HK's New Tactical .223

by Gary Paul Johnston

It was back in 1981 when I did my first story on the SWAT unit of the Cleveland Police Department. A full-time SWAT unit, Cleveland's 25-officer unit was then, and still is today, one of the best in the country.

I met my friend, Sgt. Bob O'Brien, and Ptlm. Jay Murtaugh at their office in the Cleveland Police Headquarters where they introduced me to officers Larry Jones and Jim Gnew. We began a discussion of SWAT equipment that soon centered on special weapons used by the team.

Several years prior, Cleveland SWAT had purchased a quantity of Heckler & Koch .223 caliber HK53 carbines. While I was examining one of these weapons, one of the officers lamented they'd rather have 9mm HKMP5SD submachine guns instead.

The MP5 was hot stuff back then, and the object of virtually every SWAT cop's affection, including yours truly. A few years later when my agency acquired new SWAT armament, the 9mm MP5 was at the top of my list, a position it would not hold today. Cleveland SWAT soon acquired additional 9mm MP5SD SMGs from H&K, but in my opinion, they left their best tactical shoulder weapon in their arms room.

Back in those days, one of the problems with .223 weapons was that many agencies were issuing G.I. ball ammunition. Whether this was because of perceived reliability or cost depends upon to whom you talk, but it led to other misconceptions.

Remember the Vietnam stories of .223 bullets being deflected by grass? Why the bullets would simply vanish into thin air - they must have, because they never hit their targets? Then in almost the same breath, we heard of the impressive penetration of the full metal jacket .223 and the effectiveness it had against enemy personnel. Could all these things be true at once, and if so, was this bullet unpredictable?

We had a pretty good idea of what 9mm bullets were capable of, and even though it wasn't very impressive, the SMG had a lot of them and they weren't very loud. Yes, the 9mm SMG seemed to be in for the long hall.

However, it didn't take long for some of the more enlightened to see the advantages of the .223 in law enforcement. Using soft nosed bullets at high velocity, these projectiles became frangible, yielding impressive results in ballistic gelatin while at the same time failing to overpenetrate multiple layers of standard building materials.

Today this cartridge has become overwhelmingly popular with law enforcement. Agencies across the U.S. are turning toward the new generation of .223 while sales of the MP5 have dropped. Yet, H&K has an even befter card up its sleeve. This is the new improved HK53 .223 carbine.

A drastically shortened version of the full-length .223 caliber HK33 rifle, the HK53, like all H&K weapons, evolved from the WWII German StG45, a late war prototype using an experimental delayed blowback roller-locking system of operation. With its breech never truly locked, the bolt is held closed by a combination of mechanical advantage coupled with spring tension.

Ingenious in its concept, the roller-locking system works just as good as it sounds. Rather than creating a sharp recoil impulse, the system allows the bolt to unlock with relative smoothness, spreading the recoil over its entire length of travel. However, at the same time, the quick-opening bolt requires the use of a fluted chamber to float the cartridge case on flowing gases during peak pressure to allow extraction to begin.

Since no gas piston or operating rod is used in the HK53's operation, only a non-reciprocating cocking handle is involved, and this rides in a steel tube extended from the receiver. Being totally independent of any part of the barrel or front sight base, this tube leaves the HK53's barrel completely free floating as in all HK rifles.

The HK53 is more than 4 inches shorter than the .223 caliber HK33K from which it evolved. Although Heckler & Koch categorizes the HK53 as a sub-machinegun, it does not fall into this category by American standards even though it's quite short. While the HK53 can provide an excellent substitute for the SMG, it's a carbine firing a rifle cartridge.

Early HK53s came with slim handguards and 3-position non-ambidextrous trigger groups. These guns also had a standard rifle flash suppressor that was not very efficient when used on a short barrel.

Current HK53s come with the Tropical beavertail-type handguards, "Navy" 4-position ambidextrous trigger groups and a redesigned flash suppressor that's very effective. While the standard "Navy" trigger group comes with a 3-shot burst, a 2-shot burst group is also available. The HK 53 can also be ordered in semi-automatic-only, an option I would recommend for any police firearm.

