By Jeff Johnston, Shooting Illustrated

Gun manufacturers aren’t going to love me for writing this, but you don’t have to buy a brand-new shotgun for your home, shop, truck or boat when there are thousands of them in great condition on used-gun racks everywhere. You can pick one up for a song and turn it into an ultimate self-defense shotgun with a few simple mods. Here’s how:

Terry Summers owns Tiger Pawn on Main Street in Ada, OK. There’s a pawnshop or two like it in many towns across America. Summers sells a little of everything: Electronics, TVs, computers, chainsaws, guitars and tools, but he makes most of his money on guns and jewelry. Sure, he tends to turn over more Hi-Point pistols than HKs, but in shotguns he says the guns he sees most are Remington 870s and Mossberg 500s—both excellent choices for home-defense.

Sure, most of these are run-of-the mill, do-it-all hunting guns, but the reality is, blued steel and walnut stocks are just fine, if even better than synthetic stocks for most home-defense applications. After all, synthetic (another name for molded plastic) became all the rage for hunters and soldiers who routinely abuse their guns and expose them to harsh elements. A wooden-stocked gun kept in your house will last forever; same goes for blued steel if you run an oily rag over it occasionally. So, don’t let it bother you in the least if the slightly used shotgun you see on the shelf isn’t all “tactical black.” As long as the metal looks good and the gun functions, be ready to snap it up.

“I might buy the gun for $150” says Summers, “If it’s a newer, cheaper model, then sell it for $250,” he says. I don’t blame him for making a profit. He’s the one carrying the FFL and providing a storefront. But I’d also try to get him down to $225. If he won’t come off it, I’d see if he’d take cash and a trade for something. You never know what personal likes a pawnshop owner holds, and they’re in the business of wheeling and dealing.

Next, either know what the gun you are seeking costs new or look up what it’s going for used in the “Blue Book of Gun Values.” Just be aware that the pawnshop owner may not care, as he knows what he has into the gun and knows what he has to get out of it.

Before buying, however, check under the hood to make sure it’s not a lemon. You can ask about a warranty, but most pawnshops won’t offer one on a used item. Some will say something like “If it doesn’t work, bring it back.” Next, bring a flashlight into the store to shine light into the action to inspect the barrel for rust. If you are worried about it, pack several dummy rounds and see if you can load it and work the action to make sure it loads and feeds properly. If the shotgun looks and feels good, it probably is. It takes a lot of abuse to break a Rem 870 or a Mossy 500. Finally, see if there are any choke tubes that come with the gun. Then you’ll have to fill out the form 4473 and undergo the background check. ATF willing, you should soon be the owner of a new-to-you shotgun—for hopefully around $200.

Take your new (to you) shotgun home and test fire it immediately. If something is not working properly, record the problem if possible so you can show the pawnshop owner when you bring it back. Chances are, though, it will run fine.

Now, here’s where you must decide if this gun is going to be a do-it-all hunting and home-defense shotgun, or a dedicated home-defense gun. We’re going to assume it’s at least a combination of the two. Should your pawnshop find come with a longer barrel (22 inches or more), you would be well-served to either search online for a shorter replacement barrel or find a local gunsmith to trim it down. Bear in mind that new 18.5-inch barrels are around $100 from the manufacturer, so a used version might cost less than trimming that longer barrel.

I like shotgun barrels in the 20-inch range, but before you make any changes, buy a magazine-extension tube of your choice and install it. (I am partial to the two-shot version by Wilson Combat, available for under $50). You don’t want the barrel shorter than the magazine tube with the extension installed, because it’s a waste of potential barrel and velocity. So, make sure the barrel is even with or slightly longer than the magazine tube.

Next, order a sidesaddle-type receiver-mounted shell carrier and a flashlight mount on Amazon like the TufForce 1-inch Tube Mount. Then buy a magnetic, fiber-optic front sight from Hi-Viz. All of this will cost around $60, and these important accessories would be needed for a new shotgun, too.

After installing the above items and adding a flashlight, give it a good oiling and you can call this project done. You’ve just bought and built the ultimate home-defense gun for well below retail, and you can rest easy at night knowing that. Now, with the savings from your secondhand home-defense gun, invest in some quality defensive ammunition for it, and look into dedicated training. Why not make the most of the money you’re saving by buying a used shotgun?

Thanks to Shooting Illustrated for this post. Click here to visit ShootingIllustrated.com. Better yet: Click here to subscribe to SI’s free newsletter. Click here to follow SI on Facebook.