Best way to build an 870 from parts?

[Malpaso]

I'm looking for a winter project, and thought I might try building an 870 from parts. This will be a personal protection gun. I'm a basement revolver smith, far from a professional. This will be my first shotgun project.

The only thing for sure at this point is I plan on going with magpul furniture

Here are my questions.

What should I look for in a receiver? Is one model better to build on than another?
What is a good source for that receiver?
What is a good source for parts? I want to get the metal trigger group. I usually buy from Brownells. Is there a better place?
What common problems don't I know about yet?

[DaveC]

I'm not sure where in New England you are, but I do know that tube magazines are limited by the laws of the Commonwealth of Massachusetts... My "should done this instead" 870 would be one of the 7-shot 20-gauge models. I wouldn't be able to own it in MA.

I'd think for a project gun, you should try to get an old, used 870. There are bound to be very many in your "neck of the woods" on used gun racks. A Wingmaster, perhaps? If you are going to parkerize the finish, why not start with an old, cast off, surplus police shotgun? I got a Pontiac, MI S&W/Howa 3000 with exterior wear, coffee and donut stains <j/k> for a song here in Texas where I reside. The Texas state prisons just sold off a whole bunch of hideously ugly, battered beyond recognition prison guard guns. Outfits like J&G Sales, Alan's Armory and some others have 'em periodically. Something like that would give you a worn but serviceable receiver to tinker with, or reparkerize/refinish or whatever.

Brownell's? Sure! Numrich? Sure! How about Remington factory parts? Sure!

Good luck with your shade-tree gun tinkery project. Folks hereabouts would love to see pictures when you are finished!

[Malpaso]

I have a MA Class A License to Carry, so I can own a large capacity shotgun.

I already own an 870P, so I don't want to buy a complete gun and swap parts. I will use it as a model to make sure I put all the parts in all the right places! I'm looking to get a bare receiver and learn how to build it from the ground up. I like your idea of the Wingmaster. I've seen some Wingmaster receivers on Gunbroker fairly inexpensive. I wasn't sure if there was a "go to" supplier of things like that. I will check J&G and Alan's. I've already started a price list on Brownells, including the magazine, sear and carrier springs, Vang safety and follower and Magpul stock and fore-end.

As far as Parkerizing, that's out of my skill set. I may try a rattle can paint job though. I will definitely post pics when I'm done.

Thanks.

[Synchronizor]

The 870 isn't an AR-15, building an 870 from parts would be only slightly more complicated than putting one back together after a field-strip. It's something you could do in an afternoon. And unlike other platforms, there's really not that much you can do to customize an 870's action. Yes, you can choose your preferred furniture, sights, and other accessories, but the core gun parts like the receiver, bolt, and trigger plate assembly are for all intents & purposes functionally identical across the range of 870 models. Your options are primarily differentiated by finish, materials, and other things that have more to do with cosmetics than function.

Plus, unless you scrounge up everything on the used market, you'll pay a lot more buying parts separately than you will starting with a complete gun and customizing it. New-manufacture receiver assemblies from Remington are $250 - $300; about the same as a fixer-upper 870 Police with all its parts.

To answer your questions though:

What should I look for in a receiver? Is one model better to build on than another?

I'm assuming you're looking to build a 12ga Magnum here, so correct me if I'm wrong.

Excluding some specialty variants with nonstandard 3- or 6-round magazine tubes, the only differences between 870 receiver assemblies are the finish, engraving, whether or not the magazine tube is dimpled, and whether or not the top is drilled & tapped. Otherwise, they're identical in terms of construction, parts, and build quality. Since any receiver that isn't drilled & tapped can be very easily, and engraving adds nothing to a defensive arm, the finish and magazine tube will probably be your biggest considerations (and maybe not even the finish, if you're just going to strip & refinish this when you're done). A magazine extension can be added to any receiver with any magazine tube, but if you have the option to get a receiver without the dimples for the new-style internal-ratchet spring retainers, it won't need any further modifications.

What is a good source for that receiver?
What is a good source for parts? I want to get the metal trigger group. I usually buy from Brownells. Is there a better place?

The best place to start if you want new parts is Remington's parts price list. Sometimes you'll find better prices on 3rd-party websites, but Remington's parts department always has more options to look at, and you're best off researching what you want there before shopping around. More info on that here.

[Malpaso]

Synchronizor - that was a great write-up, thanks. The comparison to the AR build really put things in perspective, as I have done two of those. After everything you pointed out, I think my best bet is to get a used, decent Wingmaster. I haven't seen a Police around here. Looks like I can probably get around $100 (maybe more) for the takeoff barrel and stock/fore end. I started looking around at prices and for the little extra I might pay, I can pretty much one stop shop at Brownells.

[Malpaso]

Gun clubs are a wonderful thing. One member who owns a gun shop had a Wingmaster on consignment. Saw it last night, bought it. Went to our monthly meeting and sold the barrel, fore-end and stock to the trap chairman. Already placed a starting order with Brownells.

[Synchronizor]

Sounds like you're off and running. You'll have to post some pictures as your project progresses.