By Nick Jacobellis

One of the more significant advancements that has been made in the firearms industry, has

involved the installation of side folding, under-folding, and retractable/telescoping stocks on a variety

of rifles, submachine guns, as well as on certain shotguns. In recent years, a device known as a

Stabilizing Brace has also been made available, for use on certain firearms that are legally designated

as a pistol. While we may take this for granted today, it is important to remember, that for a very long

time, rifles and all “shoulder fired capable” weapons were fitted with a wooden stock. This included a

number of pistol caliber submachine guns.

            The primary benefit of using a folding, or a retractable/telescoping stock, involves the ability to

transport and operate a more compact firearm. Certain firearms are also a bit lighter to transport, carry

and utilize in confined spaces, when they are equipped with a folding or collapsible/retractable stock

that is manufactured in lightweight polymer. In recent years, the use of a polymer Stabilizing Brace has

made it possible for legally armed end users to operate firearms that are legally designated as a “pistol.”

Using a lightweight Stabilizing Brace, like the type made by SB Tactical, makes it possible to more

accurately engage targets from a standing unsupported position, especially when engaging targets at

longer distances.

                                                               IN THE BEGINNING

            The first rifle caliber firearm that was fitted with a very well made side folding metal (wire)

stock, was issued to U.S. Army paratroopers during World War II. The Inland Model M1A1 .30 Caliber

Carbine was ideally suited for use by airborne troops, who were dropped by parachute or delivered into

a combat zone in a glider. The Inland Manufacturing Division of General Motors manufactured

140,000 M1A1 Model .30 Caliber Carbines during World War II.

            As someone who trained with a government issued .30 Caliber M1 Carbine, while attending

the Federal Law Enforcement Training Center (FLETC) in Brunswick, Georgia, who also owns a

WWII era M1A1 Carbine, I can attest to the pros and cons of the rifle that is commonly called the

“Paratrooper Model.” The main reason why the Inland Model M1A1 was ideally suited for use by U.S.

Airborne troops, was the compact nature of the design, when the metal “wire” stock was in the folded

position. As an added benefit, the Inland Model M1A1 Carbine could also be operated and fired with

the side folding metal wire stock in the folded position. This was such a popular design, that a number

of manufacturers produced post WWII era M1 Carbines, that were fitted with a side folding metal wire

stock. Perhaps the best specimen of a post World War II M1 Carbine, that is equipped with a side

folding stock, is manufactured by the Auto Ordnance Corporation.

                                                                  THE REISING

            The .45 ACP Caliber M50, M55 and the M60 Reising Submachine Gun was briefly issued to

certain U.S. Marines during the early days of WWII. The M55 Reising was fitted with a side folding

stock. Despite the lower cost of production and certain innovative features and lighter weight

construction, the poor performance of the Reising in combat caused this firearm to be withdrawn from

field use.

                                                            THE M3 GREASE GUN         

            One of the most interesting pistol caliber submachine guns used by Allied Forces during World

War II was the .45 ACP caliber U.S. made M3 Grease Gun. The M3 Grease Gun was a very unique

design, that was required to be manufactured using all stamped and welded metal parts that required

very little finishing. The M3 was designed to be a less expensive alternative to the Thompson

submachine gun during WWII. The M3 was also designed to operate with a slower rate of fire and

utilized a metal 30 round magazine.    

            Even though a telescoping metal wire stock was incorporated in the design, the M3 was often

fired with the stock collapsed. This was made possible by the operator holding the pistol grip with his

strong hand, while gripping the area around the magazine-well with his weak hand. 

            The M3 utilized a throw lever style cocking handle to load the chamber and clear stoppages.

The M3A1 Model of the famous Grease Gun replaced the throw lever charging handle with two

indentations in the bolt assembly, that were used by the operator to retract the bolt. 

