Disassembly Guide: Mossberg MC1sc (90% Glock, 10% Roll Pins!)

Do you like the simplicity and reliability of Glocks, but hate Austria or rectangles?  Good news, there’s another US-made Glock on the market, courtesy of Mossberg!

Hot on the heels of the successful Ruger SR series, and by that I mean almost a decade late, the MC1 pistol is a bit of a head scratcher trying to butt its way into an already crowded market.  To be completely honest, I’ve been so busy with other things in the past year that I hadn’t even heard of this pistol until I ended up with one in my hands.  The general reaction from friends and customers has been “wait, Mossberg makes a pistol now?”

MC1 Profile

Have you heard of that new Mossberg pistol?

Part 1: Field Strip and Slide

  1. Field strip.  Retract the slide part way, push the button in the back plate in and pull the back plate down to remove it.  The striker assembly will come right out, and the slide will come off the front as usual.  No dry fire required.  The recoil spring is a nested captive assembly like most subcompact pistols these days.
    MC1 Slide Button

    Push button…

    MC1 Striker Removal

    …receive striker assembly.

    MC1 Field Stripped

    If it walks like a duck and quacks like a duck…

  2. Disassemble the striker.  Exactly the same as a Glock, you can use the slide as a jig.  Compress the striker spring, remove the spring cups and pull the rest apart.
    MC1 Striker Disassembly

    Every Glock armorer’s favorite trick!

    MC1 Striker Parts

    Will maritime spring cups fit? Probably, for the three people asking that question.

  3. Drive out the extractor roll pin.  I recommend driving it out bottom to top and stopping as soon as the extractor shifts to show the pin is free.  It’s annoying to get started if you drive it fully out.  Also, the extractor spring is pretty stout!

    MC1 Extractor Pin

    Tiny roll pins, hooray!

  4. Remove the extractor and striker block.  The extractor pivots out and uses a lug to protect against blowouts similar to the XD series and many other modern pistols.  The striker block plunger is retained by the extractor in a similar fashion to Glocks.

    MC1 Extractor Parts

    Blowout protection lug is a nice little upgrade.

  5. Drive out the rear frame roll pin.  Unlike the Glock’s polymer pin, the MC1 uses a roll pin to retain the ejector housing.  Conveniently, if you have a roll pin starter for doing AR-15 bolt catch pins it’s perfect for this.

    MC1 Rear Frame Pin

    Less annoying than the extractor pin, by far.

  6. Knock out the trigger pin.  Again just like a Glock, the main pin is grooved and retained partly by the slide stop.  The same tricks apply as the Glock pin: wiggling the slide stop can help free it up.MC1 Front Frame Pin
  7. Lift out the locking block.  Underneath we have a trigger return spring that nests into the underside of the locking block and the slide stop with its more or less attached spring.

    MC1 Return Spring

    Thankfully, the spring stays put which makes reassembly much easier.

  8. Remove the ejector housing and trigger.  Pure Glock here.  The shape of the trigger is a nice minor upgrade over stock Glocks though.MC1 Trigger Parts 1

    MC1 Trigger Parts 2

    I don’t imagine that those $30 fancy connectors work here, but you can try.

  9. Fish out the trigger return spring.  Seems like Mossberg went with the more recent Glock design akin to the old New York return springs, which snaps into a little cutout on the ejector housing pictured here.MC1 Connector Spring
  10. Remove the connector.  Only if you REALLY have to, because Mossberg crimped the edge of the leg that inserts into the ejector housing and it’s a pain to remove.  Otherwise, just like a Glock – just more annoying.

Additional stuff.  The magazine release is retained identically to Glocks, so if you really want you can get a hook down in there and shove the spring out of the way.  It’s not reversible or anything fancy, as far as I know anyway.  The factory magazines are a smoked translucent plastic and come apart like normal mags, i.e. pushing in the baseplate lock and pulling apart.

MC1 Profile 2


There’s not a whole lot to say about this little guy, except that it’s a surprisingly solid, comfortable and inexpensive little Glock copy.  The handful of minor upgrades like the excellent slide serrations and flat trigger are welcome, especially for bargain hunters who may be able to find these pistols under $300 from some outlets.  Another plus is compatibility with Glock 43 magazines, including aftermarket parts like the 12-round ETS branded clear polymer magazines – it is however worth mentioning that when they’re in stock Mossberg’s official store sells spare mags of either flat baseplate or finger extention varieties for around $20.

Speaking of compatibility, the MC1 uses Sig Sauer dovetails for sights so you have alternatives to the overpriced factory tritium option.  No complaints from me about the standard 3-dot sights though, they’re quite good for a pocket sized pistol.

While it’s perfectly feasible to use Glock striker and striker block plunger springs my experiments didn’t result in much improvement to the trigger pull, which is adequate but not stellar.  The same tuning tips should apply to this critter as any recent generation Glock which uses the new style reset spring.  Polish work will smooth things out, but the bulk of the weight is in the connector angle, sear engagement and striker spring.  The latter is already surprisingly modest.

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