These parts fell out Mossberg 500!

[u/Master_Chip1545]

These parts fell out of my Mossberg 500 12gauge after installing a bolt for pistol grip that was too long… removed the trigger assembly to try and fix the issue, and these came falling out…. is my trigger group still good? Or time for a new one…. ?

[u/PM_me_ur_TT-33]

Common mistake, actually. You broke the safety.

I don't know what the small black fragment is or whether the plastic trigger housing is ok. The silver fragment is the safety block, and is replaceable. The flat metal plate part was slotted into the plastic housing, allowing the (broken) safety to hold the trigger bar downward when set to safe.

Wolverine Supplies imports Mossberg parts. Other vendors have some. If you have a mystical "reputable gunsmith" nearby they might be a good option also.

[u/Master_Chip1545 → u/PM_me_ur_TT-33]

Would the issue be solved by just buying a whole new trigger group? Or should I try and hunt the specific part that broke?

[u/PM_me_ur_TT-33 → u/Master_Chip1545]

No, at least not very well. Taking a closer look at the photos, there are two parts broken.

1. the "safety block" which is bolted to the underside of the sliding tang safety. That's the silvery fragment.
2. the trigger (bow) itself is the same part as the metal bar in the top of the trigger group, and the small black piece broke off the back end of it.

That black end piece interfaced with the hole in the middle of the Y-shaped flat plate which fell out, and the single angled-top leg of the Y hits the safety block when it's on Safe, preventing the whole thing from moving. I think the sliding plate and the plastic housing might be ok, but it's not entirely clear from the photos.

Unfortunately, perhaps being scared of their lawyers and American liability, Mossberg doesn't sell trigger and safety parts to the public. They're much harder to find as a result, which is one reason to try to find a gunsmith or inquire with the warranty/service center. Wolverine Supplies has probably heard this story before (but I don't know what the response is, well not yet).

Any other 12-gauge 500/590/88 trigger group will interchange (though there was a design change in the early '90s; those aren't a sure thing). The Maverick 88 group has its own cross-bolt safety in front of the trigger guard (often preferred when using a pistol grip), in which case you should block off the broken tang safety to avoid confusion. The 500/590 groups will additionally require the safety block replaced.

[u/Master_Chip1545 → u/PM_me_ur_TT-33]

Ahhhhhhh I see, so might be looking at having to buy a whole new reciever?

[u/PM_me_ur_TT-33 → u/Master_Chip1545]

Shouldn't have to be that drastic, though in reality that's the fastest solution, isn't it? (Quite a few Mavericks get bought each year specifically to be parted-out , or just to get the barrel, since Mossberg's parts availability is inadequate. Some of those folks are how you could get a complete trigger group.)

I should note: that trigger got a lot of force on it from the stock-bolt. I can't tell from pictures if the other parts (cross pins, sear, etc) are undamaged. Don't be surprised if a gunsmith or service-center wants to inspect it completely, as a result.

Next steps, in order:

1. If there's a good gunsmith in the area, talk to them first. Maybe parts are available and avoiding shipping is less hassle. Replacing the broken parts doesn't require special tools, but it is moderately tricky and easy to screw up (as a visual examination of the trigger group can confirm).
2. If not, contact Wolverine Supplies since they're the warranty/service center, and have probably seen this kind of damage before, and know what parts they can get.
3. If that doesn't or can't work for some reason: there are other gunsmiths which might do the work. The bigger stores often have one or two, and there are a couple specialized shotgun shops who may, or may not, want to deal with this.
4. DIY replacement: if parts haven't been sourced by this point, there are several places to try. DoctorDeals and GunPost sellers might have a full trigger group, for a price. Western Gun Parts may be able to find them (but aren't in stock). You might be able to order the key parts from a US retailer like Brownells or Numrich (GunPartsCorp) but I can't confirm.

[u/Master_Chip1545 → u/PM_me_ur_TT-33]

Or consulting with a gunsmith?