            While the M3 was primarily chambered for use by U.S. and Allied military personnel in .45

ACP caliber, a 9mm M3 was made for use by U.S. Office of Strategic Services (OSS) supported

(Allied) resistance units operating in German occupied countries. The 9mm M3 variants were

specifically chambered in the 9mm caliber, so resistance fighters could utilize captured German 9mm

ammunition. Over 600,000 M3 and over 40,000 M3A1s were manufactured at a cost of $15 dollars

each. M3s and M3A1 were used in combat from 1944 to the end of WWII and were later used in the

Korean War, with some Grease Guns being used in the Vietnam War, as well by tank screws during

Operation Desert Storm. As someone who has field tested various submachine guns, the M3 is a

personal favorite.

                                                            THE GERMAN MP40

            Even though the Germans used other 9mm sub guns, including captured Allied weapons, the

MP40 or Maschinenpistole 40, was the most widely used 9mm submachine gun in the German

Armed Forces during WWII. The MP40 was another blowback operated firearm that fired from an

open bolt. The MP40 was able to be transported/carried and fired with the well made metal stock

folded. The stock on the MP40 was considered an “under-folder,” because the stock could kept folded

under the frame of the MP40, which made this submachine gun more compact. The MP40 could also

be fired with the metal stock extended and locked into the open position.

            The MP40 has been incorrectly referred to as The Schmeisser. This occurred when Allied troops

recovered MP40s on the battlefield and the only name that was found on this weapon, that was located

on the magazines, was Schmeisser. While Mr. Yugo Schmeisser was a German arms inventor who

designed the magazines that were used in the MP40, the weapon that Schmeisser was actually famous

for inventing was the MP18. Much like the U.S. made M3 & M3A1 Grease Gun, the MP40 was also

manufactured using a number of metal stamped parts.

                                                                    THE VIETNAM ERA

            During the Vietnam War, the select fire M16A1 with a fixed polymer stock and a 20 inch barrel

chambered in .223/5.56 caliber was the full size general issue main battle rifle. The original AR15 and

the Colt M16A1 initially utilized a 20 round lightweight metal box magazine. A higher capacity 30

round metal magazine eventually became standard issue for the M16.

            To make the M16 a bit more compact, a shorter version known as the Colt CAR15 XM177 was

manufactured. The Colt CAR15 with fitted with a retractable polymer/plastic stock and a shorter 10

inch barrel. The CAR15 E2 version had an 11.5 inch barrel. During the Global War on Terrorism the

M4 variant with a 14.5 inch barrel became standard issue and eventually replaced the M16s with a

heavy 20 inch barrel as the primary U.S. (main) battle rifle. Optics and other accessories also became

standard issue and were widely used on military rifles and even on the patrol carbines that are currently

used by law enforcement officers. The Colt CAR 15 that I was issued during my career in the U.S.

Customs Service had a 16 inch barrel. This rifle was ideally suited for use in and out of interdiction

aircraft, while operating on vessels and while operating in more remote locations along a land border. 

            The most popular 9mm submachine gun used by certain U.S. Special Forces (Studies &

Observation Group aka SOG) personnel during the Vietnam War was the 9mm Carl Gustaf m/45B

known as The Swedish K. The Swedish K developed a sterling reputation for reliability while being

utilized in a harsh jungle environment. The 36 round box magazine and the relatively low rate of fire of

600 rounds a minute contributed to the ease in which the Swedish K could be effectively and accurately

wielded in battle. The Swedish K was also fitted with a side folding metal stock, that made this sub gun

more compact when the stock was folded.  

            When the Swedish government refused to sell additional m/45s to the U.S., Smith & Wesson

was approached to make a 9mm submachine gun. Even though the S&W M76 was not an exact copy of

the Swedish K, the Smith & Wesson sub gun shared the general appearance and method of operation of

the m/45. The adoption of the S&W M76 was short lived as different variants of the short barreled

carbines known as the CAR15 came into more widespread usage.     

                                                                THE AK VARIANTS

            The Cold War and the Vietnam War also saw the widespread use of fully automatic Communist

Block (COMBLOC) AK47s chambered in 7.62×39 caliber, that were fitted with a traditional wooden

stock, or an under-folding metal stock. The metal under-folder that is used in AK47s is similar in

design, to the metal under-folder that was used on the German MP40. 

