length? Check ebay, $30.

I’m wanting to got for 3+1. If you look at the M590 compact cruiser they used to make, that’s what I’m seeking to emulate (using a 500)

How short are you going?

10.25”. It’ll give me the 3+1 capacity I want, and keep my hand a few more inches away from the muzzle than a 7.5” would 😂

 

[NPaz]

Have you seen the VRF14 semi auto firearm?

VRF14

The VRF14 is the first semi-automatic short barrel firearm of its kind. It boasts a familiar pistol-style grip so you can shoot 12GA shells from the hip.

www.armscor.com

i just looked it up and while it’s neat, I’m a sucker for the classics.

 

[NPaz]

I haven't done it but I think it looks fairly straightforward. I'd cut the tube to length, then take the stub with the threaded boss and grind/ file away the remaining tube from it.

I would think either silver solder or a couple of small plug spot welds would be the way to put it into the shortened tube.

I’m thinking the same thing, but since I don’t have the kit on hand yet, I wanted to make sure there weren’t any idiosyncrasies I wasn’t taking into account.

 

[Average Joe]

I’m thinking the same thing, but since I don’t have the kit on hand yet, I wanted to make sure there weren’t any idiosyncrasies I wasn’t taking into account.

Since you are going that short. Following @Jlwilliams advice is the way to go.