Star Firearms : Sub-machine Guns

Star Firearms — Sub-machine guns

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Despite being known best in the commercial market for handguns, Star's primary business has been in many ways their military submachine guns. The fall of the SMG in the 1980s to the 5.56 mm carbine may even have been a contributing cause of their eventual demise.

From just before the Civil War, until the 1990s, one Star SMG model has replaced another in Spanish army service, as well numerous export countries. For more, read up on stocked- and machine-pistols or find your stocked SMG in the progression of Spanish service weapons:

Si35, RU35 & TN35Z-45Z-62 & Z-63 Z-70 & Z-70/BZ-75 & Z-84

Machine Pistols & Pistol Carbines

A model MP semi-automatic carbine

A number of classic-era Star pistols were also made as "machine-pistols" with a selective fire mechanism and detachable buttstock. They all, as far as I know, use the same mechanism, and as they are a unique subset are going to be discussed as a whole here. All of these guns have a "D" suffix (MD, PD). There is a similar series of semi-auto guns also with a detachable butt with a "B" suffix which will be discussed as well.

Only two series were produced in B and D variants. The first seems to make sense, as it is the larger framed model M. The extra weight and strength would seem to justify its existence as a pistol at all, when it otherwise seems repitious of the A series. The other is, however, the .45 caliber P series. While not weak in full-sized pistol format, this cannot be said to be a good thing from recoil or wear when fired in automatic.

It appears as though there was only a small production run of these weapons, or perhaps several small runs over time. Reportedly, fewer than 8,000 of all automatic (D) variants were sold between 1930 and 1952. I have no idea how many semi-auto stocked versions (B) were produced. Neither of these seem to carry thru other changes to the series such as safety or other improvements, and there are no Super variants. There are a number of factory presentation models of these guns available.

Manuals & Disassembly Instructions

I do not have manuals for every pistol shown on this site. However, in many cases there is a related manual. Partly to make the series relationships clearer, and partly to assist with speed and accuracy of updating, all manuals can be found in one place, the manuals page. All manuals available are provided as downloadable PDFs, or you may purchase a printed copy of the entire set of handgun manuals.

Most stripping and operating instructions are identical to the semi-automatic base gun so refer to the best manual for that pistol. It is possible no SMG manuals were made, as a small number of machine-pistol owners got pistol manuals with their guns.

The fire selector and automatic safety mechanisms


The fire selector is unrelated to attachment of the stock, so can be engaged when it shouldn't be, as a handgun alone. The fire selector is a vertically-sliding switch on the right side of the slide, amongst the cocking serrations. It is also unrelated to the safety lever, so the safety may be engaged and disengaged as is usual for the handgun.

Patent number 116,773, granted 11 February 1930 covers Star's method of automatic operation. Under normal, semi-automatic fire, Star pistols are prevented from continuing to fire by the disconnector. This is a sliding bar (or, in later iterations and the Firestar series, a simple extension to the transfer bar itself) that pushes the transfer bar under the sear as soon as the slide moves out of battery; this same process also acts as an effective in-battery safety.

The fire selector and automatic safety mechanisms

When the selector is slid down to automatic fire, the switch performs two roles. First, it fills the slot which allows the disconnector to function. Second, it pushes forward on the auto trip lever as the slide returns to battery. This lever uses the uppermost stock panel bushing as an axis pin, so the bottom portion of the lever rotates to the rear. A cam cut out of the lower portion of the auto trip lever engages with a pin protruding from the side of the trigger transfer bar.

Not having one to examine in person, the details of the cam action elude me. Clearly, it causes the transfer bar to disconnect from the sear momentarily, then causes it to trip and fire. This delay is necessary to allow the hammer to fall only when the gun is in battery. Aside from safety concerns, a following hammer will not consistently ignite primers. The cam path is clearly cut with a small notch that I think makes sense, but it would seem to cause trigger slap. I expect this would be uncomfortable, but perhaps some slackening of the trigger-finger is a known phenomenon, or there is some part of the trigger to transfer bar connection I cannot see.

As the gun fires, a spring and plunger in the tube visible just above the grip panels pushes the sear trip level rearward, and out of engagement. Only the positive action of the slide running forward, with the fire selector set to automatic, can circumvent the disconnector and cause another shot to be fired.