            Several years after the adoption of the M16 and the Colt CAR15 by the U.S., the Russians

developed the 5.45×39 caliber that was used in the AK variant known as the AK74. While AK47s were

still in widespread circulation, the AK74 became the main battle rifle that the Russians carried during

their invasion and occupation of Afghanistan. The AK74 is also the main battle rifle that is being used

by both Russian and Ukrainian troops in the current conflict in Ukraine.

            Much like the .223/5.56 caliber U.S. made AR15/M16/CAR15/M4, the Soviet made AK74 is 

chambered in a “lighter” 5.45×39 caliber. The U.S. designed 7.62×51 (.308) NATO caliber ammunition

and the Soviet 7.62×39 caliber ammunition are both heavier .30 caliber bullets, that weigh more than

the .223/5.56 NATO and the 5.45×39 calibers. The benefit of utilizing a battle rifle chambered in the

U.S. made .223/5.56 NATO caliber and or the Soviet designed 5.45×39 caliber, is the ability of combat

troops to more comfortably carry a larger combat load of ammunition. Rifles chambered in .223/5.56

NATO and 5.45×39 also produce less felt recoil than rifles chambered in .30 caliber ammunition

(7.62×51/.308 and 7.62×39.) Unlike the AK47 that was manufactured with wooden stocks and under-

folding metal stocks, the bulk of the AK74 rifles are fitted with a standard wooden or a polymer stock.

That said, the wooden “furniture” or stock on AK74s is not considered to be all that heavy.

            As someone who purchased fully automatic AK47s from an unlicensed arms dealer, while

working undercover along the Mexican Border, who has also field tested various semi automatic

AK47s, I personally find the models with the stamped receivers and the fixed stocks to be the lightest

The Chinese wooden AK47 stocks are also a tad shorter in length and are personally preferred. The

AKs with milled receivers, like those made by Zastava (in former Yugoslavia), that are equipped with

an under-folding metal stock are the heaviest AK variants. That said, regardless of the type of receiver

(stamped or milled), AKs that are fitted with an under-folding metal stock are more compact.

            I have also field tested and trained with semi automatic Bulgarian AK74s, one with wooden

“furniture” and one with a side folding metal (wire) stock. Just like every other AK variants, both of

these rifles proved to be flawlessly reliable and easy to carry in the field. As stated above, the two main

differences between the AK47 and the AK74 involve recoil and the weight of the ammunition. Utilizing

polymer magazines, as opposed to all steel AK magazines, can also aid in reducing the weight of your

combat load. One comment on magazines involves the rather steep cost of original AK74 magazines.

The good news is, that the Magpul AK74 magazines that I purchased are as reliable as the original

Bulgarian AK74 magazines that I purchased, when these magazines were reasonably priced.    

            The AKS-74U Krinkov or Krink is a shortened version of the AK74 chambered in 5.45×39

caliber, that was manufactured with a very well made side folding triangular shaped metal stock. The

The Krinkov has an 8.1 inch long barrel, weighs under 5 pounds, is just under 30 inches with the side

folding metal stock extended and is just under 20 inches long with the stock in the folded position.

While field testing an AKS-74, I found the sights to be easier to acquire than the sights that are used on

full size AK47 and AK74 rifles. This doesn’t meant that I am unable to effectively use traditional AK47

style sights. It means that my eyes find the Krink style sights to be more “user friendly” and easier to

acquire.  The Krinkov is a compact rifle caliber firearm that is well suited to be used by personnel who

operate in tight quarters.

            A company called Zastava manufactures some of the most robust and rugged AK variants in

various military calibers. One of my personal favorites is the Zastava ZPAP85; a firearm that is

designated as a pistol, that can once again be legally sold and possessed with a SB Tactical Stabilizing

Brace. The ZPAP95 is chambered in .223/5.56 NATO caliber and is basically a semi automatic version

of the original Krinkov, that is fitted with a 10 inch chrome lined barrel barrel, a stamped steel receiver,

a hinged top cover, a Krink style rear sight and a dual aperture front sight. Zastava also makes a rifle

model in 5.56 with a 16.5 inch barrel, that is fitted with Krink style sights and side folding or a

collapsible stock. ZPAP 85 models are also available with a FDE (Flat Dark Earth) Finish.

