Apex Gunsmithing
23Apr/18

Disassembly Guide: Winchester Model 50 12 Gauge

The last of an era, the Winchester Model 50

The last of an era, the Winchester Model 50

The year is 1950, and Winchester Repeating Arms company looks on with envy while Remington, Browning and even Savage pump out their versions of the most popular semi-automatic shotgun of all time: the Auto-5.  Winchester has done well enough in the pump shotgun market with their John Browning derived designs: the Model 1912 (shortened to simply Model 12) had become the household name in slide actions which Remington and the rest chased after and the cowboy classic 1897 was just now reaching the twilight of its production.  The autoloader itch remains unscratched, however, after the schism between the company and Browning himself over four decades earlier.  While the other American gunmakers enjoyed licensed and even military contract production Auto-5s, Winchester stumbled about producing the famously terrible long recoil operated Model 1911 shotgun, not to be confused with the pistol, which limped along for ten or so years before being quietly shuffled under the rug in the early 20s.

With their first autoloading shotgun in the post-Browning era a spectacular failure caused in part by their necessary dodging of Browning's patents (which Winchester helped him develop, ironically) the company took a long break from the whole affair.  Instead, the Winchester company continued its dominance of pump shotguns through the inter-war period with some competition nipping at their heels from Remington and later Ithaca, as well as developing the Model 21 double barrel.  In both cases, Winchester offered a vast array of custom options and essentially made their guns to order for anything beyond the base model.  Their single shot break action Model 37 turned into a smash hit, even seeing US Military acceptance with the famous flaming bomb emblem.  Around the same time, they became the de facto leader in smallbore pump actions with the Model 42 in .410 bore, now highly valued collector pieces.

Winchester tried a long recoil shotgun again, and it was terrible.  The Model 40 was produced for only two years and it was so bad they issued recalls during World War II.  The all around poorly designed mess of a shotgun was again quietly buried while Winchester converted most of their tooling to supporting the war effort.  That last bit would turn out to be important and any fan of US small arms of World War II will recognize the name David Marshall "Carbine" Williams, the father of the "tappet" short stroke gas piston design from the US Carbine Caliber .30, M1.  Though he's known almost exclusively for that famous work and a film about him starring Jimmy Stewart, he was a prolific designer behind the scenes at Winchester and remained with them throughout the 1950s until his health declined in the 1960s.  Prior to his involvement with Winchester, however, Williams was responsible for a key element of the Colt Ace .22LR conversion for the government model 1911 pistols: the floating chamber.  It's here that we merge back into the story of our gun today.

In 1950, a team at Winchester was tasked with adapting some elements from a patent sold to the company by one of John Browning's sons, Jonathan Edmund Browning, into a sporting shotgun.  Williams was added to the team and soon reworked his 20's era Colt Ace floating chamber concept to the substantially larger 12 gauge shotgun form factor.  The result was the Model 50, which began its relatively short production run in 1954 and after about 190,000 shotguns was discontinued in 1961.  The Model 50 is a throwback to a time before space age materials, hollow plastic stocks, cheap stampings and MIM parts.  Everything is machined, including the aluminum trigger housing.  All in all the gun was reliable, soft shooting and could be adjusted somewhat for different loadings by adjusting the recoil plug that tensioned the mainspring.

So why didn't it take the world by storm?  The answer, in part, is simply bad timing.  The early 1960s ushered in the era of gas operated shotguns and space age materials.  With the exception of perhaps two popular long recoil designs, shotguns rapidly shifted away to gas powered and in this transition Remington jumped way, way out in front with the Model 1100.  The Winchester 50 was in many ways the last of an era, and despite its positive elements it did bring along some baggage.  The fixed two shell capacity was lacking in a changing market that wanted three, four or five shell tubes or at least some way to expand it.  The adoption of interchangeable chokes began in earnest around that time as well, which the Model 50 lacked.  Most importantly perhaps, it was a general pain in the ass to clean and maintain.

Winchester's answer was to modernize the Model 50 with the evolved form, the Model 59.  Using new space age materials and lots of ad space, they reworked the gun into an aluminum receiver featherweight with a fiber wrapped barrel, slapped some scrollwork on the sides and gold plated the trigger, and finally introduced their own Versalite interchangeable choke tube system.  All of this netted them even poorer sales and a five year run, ending unceremoniously in 1965.  Its death knell would be the end of the floating chamber.

One last tidbit I'd like to quote from an episode of This Old Gun about the Model 50:

Because it was a short recoil gun, and the barrel only moved rearward a short distance, its reliable operation was highly dependant on the shape of the operating cam that would unlock it.  Williams, who had basically invented the operating system for the gun pulled the design for the cam pretty much out of his head, without a lot of mathematical calculations.  And when he had it about where he thought it should be - and this is a story told to me by a former Winchester designer who was there - so they went down to the range and fired a few shots with this thing. 

