Masterpiece Arms 9mm Defender (MPA 30) Pistol

Masterpiece-Arms-MPA-30T from the Masterpiece Arms website

In this article, we’ll be talking about the Masterpiece Arms 9mm Defender. First, however, we have to discuss the…

MAC-10 — Predecessor of the MPA 30 Defender Pistol

“The Guns that Made the 80’s Roar”

If you grew up watching action movies from the 70s, 80s, and 90s, you’ve undoubtedly seen some variation of the MAC-10 machine pistol.  Originally designed in the 1960s by Gordon Ingram, it was intended to be paired with a Sionics brand suppressor for commandos to use in clandestine operations.  Its telescoping-bolt design and folding stock made for a weapon that was much more compact than the submachine guns of the era.

Being a specialized weapon, and one that was restricted in commercial sales by the National Firearms Act, the MAC-10 and its subsequent variants (even the semiautomatic ones) never achieved widespread use.  They, along with the TEC-9 and the Uzi, have been described as “the guns that made the 80s roar”, and are often more associated with criminal gangs than they are Special Forces soldiers.  The guns had spotty production by a variety of companies over the years (the Military Armament Corporation, Cobray, SWD, etc.), and sometimes suffered quality control issues.

Dual wielding Uzis

Regulation Woes

The guns originally were available in .45ACP and 9mm, with the .380 being added later.  All of them were, originally, open bolt, blowback operated, select-fire machine pistols, made of stamped steel.  Federal regulation repeatedly encroached on the already limited market these guns had; the Firearms Owners Protection Act of 1986 closed the NFA machine gun registry, so that no new machine guns could be made legally transferrable between private citizens, and the 1994 Crime Bill (with its attached “assault weapons” ban) limited magazine capacities to 10 rounds.  The entire MAC-10 family was almost legislated out of existence.

This changed around the turn of the century when Masterpiece Arms came onto the scene.  They introduced closed bolt, semiautomatic, and legal MAC-style pistols.  The .45ACP version used M3 Grease Gun magazines and was based on the MAC-10.  The 9mm one used STEN gun magazines and was based on the Cobray M11/9.

John Wayne shooting the MAC 10


Why STEN Magazines?

Some of you might be asking yourselves, “STEN magazines?  What?”  Younger shooters might not remember the decade of the ill-conceived “assault weapons ban”.  One of its provisions prohibited the sale of magazines holding more than ten rounds to anyone but government entities.  The only ones that could legally be sold to ordinary private citizens were those manufactured before the law was enacted in September of 1994.  These became known as “pre-ban magazines”, and given that the supply was limited, prices steadily climbed.  In 1999, for example, a 13-round magazine for a Glock 21 would cost something like $110.  A quality manufacture (Colt) 30-round AR-15/M16 magazine could run $50 or more.  Worse, affordable magazines were often junk.

Surplus magazines for the British STEN submachine gun were, at the time, cheap and abundant.  You could buy them in bulk, most of them liquidated inventories from the Second World War.  Nobody wants a MAC-style pistol that’s limited to ten rounds, so Masterpiece Arms wisely decided to utilize ones that were readily available to the public.

Then and Now

A lot has changed between then and now.  The so-called assault weapons ban expired in 2004, and quality magazines are readily available for most firearms.  STEN magazines are neither inexpensive nor abundant, surplus stocks having dried up.  Masterpiece Arms primarily focuses on high-end precision rifles and chassis systems, but they still make MAC-style pistols in 9mm and 5.7x28mm under their “Defender” line.

MPA 30 (Masterpiece Arms 9mm Defender) Pistol Review

The variant I purchased is the MPA-30SST.  It’s a product-improved variant of the old Cobray M11/9.  It has a straight grip and utilizes STEN-type magazines.  The charging handle has been moved from the top to the left side.  A length of Picatinny rail is mounted to the top of the upper receiver and another, shorter bit is mounted to the underside of the lower in front of the trigger guard.  It comes with a “safety extension”, a sort of faux-suppressor machined from solid aluminum.  This can be removed, revealing a muzzle threaded at 1/2×28.

Masterpiece Arms MPA-30 SST "Defender" in 9x19mm

Masterpiece Arms MPA-30 SST “Defender” in 9x19mm.


MPA30 threaded muzzle.

The safety extension can be removed, revealing a 1/2 x 28 threaded muzzle.

The charging handle is on the left side of the upper receiver, and doesn’t reciprocate upon firing.  It is similar in construction to that of the FAL rifle.

The charging handle is reminiscent of the FN FAL rifle.

The charging handle is reminiscent of the FN FAL rifle.