            The Zastava ZPAP 92 is a 7.62×39 caliber variant that is available as a Krink style pistol with a

10 inch barrel, or as a rifle with a 16.5 inch barrel and a FDE/Flat Dark Earth Finish. Zastava also

manufactures a ZPAP model with an Artic White Camouflage Cerakote Finish.

            The newest edition to the Zastava lineup is the PAP M77, a rifle chambered in 7.62×51 (.308)

caliber, that has a 19.7 inch Cold Hammer Forged Threaded Barrel, utilizes 20 round magazines, is

fitted with a Promag adjustable/collapsible polymer stock and a TD “pistol” grip. The unloaded weight

of the Zastava M77 is 8.6 pounds.

            The Zastava M90 is a 5.56 NATO caliber rifle with an 18.25 inch barrel that utilizes 30 round

polymer magazines and is available with different stock options to include a wooden stock set or a

Magpul manufactured Zhukov Folding Stock, with an MOE Grip and a Hogue Handguard, that weighs

8.5 pounds unloaded.

            When you compare the M90 in 5.56 NAO to the M77 in 7.62×51 or .308 caliber you can see

that both rifles are very similar in barrel length and weight. Much like the comparison between the

AK47 and the AK74, the difference between the M77 and the M90 involves the weight of the

ammunition, especially since the M77 utilizes all steel 20 round magazines. Once again, the weight of

the combat load is a consideration. However, some will argue and rightfully so, that .30 caliber 7.62×39

and 7.62×51 caliber rifles provide improved stopping power, especially at longer ranges.

            The wild card in this discussion involves the type of ammunition used. Modern commercial

5.45×39 caliber ammunition for AK74 variants does not perform like the original Soviet AK74 7N6

steel core bullet configuration, that is currently banned from being imported in the United States.

Likewise, 77 grain 5.56 caliber ammunition is a more capable performer than standard 55

grain .223/5.56 ammunition. This means, that when used with the right ammunition, the U.S.

AR15/M16/M4 rifles and the AK74 can be more effective than the same rifles loaded with more

standard commercial ammunition.                             


            As mentioned above, the first rifle that I carried in harms way, that utilized a lightweight

retractable/collapsible plastic stock, was a Colt CAR15. This rifle was issued to me when I served in

the U.S. Customs Service and I flew as a crew member on drug interdiction aircraft in the Caribbean.

I also carried my issued Colt CAR15 when I conducted smuggling investigations, while operating on

land and when working on an undercover vessel off the coast of Colombia.


            The 9mm Heckler & Koch MP5 was the general issue submachine gun that was utilized by the

U.S. Customs Service and a host of other law enforcement agencies and special operations military

units. Even though the HK MP5 was the primary 9mm submachine gun that was available for issue to

U.S. Customs Agents, I ended up utilizing a 9mm Walther MPK instead. I was issued a 9mm MPK

when I was serving as a Special Agent assigned to the Miami Air Smuggling Investigations Group 7,

that was co located with the Miami Air Branch at Homestead Air Force Base. The 9mm MPK was a

true Cold War era sub gun, that came into service before the emergence of the more “modern” HK

MP5A3, that was widely used during the Drug War, as well as during post 9/11/01 Global War on


            Even though the older stamped steel 9mm Walther MPK with the 6.7 inch barrel was a tad

heavier at 6 pounds 4 ounces unloaded, compared to the 9mm HK MP5A3, that weighed 5 pounds 10

ounces unloaded, I found the Walther variant to be just as reliable as the HK MP5A3. One difference

involved the appearance of both firearms, with the Walther MPK looking nothing like the type of sub

gun, that was in widespread distribution in law enforcement agencies and special operations military

units. The Walther MPK was also fitted with an extremely rugged metal wire side folding stock

compared to the retractable/telescopic stock that was used on the MP5A3. One of the reasons why I

personally preferred the Walther MPK, was because I could use the extremely well made metal wire

folding stock to break vehicle or motel glass windows if necessary.  When you work undercover, or you

provide backup to other undercover personnel, it gives you peace of mind to know, that the submachine

gun that you carry can be used to easily smash your way into motel rooms, or into locked vehicles, to

take a major violator into custody, or rescue an undercover agent who is being held hostage. 