Williams was doing the shooting, and immediately after firing a few shots they opened up the gun and they could see bright spots where the cam had rubbed against its opposite surface.  And he'd say well I think we should take a little more off right here, and off to the tool room they would go and mill it down a little bit, then back to the range again.  This went on for quite a few times and they deliberately left the bolt a little soft so they could see where it was wearing.  Finally they got to the point where Williams was satisfied with the marks that were left on this soft cam [track] and said, 'alright button it up, that's how it's going to be!'

-- Mike Parker


Part 1: General Disassembly

Now that the history lesson is out of the way, or you've impatiently skipped down this far, let's dig in!  The first few bits are easy.

  1. Slide off the forearm.  Unscrew the captive knurled bolt until it frees up the forearm to slide forward and off.

    Short mag tube, big retainer bolt.

    Short mag tube, big retainer bolt.

  2. Remove the barrel.  Rotate the barrel 90 degrees to unlock the interrupted thread and yank it forward, off the receiver.

    Twist and pull

    Twist and pull

  3. Pull the floating chamber out.  Pull the bolt handle back a bit until the bolt unlocks, then the floating chamber will pull out the front.

    Unlock and yank it out.

    Unlock and yank it out.  Note the extractor cut.

  4. Knock out the trigger guard pin.  The assembly pivots up at the back and you'll have to push the carrier latch button to give it room to move.

    Pushing the latch button gives room to tilt

    Pushing the latch button gives room to tilt

The major components of the Model 50.

The major components of the Model 50.

Not Pictured: The magazine spring and follower are retained by a cap pinned in place, clearly visible in the photos.  It's a mildly stubborn pin and the short tube still has a stout spring inside it so be wary.


Part 2: Receiver Disassembly

Now the fun begins.  We're going to work back to front because of the recoil spring down in the stock.

  1. Take off the buttplate.  Nothing special here, just keep the screws matched for consistency.
  2. Pop out the retainer spring.  This thing is a pain later, but a flat screwdriver will get it unhooked right now.

    Annoying spring retainer

    Annoying spring retainer

  3. Unscrew the recoil plug.  The spring behind this plug is decently strong but shouldn't go into orbit unless you really mess up.

    The retainer is one of the few aluminum parts!

    The retainer is one of the few aluminum parts!

  4. Knock out the cam pin.  Carefully line up the hole in the handle slot with the cam pin and push it out via the tiny hole on the opposite side.  Do this upside down to avoid stuff falling out.

    Wiggle the bolt up and down if it sticks a bit

    Wiggle the bolt up and down if it sticks a bit

  5. Yank the bolt tail out.  The heavy tail/follower arm will slide out of the stock tube easily.
  6. (Optional) Unscrew the stock tube.  You'll need a jumbo screwdriver or something to span the cuts in the tube, but otherwise it just unscrews like you'd expect.

    That's... sturdy.

    That's... sturdy.  Note the slight arc and the hump facing upwards (toward the bolt)

  7. Dump out the handle and plate.  Charging handle and the cam link plate on the opposite side (they sandwich the bolt) will basically fall out.

    Bolt, charging handle, reinforcement plate, and cam pin.

    Bolt, charging handle, reinforcement plate, and cam pin.

  8. Remove the bolt group.  Press in the latch button and lift out the bolt.

    The back side of the bolt opposite the charging handle, note the plate position.

    The back side of the bolt opposite the charging handle, note the plate position.

  9. Unscrew the latch pin.  The carrier latch has a partially threaded pin and it may be a bit snug even once unscrewed completely.
    Tiny part threaded pin again

    Tiny part threaded pin, covered in gunk.

    The latch is its own button, one milled piece with a spring and pin

    The latch is its own button, one milled piece with a spring and pin


Part 3: Bolt Disassembly

Nothing too tough here, just a bit fiddly and having to fight the ejector spring.

  1. Wrestle the ejector out.  You can compress the spring against a flat surface and coax it out of the slot a bit, then encourage it the rest of the way with light taps onto a small diameter punch.

    It requires a little coaxing, but don't bend it.

    It requires a little coaxing, but don't bend it.

  2. Remove the firing pin.  With the ejector out, the retainer pin is exposed and pushes right out from the half blind side.  Quarter blind?  Whatever.

    Pins and springs!

    Pins and springs!

  3. Knock out the extractor pin.  This has to come out bottom to top since it's partially blocked by the bolt.  Well done Winchester, having a pin walk and fall out downward into the action is bad news bears.
    Sneaky little pin

    Sneaky little pin

     


Part 4: Trigger Group Disassembly

While vexing at first glance, this trigger group is really clever and has the craziest hammer spring of all time!

  1. Coax out the carrier.  Wiggle and lift the carrier away from the housing, then poke at the carrier spring's long bottom leg which sits in a small cut to help retain the carrier.  The spring will do spring things once free.

    One of two really wonky springs in here.

    One of two really wonky springs in here.