As with all standard HK long guns, the HK53 will accept the standard retractable buttstock or fixed stock. While I much prefer the latter, I insist on improving it by replacing the hard and slippery plastic butt plate with H&K's accessory rubber butt plate. Larger than the plastic version and curved, this butt plate is not only comfortable, it will not slip on the nylon shells worn by entry-level armor officers. In addition to HK's excellent Universal Sling, the HK53 also uses the standard clamp mount made by either HK or A.R.M.S. Equipped with both a Picatinny (Weaver style) rail and NATO STANAG, the A.R.M.S. HK mount will accept virtually any optical sight.


Brand new for the HK 53 is the Modular Weapons System (MWS) from Knight's Mfg. Co., of Vero Beach, Florida. Fitting both the MP5 and the HK53, this unit replaces the forend and provides three Picatinny rails: one along either side and one on the bottom. On these rails can be mounted an endless array of accessories including an optical sight mount, SureFire Tactical Light mount and vertical foregrip.

Even newer than Knight's MWS is their side-mounted scope mount. Since the HK53's cocking handle prevents the use of a top-mounted rail, this scope mount attaches rigidly to the right rail of the MWS and comes up and over the top to mount the excellent Aimpoint red dot sight. A version of this mount with its own Picatinny rail is also being considered to allow using a variety of optics including the new Trijicon ACOG Reflex sight.

Of equal importance to Knight's Aimpoint mount and SureFire light mount is their vertical foregrip. If you haven't used a vertical grip on a tactical weapon you cannot appreciate its value in overall control. I have Knight's vertical foregrip on MWS units on two AR-15s and an MP5, and I wouldn't be without them. Although quite similar to the HK53, the HK33K, with its 12.68-inch barrel, requires using a full-length handguard, and no MWS is planned for full length HK weapons. Recently I attended a tactical carbine class with Sgt. Bob Kolenda of the Ovedand Park Police Department SWAT Unit in Kansas. Sgt. Kolenda brought a new HK53 to use during the three-day class and he got quite a workout with it. Not only did the class include standard positions and movements, but also more specialized techniques like the roll-over prone and supine. With its non-reciprocating cocking handle, the HK53 lends itself well to all shooting positions.

Accuracy from the HK53 proved more than adequate with Sgt. Kolenda achieving 100-yard groups hovering from 3 inches to 4 inches using only iron sights from the prone position - this from a carbine with a barrel only 8.3 inches in length and a sight radius of just over 15 inches. I have no doubt that Bob could have cut these groups in haff with a red dot sight mounted on the HK53.

Also impressive was penetration in 10% ballistic gelatin from the HK53's short barrel. With Sgt. Kolenda firing into the gelatin from 15 yards, the HK 53 achieved penetration and expansion with most .223 ammunition comparable to carbines with longer barrels, even with a Kevlar protective vest placed in front of the gelatin.

Being particularly interested to see the muzzle flash of the new HK53 at night, I was surprised to find that the improved flash hider reduced muzzle flash to that of other weapons tested with the same ammunition. Sgt. Kolenda demonstrated the HK53's muzzle flash while I photographed it. Unlike military ammunition, most commercial ammunition is loaded with flash retardants, and it made a huge difference.

Like other HK weapons, the HK53 will accept a host of HK accessories, including blank firing adapter, magazine loader and unloader, and a clip to hold two 25-shot magazines together. The HK53 can also use frangible practice ammunition with HK's new adapter system for this ammunition.


While I can easily live with HK's heavy trigger and its somewhat unconventional sight system, I find fault with the safety/selector position and its ease of operation. To improve things I would like to see an extended safety lever that would allow easier manipulation. Even more, I'd also like to see better training for all police. To that point, HK offers excellent tactical training at their facility and their instructors also travel across the U.S.

If your agency is looking for a robust, reliable and accurate tactical entry and perimeter weapon in .223 caliber, check out the new HK53.

first published in the 1999 edition of Special Weapons for Military & Police

HK 53 Specifications

Caliber 5.56mm
Ammunition Feed Staggered magazines;
25- or 40-round capacity
Cyclic rate 700 RPM
Sight Radius 15.40 inches
Weight: with empty magazine 6.73 pounds
Barrel length 8.31 inches
Overall length 22.17/29.72 inches
Width 2.05 inches
Height 8.26 inches (209.8mm)