            I also felt that the 9mm Walther MPK was ideally suited for use by an undercover agent,

because the MPK was issued to me in a “nondescript” heavy green cotton canvass zippered case that

contained three steel 32 round metal magazines. This package was so compact, I was able to travel with

my MPK. I also carried my issued Walther MPK in my undercover vehicle.

            The 9mm Heckler & Koch MP5K is considerably more compact than the MP5A3 or the

Walther MPK. With a barrel of 4.5 inches and an overall weight (when empty) of 4.5 pounds with an

unloaded magazine, the MPK utilized either a 15 or a 30 round magazine. The MP5K is capable of

full auto fire, burst fire or single action fire. The HK MP5K was and still is ideally suited for those

applications that requires an operator to possess a more compact submachine gun. The HK MP5K can

be carried with or without the side folding stock attached.

            As someone who trained with and field tested a standard MP5A3 with a telescope stock, as well

as the more compact 9mm MP5K with a side folding stock, I agree that while both variants can be

utilized in a traditional submachine gun role, the MP5K is the better of the two variants to be carried,

when it is necessary to possess the most compact and concealable submachine gun possible.

                                                      ITALIAN COLD WAR CLASSICS

            The Italian BM59 was a modified M1 Garand rifle, that was chambered in 7.62×51 (.308) and

fitted with a 20 round metal box magazine. The American made M14 bears a striking resemblance to

the modified American made M1 Garand rifles that were converted into BM59s. The MKIII version of

the BM59 was equipped with a pistol grip and a metal folding stock and was designed for use by Italian

Mountain and Airborne Troops. The Italian BM59 represents one of the .30 caliber Allied/NATO rifles

that were made into a more compact model when equipped with a folding stock.

            The trend of transitioning to 7.62×51 (.308) caliber main battle rifles continued during the Cold

War era of the 20th Century. It was during this period of time that the German arms manufacturer

Heckler Koch produced the venerable G3/HK92. When NATO transitioned to 5.56 caliber battle rifles,

Heckler & Koch developed the HK93, a full size higher capacity magazine rifle chambered in 5.56

NATO caliber, that was available with a retractable/collapsible stock. The HK93 was another rifle that

was available to U.S. Customs Agents who served in South Florida during The Miami Vice Era of the

Drug War.

            The Italian made Beretta Model 12 is another very well respected but often less known 9mm

submachine gun, that saw widespread service during the Cold War. The Beretta Model 12 is another

premium brand 9mm submachine gun, that had a sterling reputation for reliability and was made under

license in Brazil and Indonesia. The side folding metal “wire” stock, that was fitted on the Model 12,

provided the end user with the ability to “shoulder” this sub gun, when it was necessary to deliver more

precise “aimed” fire. The Beretta Model 12 utilized 20, 32 and 40 round metal (stick) magazines. 

                                                                 GWOT RIFLES

            The EBR or Enhanced Battle Rifle was developed during The Global War on Terrorism. Simply

put, the Mk14 EBR or Enhanced Battle Rifle was an M14 that had its wooden stock replaced with a

chassis system. The EBR chassis system contained a telescoping retractable (dual wire) metal stock and

rails for the mounting of an optic, a bi pod and a laser. EBRs were also used as Designated Marksman

Rifles. Two variants of the EBR were produced, one with a 22 inch barrel and one with an 18 inch

barrel. The first U.S. military personnel to be issued an EBR were Navy SEALs. EBRs were also used

by U.S. Army Designated Marksmen. The EBR that I evaluated was issued to U.S. Customs & Border

Protection Black Hawk helicopter crews.

