On a whim, I put a bid in on GB for a Mossberg 500 Bullpup, the official gun of 80's bad guys, and for good or bad, won it.

Should be here in a week.

Who else owns one?  What's to know and learn about it?

I'd watched a video about it some years ago - my remembrance was that you could take the barrel off to clean it, and that's about it.  The Mossberg 500 receiver and trigger group were secured in the plastic bullpup housing to the point that while technical possible to get those out, it was far more of a hassle that you ever should.  So I suppose to you clean it via GunScrubber and other spray and drain solvents.

Should be a fun gun for blasting at the range, and taking me back to my days of 80's youth.

I had a friend who owned one in the late 80s.  I shot it quite a bit.  It handles kind of clumsy, and definitely kicks.  It was a good idea poorly executed.  Nowadays, it would have a light,  laser and a red dot sight, I kind of liked the simplicity of the design without that.

Should be fun w/ mini-shells and an elevator mod.

The Mossberg 500 Bullpup has a particular "quirk" in that once you fire them, they tend to relock shut rather than allow you to pump the action rearward to eject the spent shell & load the next one.

Several examples I & others owned experienced the same thing so not just "one operator error" had that same "quirk" !

Hope You Enjoy It!  

State of the 80's, but should include a MP3 player with this always on...



Bigger_Hammer

Yeah, my fear without having worked on it yet is that if a shell gets stuck, could I ever get it out?  I'll see what kind of worst case scenario I'd be looking at if a mini doesn't feed correctly.

Should be a hoot to shoot.  Gonna get my square tie and Member's Only windbreaker on while firing it.

Hmm, if you "pre-load" the action by pulling back on the slide before firing it, would it still do this I wonder?  That's my usual method for pumps anyway - put some compression onto the action then let the recoil assist the cycling.

I had one in 1988 that would slam fire but not all the time. I got rid of it and never looked back.

I had one for a few years in the early/mid 90's. As far as malfunction clearing, it's about the same as a standard M500...the stock is just a plastic shell and the loading and ejection ports are just about as accessible as a standard 500. It's not nearly as hard to access the chamber as on a bullpup rifle that has a small ejection port and deep magazine well restricting access to the chamber area.

Mossberg may still have manuals and could send you one.
Also, there may be videos on Youtube on disassembly.

I don't recall ever hearing that the bullpup 500 couldn't be field stripped.

As is not at all uncommon with standard shotguns redesigned as bullpups, the 500 had problems of various sorts.
The bullpup shotgun didn't come into it's own until companies like Kel-Tec did dedicated bullpup designs that were not modified standard guns.

I took one apart and cleaned it for a customer years ago. I couldn't find any tech info at the time, but it was pretty straightforward.

The way the carry handle is attached, it can get damaged if you stress it sideways too much, but it handles vertical stresses just fine.
Per the manual, there's one single bolt through the rear of the plastic handle, through the heat shield, and into a threaded insert in what would otherwise be the rear sight dovetail. The front of the handle is just riveted to the heat shield (and of course the very front of the heatshield is clamped around the barrel as usual).

The forend assembly can get loose just like any other pump forend, so be sure its retaining ring is tight when you reinstall it. (Just a touch of blue LocTite doesn't hurt either.)
I didn't have any issues with it unlocking like it should after firing (possibly because I did the above, but that's something I always check on pump guns).

It is an awkward and heavy gun that doesn't point naturally at all (unlike a Steyr AUG, for example).
Looked pretty badass in the original Stargate (1994) film, which is the first place I ever saw one.

Mossberg made them from both the 590 and 500, but I think the 500 version was more common.
Anyway, cool toy! Congrats.

Factory manual: https://www.mossbergcollectors.org/bullpup.pdf

Huh - a crossbolt safety.  Wonder if that's where they got the idea for the Maverick 88.  And RETAINS the receiver safety, which I presume is inaccessible under the shroud.

OP, you should get a polished wood pump grip for it, looks like it would drop right in.

Is that stock body plastic? I'd stay away from solvents like gun scrubber. I've personally done more harm than good with that stuff. Now I just run my guns wet with something like CLP. Something that doesn't hurt plastic.

There's a claimed plastic safe GunScubber that I've used for many years, that has yet to harm any of the plastic items it's been in contact with.

That said, good advice to be on my guard about it, and try a test area first.

The original sliding safety is inaccessible under the shroud.

