It’s as if Lego made a shotgun. You snap some parts off, put some on, swap barrels, and your duck gun is a deer gun. Or a turkey gun. Or a home-defense gun or a tactical riot gun. You can change the stock, fore-end, and pad of Mossberg’s Model 500 Flex pump action in less than two minutes, without tools. Available in 11 base models, with 16 accessory parts, the Flex represents the ultimate expression of Mossberg’s shooting-system approach.

Having tied the company’s success to the Model 500 in 1962, Mossberg has since marketed its budget pump to be the one gun a shooter could use for every conceivable purpose. Over the years the company offered accessories and countless extra barrels to make the 500 extra versatile.

With the Flex, which comes in both the 500 and its military counterpart the 590, changing the gun’s furniture becomes as easy as switching barrels. The project started six and a half years ago when a Mossberg employee posed this question: “Wouldn’t it be great to be able to come home from duck hunting and switch your gun for home defense?”

Pick a Part, Any Part

Instant switching of parts is possible via the Flex’s TLS (tool-less locking system). The biggest design challenge lay in making a stock that could be removed and replaced fast without compromising strength. Mossberg engineers replaced the standard through-bolt in the stock with a zinc spline (ridged socket and coupling). A bolt on top of the stock head locks the spline. Pull the bolt up, turn it 90 degrees, and the stock pulls off. The fore-end snaps on and off a bracket staked to the action bars by means of a spring latch. Another latch holds the recoil pad in place, and it pops off when you push a recessed button.

Because the military expressed an interest in Flex, the guns have endured strenuous testing. “They were carried, dropped, shot a lot, and put through other tests to simulate active-duty use,” says Mossberg’s Bill Lutton.

The guns have also survived contact with the general public. Demo models were put together and taken apart hundreds of times at trade shows without failure. The connectors on my test Flex functioned well. The stock joint felt rock solid. Like all Mossberg products, the Flex seems inexpensively made, but don’t underestimate it: Mossberg has built its brand with affordable, durable shotguns; there are currently 50,000 to 70,000 Model 590s in military service.

At the Range

The Flex weighed a little over 7 pounds, a bit more than some 500s. It handled just the same as any Model 500, although the fore-end was a tad bulkier than normal. All the guns have Accu-Choke interchangeable choke tubes. It cycled slickly out of the box, as I found at the skeet range.

I switched parts to make a tactical gun and fired the Flex with Federal’s FliteControl buckshot loads. My gun was one of the versions fitted with the adjustable Lightning Pump Action trigger. It had a pull of a little less than 3 pounds as set at the factory, making it easy to place the buckshot loads precisely on target.

Complaints? Many of the Flex barrels are ported, but the recoil reduction is slight and the trade-off is cleaning ports.

Eleven versions of the Flex, all in 12 gauge, range from $593 to $826. A Flex would be perfect for kids; it is priced right and the pad, stock, and barrels can grow along with your son or daughter.

Most people currently buying guns are using them to shoot for fun at targets, milk jugs, zombies, whatever. Going to the range is bound to put them in contact with hunters. With the Flex, they have a gun that’s easily convertible to hunting if they want to give it a try. For that reason, the Flex could be good for all of us.

Photo by Gorman Studio