While the pistol is descended from the M11/9, and through it the original MAC-10, I believe it to the finest iteration of the pistol ever produced.  Masterpiece Arms’ quality control is excellent, and the weapon has been modernized and improved in several ways.  The most noticeable difference between this gun and an original is the improvement in the grip; originals had a stamped steel grip frame that was blocky and uncomfortable.  The MPA-30 has a lower receiver machined from aluminum.  This results in a significant weight reduction as well as improved ergonomics.  The magazine release is a large paddle at the heel of the grip.  Removing magazines is easy and can be done without breaking the firing grip.

Masterpiece Arms Defender grip frame.

The Masterpiece Arms Defender grip frame.

More About Magazines

A note about magazines: as stated above, original STEN magazines are neither abundant nor inexpensive these days.  For years, TAPCO manufactured plastic magazines that would work with either the STEN or the Masterpiece Arms pistol, as well as a magazine loader.  They seem to have discontinued production of these, though they can still be found on sites like Gun Broker and GunsAmerica.  Masterpiece Arms still manufactures magazines and a magazine loader for the MPA 30 Defender Pistol, and they can be purchased from their website.  I was able to stock up on magazines by hunting around online.

MPA 30 magazines

MPA 30 magazine.

(If using a proprietary magazine is a deal-breaker for you, Masterpiece Arms also sells a variant of this pistol that uses Glock 17 magazines.)

TAPCO STEN magazine loader: a must-have.

TAPCO STEN magazine loader: a must-have.

The TAPCO brand magazines I purchased are robust but proved extremely difficult to load by hand.  I purchased a magazine loader tool and would recommend it if you’re interested in this kind of pistol.  Without it, getting more than twenty rounds in the magazine was almost impossible.  With it, loading them to a full thirty rounds was no trouble.

TAPCO mag loader in action.

The magazine loader in action.


Ammo Matters

In my first outing with the MPA 30 Defender Pistol, I experienced numerous malfunctions with Remington UMC (green and white box) FMJ ammunition.  For my next time out, I purchased Winchester white box 9x19mm NATO spec ammunition and the malfunctions ceased.  NATO-spec 9mm runs a little hotter than SAAMI-spec, and sometimes a blowback weapon (especially one originally designed as a machine gun) needs a little more oomph to reliably cycle.

Winchester 9x19 NATO-spec ammunition proved reliable in the pistol.

How Does it Shoot?

In my honest and subjective opinion, it shoots about how I expected.  I was pleased to discover that it didn’t have the unpleasant trigger slap that semiauto MAC pistols have been known for.  You can feel the bolt cycling in the trigger, but it’s not a distraction. Also, the trigger comes with a rubber boot over it to cushion it further.

MPA-30 fire control group


The Defender is a large pistol, large enough that it doesn’t handle or point like a conventional handgun.  Despite weighing almost four pounds the recoil is noticeable; being blowback operated and originally intended to be full auto, it utilizes a big, heavy bolt, and all of that mass flipping back and forth can be felt by the shooter.

MPA 30 Defender Pistol bolt

The bolt is a substantial piece of steel.


The gun’s metallic sights are also improved over the originals, at least in terms of firing the weapon like a pistol (vs. having a shoulder stock).  The rear sight is a V-notch and the front sight is a steel post, protected by stout wings.  Both are painted white for better visibility, and the sights proved serviceable, if not outstanding.  Instead of relying on them, however, I decided to install a small red dot sight.  The Sig Sauer Romeo-5 is small, lightweight, of decent quality, and has proved very durable in tests performed by various YouTubers.  It can also be purchased for about $120, so it seemed like the perfect match for the MPA-30.  I was not disappointed.

The rear sight, adjustable for windage.

The rear sight, adjustable for windage.


The front sight, adjustable for elevation.

The front sight, adjustable for elevation.


The MPA-30 is a hefty pistol and one that’s more awkward to hold than a conventional semiautomatic handgun.  It could definitely benefit from a single-point sling or an arm brace.  If you wish to add either of these, there are threaded holes in the rear of the receiver that facilitates attaching them.  Masterpiece Arms sells both a sling swivel attachment and a buffer tube adapter, which will allow you to install an arm brace designed for an AR-15-style pistol.  Both of these items can be purchased from the MPA online store.

MPA 30: the rear of the lower receiver has attachment points for various accessories.

The rear of the lower receiver has attachment points for various accessories.

MPA 30 Defender Pistol Design

Owing to its ancestry, the MPA-30 is, mechanically, a very simple design.  Removal of the front push pins (inner and outer) allows the upper receiver to slide off.  The bolt and buffer come out as one piece.  The barrel is fixed into the upper receiver.  The gun is easy to field strip and only has a few parts.

top down view, MPA30


Masterpiece Arms Defender pistol



Perhaps the most important question one could ask a firearms reviewer is, “would you recommend this gun?”  In the case of the Masterpiece Arms MPA-30, my answer is yes, but with some caveats.  If you want an M11-style pistol, the MPA line is the pinnacle of the design’s development. Not since Gordon Ingram first dreamed up the MAC-10 in 1964 has such a high-quality example of the gun been produced.