                                                               THE FN SCAR 17

            The FN SCAR Mk17, also known as the SCAR Heavy, or Special Operations Combat Assault

Rifle. While the SCAR Heavy is chambered in 7.62×51 (.308) and utilizes as 20 round magazine, the

FN SCAR Light is chambered in 5.56 NATO and utilizes AR15/M16/M4 magazines. Both SCAR rifles

are fitted with a side folding polymer stock. The Mk SCAR 17 is available with a 13, 16 and a 20 inch

barrel. I evaluated two FN SCAR Heavy Mk17s, one a commercial model with a 16 inch barrel that

was equipped with a Trijicon ACOG and one that was issued to U.S. Customs & Border Protection

Black Hawk helicopter crews. The DHS/U.S. Customs SCAR Heavy was equipped with an ELCAN

optic and laser.                                                           

                                                        THE BERETTA ARX100/160

            The Beretta AR100 is the semi automatic version of the Beretta AR160. While the bulk of the

AR100s and 160s were chambered in 5.56 NATO, this rifle was reportedly also available in other

calibers. The version I field tested was a semi automatic ARX100 chambered in 5.56 NATO. When

chambered in 5.56 NATO, the AR100/160 is a piston driven battle rifle that utilizes AR15/M4

magazines. The ARX100 is an amazing performer that weighs under 7 pounds unloaded. This is one

rifle that I regret not buying. The Beretta (M4 style) NARP (New Assault Rifle Platform) is replacing

the select fire Beretta ARX160.     

                                                SHOTGUNS GET MORE COMPACT        

            The discontinued “Jungle Gun” version of the semi automatic Mossberg 9200A1 12 gauge

shotgun was an interesting design, that had an 18.5 inch barrel and was fitted with a very well made

and rugged side folding Choate stock. The 9200A1 also had a corrosion resistant Parkerized Finish, a

thicker walled barrel, synthetic “furniture” and all metal parts construction. One drawback of the

9200A1 was it’s limited 4 round tubular magazine capacity. That said, the 9200A1 was one of the few

“combat” shotguns of its day that was available with a side folding stock. Being equipped with a side

folding stock made it easier to transport and deploy a 9200A1 when operating in confined quarters.

            Remington Arms Company also manufactured one of their 870 Model 12 gauge pump

action shotguns with a 16 inch barrel, that was equipped with an under-folding metal stock and a pistol

grip. Even though this under-folding metal stock was on the heavy side, it enabled the end user to carry

and transport a more compact shotgun. This is a perfect example of the expression, that life is all about


                                                           A TOP GUN BULLPUP

            The Springfield Armory Hellion is a 5.56 NATO caliber bullpup rifle that is fitted with a

retractable polymer stock. In fact, the semi automatic Hellion and the select fire Croation military

variant called the VS2, are the only bullpup rifles that are equipped with a retractable/collapsible stock.

(I am in the process of evaluating the extremely well made Springfield Armory Hellion for ARGunners.

I expect to publish the results of this T&E in a few weeks.) 

            SB Tactical is a company that embodies the meaning of the famous saying, “Necessity is the

mother of invention.”  Once ATF loosened its official position on how Stabilizing Braces could be

used, new products were developed, that could be installed on firearms that were designated as a pistol

under federal law. SB Tactical is a leading producer of Stabilizing Braces in the U.S. and currently

manufactures a variety of models for every firearm designated as a “pistol.” Installing a SB Tactical

Brace on any firearm that is legally designated as a pistol, makes it possible to fire such a firearm from

your shoulder. 

About the author: Nick Jacobellis is a Medically Retired U.S. Customs Service Senior Special Agent and a former NY police officer who was physically disabled in the line of duty while working undercover as a federal agent. To date the author has published 240 magazine articles in various law enforcement, firearms, survival and military history magazines, as well as 14 action packed non-fiction, historical military and police procedural fiction books of the following titles: Tactical Survival 101, Controlled Delivery Book One and Book Two, The Front Line Fugitives Books I, II, III, and IV, Buck Banderas U.S. Marshal Books One, Two and Three, A Special Kind of Hero, The K9 Academy-The Second Edition and Guns South. A number of 5 Star reviews have been posted on (US) and (UK) as well as on The author’s 14th book is a Christmas story titled: Santa’s Christmas Tree Convoy. The author was born and raised in Flatbush section of Brooklyn New York and has an BS Degree in Police Science from John Jay College of Criminal Justice.  

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