Optimizing the 870 as a long-term survival shotgun.

[Synchronizor]

I had a conversation a while back with someone who was looking for a versatile survival shotgun for prepping, and it got me thinking about how the 870 would fare in that role.

Along with the shotgun itself, a prepper should also tuck away a couple sets of replacement parts for long-term upkeep. In a survival/SHTF situation, this upkeep may well have to be performed in a very primitive setting; no workbench, vise, specialized tools, or even electricity. Most of the 870’s small parts (or part groups) are readily replaceable by hand, or with very basic tools, but there are a couple things that normally require some specialized tools to work on.



The first is the shell latches, which are usually staked in the 870’s receiver. Now obviously, there’s nothing functionally wrong with staked shell latches; they make take-down and reassembly simpler, and do not break or wear out very easily. But in the event they do need to be replaced, doing so requires a fair bit of know-how and some specialized tools, and the process will mar the finish inside the receiver.

My thought is that, when building a shotgun for this type of role, it may be advantageous to simply unstake the shell latches. I've heard of old or well-used 870s that have had one or both shell latches come loose, but when the gun is put together, the front trigger pin and trigger assembly holds them in place and everything works just fine. Unstaked shell latches would complicate assembly, but not overly so. As long as they stay put and function properly when the gun’s together, they would be far easier and faster to replace when needed.



The second item is the ejector spring. Now yes, I've heard the detractors who point out the riveted ejector spring, claiming it to be some horrible Achilles’ heel, and the 870 should be avoided because of it. That’s all bunk obviously; those springs rarely break, and even if they do, almost anyone with a couple specialized tools can replace the spring and re-peen the rivets in a matter of minutes.

Still, in a survival situation where your workbench is limited to a screwdriver, an Allen wrench, and a flat rock; a broken ejector spring becomes more of an issue. The gun will still feed and go bang just fine without a replacement spring, but rapid shooting would become unreliable.

Ideally, this could be improved by replacing the rivets with screws, but I've never heard of anyone trying this. Tapping the receiver wall without having to go all the way through would be tricky, and the ejector may have to be modified to accommodate the screw head. In a real survival situation, I suppose the receiver could be drilled completely through and the spring held on with plain pop rivets, but it’s not an ideal solution, and would still require some means of drilling.

Other ideas I had involved a custom, tool-less ejector/ejector spring unit, or a custom bolt with an integrated, plunger-style ejector. Obviously, either of these would be quite an involved project, and ensuring reliable feeding and ejecting could be tough, so I haven’t really spent much time on those concepts.



Anyway, I wanted to see if y’all had any input or other ideas on this. I’m not quite pessimistic enough to get into long-term prepping, but I do believe in the value of being prepared; and as an engineer, I’m always thinking of ways to improve or adapt a design. Apart from survival/prepping, these modifications might also be desirable for the owner of a really high-use 870 who simply wants to be able to do all their own parts replacement without a lot of fuss.

[stoneyman2]

Apologies for replying to an old post, but I'm concerned about the same repair issue. Has anyone yet found a way to replace the rivets with screws? I imagine it can be done but may take custom machining?

[Synchronizor]

I did come across a fellow on another forum who had replaced the front ejector rivet with a small machine screw, and the gun seemed to function fine. So it can be done. However, having thought about it some more, I'm not sure replacing the rivets with screws would actually be the best way to go. There's a reason well-designed guns don't use many threaded fasteners. They tend to back out under recoil, causing malfunctions or simply getting lost. I know Mossberg 500-series shotguns have had issues with their ejector screws coming loose and falling out.

Rivets are more reliable and durable than screws, and they'll never come loose under recoil. If an 870's ejector spring breaks (which really isn't that common a problem), the riveted ejector is still capable of ejecting shells by itself (working the same way as the ejectors in semi-auto shotguns), so the gun can continue to function. If you replace those rivets with screws, and one or both of those screws happen to fall out or break, not only can you lose your ejector spring, but your ejector won't be able to function. And on an 870, the ejector is what keeps the barrel indexed, so you won't just see ejection failures, the bolt would be unable to reliably lock into battery, and the whole gun could become a paperweight. Simply put, replacing those rivets with screws would make the entire gun less durable and less reliable.

The way I see it, your prepping time and money would be better spent ordering some replacement ejector parts and a basic set of tools for installing them. A rivet cutter, a peening tool/punch, and a hammer should let you replace a broken ejector or ejector spring on pretty much any hard, flat surface. It wouldn't look super-professional if you had to install new rivets (replacement rivets are normally ground down flush with the receiver and finished over for cosmetic reasons), but it would function just as well as a factory/gunsmith repair.