However, the legal requirements to sell this gun as a pistol place some limitations on the original design.  Lacking the select-fire trigger group, it cannot be used as originally intended.  Not having a shoulder stock somewhat inhibits good shooting, though this can probably be mitigated by using a taut single-point sling or an arm brace.  As is, it doesn’t really do anything a conventional 9mm pistol can’t, and there are certain roles it isn’t suited for (carrying this weapon concealed is not practical, for instance).

This is not to say that it couldn’t be used to defend your home. Or that it couldn’t find some utility as, perhaps, a truck gun.  I just don’t know that it would necessarily be better at these roles than other firearms.  Also, if I had it to do again, I would perhaps consider the MPA-30-DMG model, the one which utilizes Glock magazines.  Glock magazines are ubiquitous these days and are readily available at gun stores and online.

That all said, I love mine and don’t regret purchasing it.  It’s cool-looking, it’s different, and it’s fun to shoot.  Masterpiece Arms makes a good product.

Learn more about the MPA Defender series pistols online:


MPA30 Defender pistol from Masterpiece Arms

The Masterpiece Arms 9mm Defender. Not at all a purchase the author regrets.


Movies from the 80s made many guns all but iconic.

Movies from the 80s made many guns all but iconic.


Masterpiece Arms 9mm Defender and related imagery

Customer photos and pictures from various Masterpiece Arms social media platforms. 

MPA30 customer photo via MPA social media


MPA30 customer photo via MPA social media


MPA30 customer photo via MPA social media


MPA30 customer photo via MPA social media


MPA 30 Defender Pistol customer photo via MPA social media


MPA 30 Defender Pistol customer photo via MPA social media


MPA 30 Defender Pistol customer photo via MPA social media


MPA 30 Defender Pistol customer photo via MPA social media


MPA 30 Defender Pistol customer photo via MPA social media


MPA 30 Defender Pistol customer photo via MPA social media

If you liked this article, check out all of the other great articles written by Mike Kupari on The Mag Life.

Mike Kupari

Kupari is a wrong-handed Air Force EOD combat veteran of Afghanistan turned novelist. Now a civilian, he has spent a disturbing amount of time rendering safe a number of things that would otherwise blow things up. Much of the time he was doing that in a place where favorite local pastimes include such activities as shooting, blowing up or even eating Westerners.

Mike says,

Buy my books. If you think this article is stupid and that I’m stupid, don’t hold it against my books. My books have nothing to do with anything in my article that might make you mad, so you should still buy them.

  • ahamiltonfederalist

    ugly little beast but i like it – just because

  • SemperFlyBoy

    Looks like the result of an ugly high speed collision between a Borchardt C-93 and a grease gun.

  • Mark Baer

    I own one and it’s a terrible pistol. Among other things it will not shoot hollow point rounds (and I tried a lot including the ones mentioned below). MPA Comment from email I sent them
    “Thank you for the follow up.Our MPA Defenders are designed for FMJ ammunition, though end users have noted positive results with the more rounded shaped projectile hollow points like Hydrashok or the Powrball made by Corbon.”

  • jay

    So what are the prices? Is it a select fire firearm? I’ve heard nothing but, well that these firearms are meh. So, why own one if you aren’t going to have a select fire weapon, then sbr it, so you can play?

  • Dave Brown

    No reason not to play with these or even the old Cobray’s, but with them plan on a few parts as many prior owners filed things down a little to get them to bump fire, or climb the pole as they said in the day. I really don’t enjoy bump fire so I fixed both Cobrays so they worked as a semi auto. Yes I have used folding stock type things, and arm braces which of course should never be shoulder. I shoot a lot of reloads, and I mean a lot. With a little work the MPA full size 9mm will hit good at 50 yards all day long. I still own a few in 9 and 45, and I plan to play with them a lot more once I get settled in from a major move. Home Defense or Hi Cap Truck or Bike gun would seem just fine. Are there better options yes in a way, but for an interesting firearm that few will own these are Tops in my book. I never really got around to trying HP ammo in these. I also really enjoy my Kel-Tec 2000 in 9 and of course 40, but again I shoot them a lot with reloads solid tips. Now I have the MPA and Kel-Tec shooting good at 50 yards and the Kel at up to 100 yards I will start messing with HP. For close in work just get a few 357mags and have at it……………… Dave PS: You can find good deals on MPA firearms

  • Judge Mental

    You know that feeling when you hit your thumb with a hammer? If you like that, you will LOVE how your index finger feels after 5 or 10 rounds. Not 5 or 10 mags. Individual rounds. The most miserable gun to shoot I’ve ever owned (for a little over 24 hours, I hope the buyer doesn’t hunt me down) I trust the maker and others will deem me a wuss. Maybe so but hurting yourself repeatedly just seems dumb.