IIRC part of the wall prevents it from being assembled unless it's in the forward/off position.

Yes it's plastic. Idk if it's Nylon 66 or something more basic.

The one I handled showed no signs of polymer degradation.

3-D print replacement shells for the win?

O.P. will have to keep us up to speed on his Adventures in "Retro Pump Guns of the 80's"

Bigger_Hammer

Got it in yesterday, and it's so cool!  I feel like the guy from the end of Predator 2, who was sporting it around saying "We were so close!"

Pics later this week, not that it's anything you all haven't seen.

It has this goofy grip safety that now off safety all the time, via two rounds of electrical tape.  Does wonders for it, as you don't have to have a super firm and straight on grip on it to be able to get it to fire  it.  Don't see the point of it anyway - maybe it was cuz the shotgun is so short that an AD hits you and not something downrange.

Sights are like a super sized snubbie - front post and a channel.   I'll paint the front post red and at least it'll have some contrast.

Lockup is tight, it handles pretty well.  You can't do much cleaning on it save for taking the barrel off.  The 500-590 series is a pain to re-assemble even on a normal configuration, so it'll be a spray and toothbrush scrub for the internals.

The trigger is part horrible part OK.  There's a lot of take-up from moving into place a 6 inch section to get to the real trigger under the receiver, but once you're connected and have pressure on it, it's fine for a shotgun.

Should be a hoot at the range.

Looking forward to two-tone pics!  

We are looking forward to the live fire and a.a. range report - 80's style!



Get Sum!

I whiled away the afternoon cleaning the M 500 BP as best I could - all I dared to do was to take the barrel off.  I vaguely remember watching a video where some brave soul had taken it out of the chassis, and it didn't look simple to put back.  Interestingly, along the section that covers up the mag tube and action bars, there's a printed and glued to the side parts list and what looks like instructions - maybe that's either for the assembly people in the factory, or the (foolish) owner who takes it apart.

Anyway, half a can of Gun Scrubber and a tooth brush got it as clean as it's going to get.  There was a bit of surface rust on the barrel that I steel wooled and the cold blued.  Also painted the front sight to red color, to get some contrast from the rest of the black plastic sight channel.

I put some rounds in the mag tube and cycled it manually - no issues but you have to cycle the slide like it owes you money - otherwise the rounds just drop onto the lifter.  Probably wouldn't happen with a fired shell that's 25% or less of the weight of an unfired one.

The 500 BP didn't have a full length mag tube, so it's only 5 in the tube and one in the chamber.  Mossberg also made a version of this from the 590, which I believe has a 20 inch barrel, so it's a 9 shot.

It feels and handles far better than it looks.  Looks on the table very clunky and heavy, and while it's no lightweight, the trigger grip is about center mass, so you can one hand hold it pretty easily, which you can't with most long arms.  I also tapped the grip safety shut - it's a pain to grip it exactly right to overcome the safety, then have to deal with a long bullpup trigger too.  So taped and going to forget about the grip safety.

Should be a hoot to shoot and remember my days of youth, watching Vice or any number of 80's action flicks.  Plus genuine Parachute Pants with zipable legs, thanks to Backbencher!

Since this is just a fun shotgun, I might look into using mini shells, which I've not fooled with before.  I believe they work best with some sort of adaptor - does it clip into the lifter to "make up" for the short shell?  You don't have much room to work with on the Bullpup, so I'd want something that is easy on/off.


Attached File

That's awesome. I think I have a mini shell adapter I'm not using if you want

Looking forward to the action shots - bonus points for dangling pasties.  

The difference between the 88/500 & the 590 series are the barrels and magazine tubes - which unscrew from the receiver.  So if you want a larger mag capacity, you can unscrew your short tube and screw in a 590 type.  You might have to alter the forward part of the bullpup shell to fit.

There are 3 ways to feed mini-shells in the 88/500/590:

1) Factory S elevator, which so far Mossberg only installs on the 590S guns, but should be a pretty much drop in fit in the rest of the series;
2) A replacement elevator which claims to run both normal & shorty shells, made just north of D/FW in Texas, not expensive, but has mixed reviews;
3) A rubber tip that slides onto the existing elevator, & restricts use to mini-shells only until it is removed.

That would be great.  I'll message you with my address and send you a check for the postage.  Thanks.

I'll try to get it in the mail tomorrow

Thanks.