One reader has reported, without details on how this works, that there is a mechanism that prevents automatic firing at high angles. Presumably this is designed to prevent the gun from climbing out of control under recoil, but it would seem troublesome if enemies appeared in a tower, or on a hillside above you. Therefore I'd take this with a grain of salt until it can be confirmed. Email me if you have a Star machine-pistol and can weigh in either way.

The rate of fire is reportedly somewhere in the 1,200 to 1,400 round per minute range. This is something I have come to expected, as the natural cyclic rate of handguns tends to be very high, and some conversions of other guns run at this rate. However, it appears that in Star machine pistols the rate of fire was controlled by a clever inertial delay mechanism housed under the right grip panel. This reputedly made the D-suffix Star pistols among a very select few machine pistols that could possibly be effectively held on-target in full-auto mode, as well as dramatically reducing the rate of ammunition consumption for a single-stack handgun.

Rate Reducer Variants

A second patent, 133,526 granted in 1934, covered a rate reducer mechanism. While all production pistols I have encountered employ the mechanism described above, one reader has sent photos of an unusual model MD with an extra delay mechanism. This seems to be a different way of achieving the delay in tripping the next round, reducing the rate of fire without changing the other operating characteristics of the gun.

As you can see, it requires a significant mechanism, housed in an oversized right grip panel. It seems superficially similar to the rate reducer on the 35 series SMGs and the years also align with the patent granting date. While finished as nicely as any production piece, I suspect this is a one-off or one of a very limited number of effectvely protoype pieces.

An unusual MD with a rotating delay mechanism


The buttstock is made of wood, and slides into a recess machined into the lower, rear portion of the gripframe. A notch at the bottom of this groove is engaged by a spring-loaded lever to lock the butt into place. The user may retract this lever on the bottom of the stock (this looks like a spare hammer) in order to slide the butt off the gripframe for removal.

The stock and attachment mechanism

The stock, as was typical for others of the era, is hollowed to double as a holster, as shown below. The theory holds that a carbine can be worn in the same size and weight as a conventional service pistol and holster. However, the wooden stock/holster is notably larger, more rigid, slower to use as a holster, and has no particular provision for quickly being detached from the belt.

The stock may function as a sort of holster for the pistol

The stock has metal hardware for attachment to the pistol, plus a metal hinge and latching mechanism for the "holster" component (the pushbutton) and necessary metal hangars for wearing on a belt. The remainder of the stock is machined from a solid wood block. There is no buttplate.


Though Star pistols were produced with a variety of sights, including long-range "tangent" sights, there appears to be no particular inclination to use these on the carbine or machine-pistols. In fact, the only -P or -B variant with long-range sights I have seen is one of those shown in the Ezell book (depicted in black & white on this page). None of the reader-contributed photos have long range sights.

Unlike High Powers, Lugers and Mausers therefore this cannot be used as an identifying feature.


Reportedly, barrels were offered in nine lengths from 75 to 200 mm. Some sources report the 160 mm length as the most common, but almost all I have seen would be more like 110 mm in length, or flush with the front of the slide. I am not aware of any shortened-slide model A, P or M pistols of any sort in this era, so am at a loss to explain the short side of these quoted lengths.


While normal-capacity magazines were employed and function correctly, at least two sizes of extended-capacity magazines were also provided, to add firepower and assure the gun does not run dry in a fraction of a second. There appear to be no special designs to increase capacity such as the Luger "snail" drums; just longer "stick" magazines.

The several sizes of magazines provided

Aside from the length, these vary in having flush floorplates (without the extended nose to facilitate removal) and longer witness-holes to view available ammunition all the way down. Witness holes are not drilled holes, but are long grooves, for magazines of all capacities. Magazines do not appear to be welded up from several normal capacity magazines, but specially made from single-piece blanks. There are welded-on stop plates to prevent over insertion of the extended-capacity magazines.

The floorplates for the extended-capacity magazines appear to be permanently welded units. To allow for stripping, there is a larger punch-out at the top front of the magazine body. This allows the follower and spring to be removed from the top of the magazine instead.

Capacity appears to be 14 and 22 cartridges for the Model M (stamped below the last witness hole). I have no information on extended-capacity Model P magazines.

Siam (Thai) Type 80 Machine-Pistol

In 1938, the government of what we now call Thailand contracted with Greenwood & Batley of the UK for tooling to domestically produce some variant of these machine pistols, to be called the Type 80.

I have never seen one of these pistols, and as far as I know no one else has either. Apparently, the factory was converted to more useful munitions production during the war.