Smith & Wesson Model 59 and 5906 Magazines: A Buyer's and Compatibility Guide

If you've got a Smith & Wesson Model 59 or one of its later relatives, the magazine question gets confusing fast. Maybe you've shot one for thirty years and your originals are getting tired. Maybe you just pulled one out of a parent's safe and you're trying to figure out what feeds it. Maybe you've got a 5906 you bought as a police trade-in. Walking into a gun shop and asking for "an S&W 9mm magazine" is a good way to walk out with the wrong part.

The good news: there's a simple answer. The United Defense 15-round 59-series magazine is engineered as a universal-fit replacement across the entire S&W 59-series family — Gen 1 Model 59 (1971–1982), Gen 2 Model 459 / 559 / 659 (1980–1988), Gen 3 Model 5903 / 5904 / 5906 and the later 5946 / 910 / 915 (1989–1999) — plus the Marlin Camp 9 carbine (1985–1994), which was originally designed to feed from S&W 59-series magazines. One magazine, the entire family.

For Gen 1 Model 59 owners who specifically want the Italian-OEM pedigree, the Mec-Gar replacement is the historical alternative — covered later in this guide. But for most owners across the 59-series family, the universal-fit answer is the practical one.

Identifying your Smith & Wesson 9mm (still useful, even with a universal-fit answer)

Even with a universal-fit magazine available, knowing which generation pistol you have matters — both for troubleshooting (factory original magazines from one generation won't fit another) and for understanding what you're holding when somebody asks. Three generations of Smith & Wesson 9mms get lumped together in casual conversation:

The original Model 59 (1971 to 1982)

The original Model 59 is a first-generation S&W double-stack 9mm. The slide is marked "Model 59" on the left side. The frame is aluminum alloy with a steel slide. The magazine release is a push-button on the frame, behind the trigger guard. Capacity in the factory magazine is 14 rounds.

This was Smith & Wesson's answer to the Browning Hi-Power, and it helped kick off what the gun press later called the "wonder nine" category — a high-capacity, double-stack 9mm semi-auto built for service use.

Second-generation lookalikes: 459, 539, 559, 639, 659

Starting in 1980, S&W rolled out the second generation of its 9mm line. The Model 459 came first, followed by the 539, 559, 639, and 659. These pistols share the Model 59 silhouette but the internal magazine geometry was reworked. Capacity stayed at 14 rounds. If your slide is marked 459, 539, 559, 639, or 659, you have a second-generation pistol.

Third-generation S&W 9mms: the 5906 family

Smith & Wesson's third-generation autos arrived in 1989 with the 5903, 5904, 5906 (full-size, all stainless), the aluminum-frame 5906 variants like the 5946, and the later 910 and 915 economy variants. Full-size third-gen factory magazines hold 15 rounds. The 5906 in particular was the duty pistol for many American police departments through the 1990s and remains one of the most-encountered S&W 9mms in civilian hands today — the police trade-in pipeline of the 2000s and 2010s seeded a lot of these guns into the civilian market.

There's also a fourth generation colloquially — the compact 6904 and 6906, holding 12 rounds — which share the third-gen design at a different size. The compacts use a shorter magazine and aren't covered by the universal-fit 59-series replacement.

Bonus: the Marlin Camp 9 carbine

Worth knowing if you've inherited an unusual gun: Marlin produced a 9mm semi-automatic carbine called the Camp 9 from 1985 to 1994, designed explicitly to feed from S&W 59-series magazines. The Camp 9 is a relatively obscure carbine today, but enough were produced that "where do I find magazines for my Marlin Camp 9?" is a recurring question on gun forums. The answer is the same as for the S&W pistols above. The United Defense universal-fit magazine works in the Camp 9.

Compatibility at a glance

The short version, in one place:

The seven amber rows are all fed by the same United Defense universal-fit 15-round magazine. For Gen 1 and Gen 2 owners, that's a +1-round capacity bonus over the factory 14-round originals; for Gen 3 owners, it matches the factory 15-round spec exactly. The compact 6904 / 6906 is the only family member that uses a different magazine and isn't covered by this SKU.

The United Defense universal-fit 59-series magazine

For most owners feeding any S&W 59-series pistol — or a Marlin Camp 9 — the practical answer is the United Defense 15-round magazine we manufacture in-house. The engineering value here isn't subtle: factory original magazines from the three S&W generations don't cross-fit, but a purpose-engineered universal replacement does — one SKU covers the entire family.

If you own one S&W 59-series pistol and a Marlin Camp 9, this is the same magazine for both. If you own two different generations of S&W 9mm (a Model 59 in the safe, a 5906 in the drawer), this is the same magazine for both. The simplification is the value proposition.