  2. Wrangle the trigger spring.  Let the hammer down all the way.  That long crazy leg of spring is the trigger return spring.  Get it up and over the wall of the housing and it will free up the trigger and sear pin.

    This leg retains the trigger pin and tensions the trigger return.

    This leg retains the trigger pin and tensions the trigger return.

  3. Remove the trigger and sear.  Push out the headed pin and dump out the trigger and disconnector.

    Simple trigger setup

    Simple trigger setup

  4. Pull out the hammer spring.  That crazy spring is actually the hammer spring, surprise!  Lay the hammer all the way back inside the housing and line the short leg inside the hammer up with the tiny slot in the housing to remove it.

    What in tarnation

    What in tarnation

  5. Pull the hammer pin and hammer out.  The hammer pin has a short end toward the blind side and a long end that the hammer spring rides on.

    A spring of many talents?

    A spring of many talents?

  6. Plunger down, safety out.  Use the tiny pin hole on the bottom of the safety, and possibly the carrier spring as a poker, to push down the plunger that spring loads the safety.  BE VERY CAREFUL not to shoot the plunger into space.
    That's tiny.

    That's tiny.

    Very, very carefully

    Very, very carefully.  The carrier spring is a perfect fit for this.

    Traditional setup, but not reversible

    Traditional setup, but not reversible

     


Reassembly Tips and Tricks

There are a few things to keep in mind when reassembling the Model 50.

  1. The link arm can't go in upside down.  So don't worry about messing that one up!
  2. Lining up the bolt, handle, plate and arm is fiddly.  There's no great way to do it, but without the recoil spring behind it you can nudge the pieces into alignment without much trouble.  Patience!
  3. The charging handle and reinforcement plate sandwich the bolt, and can't be assembled wrong.  You can put them in the receiver wrong and fight it a bit to get them in position, but the pin hole makes sure the parts are lined up right.
  4. It's easiest to start the trigger pin, then put the trigger spring leg in place over it.  That way you can push the pin in place with the spring riding it, and won't have to fight the spring later.
  5. There's no good way to reassemble the carrier and spring.  Seriously, it's a pain.  You can try to keep the short leg in its hole and shove it all together, maybe you'll get lucky.  It's finnicky.
  6. Press the carrier latch button when inserting the trigger group.  Just like when removing, you need that latch out of the way to tilt the trigger group enough to get it there.  It snaps back to position once it's seated.
  7. DO NOT THREAD THE RECOIL PLUG TOO FAR IN!  The spring will coil bind and cause various problems, not the least of which is failure to lock open.  If you reassemble your Model 50 and the bolt won't lock open, you went too far.  Back it off until the flat top of the cap is at least flush with the cuts in the stock tube, no further.  Backing it a half turn or more out beyond that won't hurt.
  8. That spring retainer is the worst.  That is all.

Design and Function

The Model 50 is a short recoil, locked breech design.  Unlike the Auto-5 which has the entire barrel travel roughly the length of a shell during recoil, the Model 50 has a fixed barrel and the unique floating chamber which only travels a short distance during recoil.  The tipping bolt locks into the steel floating chamber as its locking surface, so those two components travel together until the bolt unlocks via the cam pin pulling the bolt downward in the back.  The bolt has a spring loaded firing pin as you'd expect, but also a spring loaded ejector which strikes the back of the receiver and sticks out of the bolt to kick empties loose, then retracts as the bolt travels forward again so it won't snag the feeding shell's rim.

Locked position. The straight section provides dwell time

Locked position. The straight section provides dwell time

Unlocked position. The cam pin pulls the rear of the bolt down via the angled track.

Unlocked position. The cam pin pulls the rear of the bolt down via the angled track.

The trigger assembly is mostly conventional with the exception of the crazy hammer spring which acts as the hammer spring, trigger pin retainer and trigger return spring all at once.  The trigger is a standard primary sear with a separate spring loaded disconnector or secondary sear that pivots off of it.  The carrier latch is a cartridge stop on the front side and the latch on the back side, which holds the carrier in the down position normally until you press the button.  The bolt locks open against the carrier dog, which is the pivoting bit pinned to it that the spring hooks to.  The bolt resting against the carrier dog tries to force the carrier down in the back, up in the front, but the latch blocks it in the front.  Hence, when you press the button the bolt releases and the carrier jumps up to feed the next shell.

Conventional primary and secondary sear arrangement, like an AR-15

Conventional primary and secondary sear arrangement, like an AR-15


Conclusion

I was stoked to get my hands on this Model 50 at a local auction, but at the time I only knew a tiny sliver of the history of the gun.  In the writing of this guide and the history accompanying it I really developed an appreciation for the clever design, its development history, and its place in history as the last hoorah of the recoil operated shotgun era.  Of course decades later a new era of recoil operation would emerge with the likes of Benelli and their inertia drive, but there's just something about an all milled steel (and two aluminum bits) classic 1950s shotgun that evokes that old school walnut and steel sportsman in me.


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