For Gen 1 Model 59 owners: the Mec-Gar OEM alternative

Mec-Gar is an Italian magazine manufacturer that has spent decades as the OEM supplier for many handgun brands — including Smith & Wesson on later models, plus Sig Sauer, Beretta, CZ, Browning, and Walther. Their Model 59 replacement is the historical OEM-pedigree alternative for Gen 1 owners specifically, with build quality consistent with what S&W shipped originally and pricing in the $35 to $50 range.

The Mec-Gar Model 59 magazine is not a universal-fit design — it's specifically the original 1971 14-round factory replacement for the Gen 1 Model 59. If you have a Gen 2 or Gen 3 pistol, this isn't the right answer for you. If you have a Gen 1 Model 59 and you want the Italian OEM pedigree (and the 14-round factory-spec capacity rather than the +1-round universal-fit replacement), Mec-Gar is the answer.

The specific Mec-Gar Model 59 SKU is being added to our catalog the week of May 2026. Until then, browse the Mec-Gar brand collection for the broader Mec-Gar lineup, or contact us if you want to know exactly when the Model 59 SKU goes live.

Other sources (factory originals and surplus)

Original factory S&W magazines

Original factory Smith & Wesson magazines — Model 59, 459 / 559 / 659, or 5906 family, in NOS or genuine used condition — still surface periodically. Estate sales, gun show tables, online auctions, and parts dealers are the usual paths.

Pricing varies. NOS originals in the wrapper can run $60 to $100 or more. Used factory mags in honest, serviceable condition typically land closer to $35 to $50, depending on cosmetic shape and how thin the supply is at any given time. The 5906 originals are easier to find than the Model 59 originals (more were produced, more remain in circulation).

If you find an original, inspect the feed lips for symmetry, check that the follower moves freely under spring tension, and look at the baseplate for damage. A magazine that's been dropped on its baseplate hard enough to deform it is a magazine you'll fight forever.

Police trade-in and surplus lots

The 5906 was the duty pistol of many American police departments through the 1990s, and a major share of those pistols came back through the surplus and trade-in pipeline starting in the early 2000s. The supply isn't what it was a decade ago, but lots still surface from time to time. Some Model 59s also went into police service in the 1970s, though in much smaller numbers.

Police trade-in mags are typically used hard. Expect honest cosmetic wear, possibly weak springs, and occasionally a follower that needs replacement. Priced right, they're a good way to build up a stack of working magazines for range use. Plan to install fresh springs before trusting them for serious work.

Aftermarket options to approach with caution

A handful of other manufacturers have offered 59-series replacement magazines over the years. Quality varies. Some run fine. Some have feed lip dimensions that aren't quite right, or springs that lose tension after a few hundred cycles. After 23 years of selling magazines, the pattern we've seen is that for older, low-volume platforms like these S&W generations, the cheaper aftermarket options often don't justify the savings.

Source comparison — the honest version

You can also browse our broader Smith & Wesson magazine selection to see what's currently in stock for other S&W platforms, and our team can usually point you toward what's worth buying for a given pistol.

Loading, maintenance, and magazine care

If you're feeding a Model 59, 5906, or Marlin Camp 9 today, odds are at least some of your magazines have been around a while. Maybe decades. Here's what to look at before you trust them.

Reconditioning a long-stored magazine

A magazine that's been sitting loaded in a sock drawer since 1985 isn't necessarily ruined. It also isn't necessarily safe to load and shoot without an inspection. Take it apart. Look at the spring (we'll get to that next). Wipe the body clean inside and out. Check the follower for cracks or chips, and check that it slides freely without binding when you reassemble.

Replacing the magazine spring

Magazine springs lose tension over time, especially when stored compressed for years. A weak spring causes the same symptoms a lot of owners blame on the pistol: failure to feed the last round, slow to load, or rounds that don't lift fast enough to chamber.

Replacement 59-series magazine springs are still available from parts dealers. They're inexpensive and easy to install: drop the baseplate, swap the spring, reassemble. If a magazine is giving you trouble and the spring hasn't been replaced in decades, replace it before you start blaming anything else. We carry replacement Smith & Wesson parts for many older platforms; if you're not sure what fits, get in touch.

Cleaning the body, follower, and baseplate

Field-strip the magazine, wipe the inside of the body with a clean rag (no oil; oil collects grit), make sure the follower moves freely, and check that the baseplate locks back in place positively. That's it. There's no advanced procedure here. Most magazine problems trace back to dirt, debris, or fatigue, and a five-minute strip-and-clean catches most of them.

Frequently asked questions

Putting it together

Three things matter most when you're buying magazines for a Smith & Wesson 9mm of this lineage:

You can browse our pistols catalog on the site, or check our Smith & Wesson magazine selection for what's currently in stock across the broader S&W family. With fresh magazines and quality 9mm ammunition, a well-maintained 59-series pistol still shoots well after fifty years. If you'd rather pass the pistol along than feed it, our Sell To Us program buys collections and individual pieces.

One magazine, the entire 59-series family plus the Marlin Camp 9. The simplification is the value.