The HK MP5 SD6: Good, Clean, Sexy, All-American Fun

MP5SD

The Heckler & Koch MP5SD has been the western world standard for a suppressed submachine gun for around three decades.  While the suppressor design is dated by contemporary standards, it remains one of the most effective designs still in production.  Particularly with subsonic ammunition, it is very quiet indeed.

I’ve had the pleasure of firing fixed and collapsing stock versions of the MP5SD, as well as most other versions of the MP5 family, suppressed and unsuppressed.  They are sturdy, reliable, accurate (they fire from a closed bolt), and easy to fire well, thus their popularity with special forces and law enforcement.  For the average citizen, however, there is a problem: it’s nearly impossible to own any MP5, but the MP5SD is doubly difficult.

In 1986, Democrats, at the last second, slipped through a ban on all machine guns, adding to the Firearm Owner’s Protection Act through legislative chicanery.  Only those weapons legally possessed and registered with the federal government prior to May 19, 1986 are still lawful.  This means that no citizen may own or transfer a machinegun of any kind manufactured after May 19, 1986 (18 USC 921).  So, no new machineguns for citizens, though law enforcement may, of course, purchase new weapons.

Used MP5s that fit the legal criteria for ownership are currently selling in the tens of thousands of dollar, and the SD models, even more, but they’re exceedingly rare.  But that’s not all.  Even if one has the wherewithal to buy one of these older guns, there is a $200.00 excise tax for the weapon, and an additional $200.00 excise tax for the suppressor even though it is an integral unit that can’t be removed and attached to another firearm.  All of this is part of a lengthy process requiring the filing of substantial paperwork, which includes fingerprinting, being photographed, a very intrusive FBI background investigation, and local checks and certifications of various kinds.  The BATF also demands to know where it will be kept and the manner of storing it, and no one can carry a machinegun across state lines without prior and specific federal government approval.

If it sounds like the federal government is trying to make owning a machinegun so annoying and difficult most people won’t try, you’re catching on.

Heckler and Koch manufactured a semiautomatic only version of the MP5–the HK 94–with a 16.2” barrel and an overall length no less than 26” to comply with federal law.  

Weapons with shorter length and shorter barrels are treated exactly as machine guns.  However, President George H.W. Bush (the first one), in 1989, put into effect an import ban on all such foreign-made weapons, including the excellent and popular HK 94, a semiautomatic only version of the MP5 with a 16″ barrel.  A variety of American companies have produced limited numbers of semiautomatic MP5s under license, but not in great numbers and they are relatively uncommon.

Citizens exposed to the MP5 family through TV and the movies, and wanting to shoot these weapons, have, until recently, been pretty much out of luck.  Fortunately, H&K has partnered with Walther to produce the MP5 SD6, which is essentially a replica of the SD model, and the MP5 A5, which is a replica of the MP5 with a Navy model forearm, and a non-integral, non-functioning “suppressor” attached to the barrel.  Actually, real MP5s have barrels of about 6”, but to comply with federal law, the MP5 SD6 and MP5 A5 have barrels of 16.1”, both covered in part or completely by non-functional suppressors, which are essentially barrel shrouds.  The good news is no federal paperwork and excise taxes are required to own these .22LR replicas.

MP5 SD6, Right Side

This is a HK MP5 SD6, seen from the right side with the stock fully extended.  In this configuration, the weapon is 33.8” long.  Comparing the SD6 with the SD depicted above, it’s easy to see that the primary difference–other than caliber–is the suppressor can of the SD is substantially shorter than the non-functional suppressor of the SD6.  This is due to the federal minimum barrel length requirement.

This is the same weapon with the stock collapsed.  In this configuration, it is 26.8” long, .8” longer than the legal minimum.  For those familiar with the MP5, another dead giveaway is the long slot in the side of the magazine, a feature not present in 9mm magazines.  Other than that, the weapons are virtually identical in size, weight, balance and general appearance.

This .22LR copy of the MP5 is not in any way cheap.  It appears to be made with the same materials and the same attention to function and purpose as the 9mm MP5 family.  The balance is very similar to the SD, as are all of the dimensions, control placement and function, and the fit and finish.  There are several other MP5 clone .22LR weapons on the market, and while they bear a reasonably close resemblance to the real thing, they aren’t nearly as accurate as the SD6, which feels, for all intents and purposes, like the MP5SD.  Weighing 7 pounds without a loaded magazine, the SD6 is also quite close in weight and balance to the SD.

MP5 SD6, Left Side

The SD6 does not feel like a cheap, knock off .22, but like what it is: an expensive, substantial, serious, well engineered and well made carbine.

In this collapsed view of the left side, all of the familiar MP5 features are evident.  The sling attachments, the stock lever, the paddle-type magazine release (it is mechanically linked to an appropriately placed push-button magazine release of the type generally preferred by Americans), the distinctive sights, and the cocking handle common to HK firearms.

ACCESSORIES:  These are the accessories I’ve added to the SD6.

Spare Magazines:  Magazines are available from HK Parts, currently at $50.00 each.  I was able to find three magazines in a small shop in Wyoming for $30.00 each just as the recent firearm, ammo and accessory shortages started in earnest.  The SD6 is furnished with only a single magazine.

These are the only magazines that will actually fit the SD6.  There are similar looking magazines on the market for the clone versions, but they do not fit the SD6 or the A5.

Scope Mount:  There are many claw-type scope mounts on the market, but according to HK Parts, they have the only mount on the market that will actually fit the SD6 and A5. I suspect they’re right about that.  My local dealer tried several aftermarket mounts on my SD6, but to no avail.  They looked the part, but lacked the engineering precision to fit and work properly.  Unfortunately, the HK mount costs $100.00, and on some weapons might require a bit of fitting–my fitting was minor and easily accomplished with the gentle and brief application of a Dremel tool–but it fits tightly and is quite solid.  Depending on the type of sight chosen, there might be room to attach 90° mounts for lasers or flashlights, but I’ve decided not to clutter the lines of the weapon with more than the mount and red dot sight.

H&K could have easily specified an integral accessory rail or rails with this design, but I suspect they chose to retain the authentic configuration of the weapon system.  There is something to be said for authenticity, but the lack of such rails is one of the inherent weaknesses of the original design too, particularly with the contemporary state of the accessory market.

Red Dot Sight:  With age, I’ve found my eyesight to remain quite functional, but it is no longer as sharp as it once was, so I’ve come to appreciate red dot and laser sights.  I chose a Tasco sight that is at once rugged, simple, and inexpensive.  It has an 11-position rheostat that allows adjustment for any lighting condition.  The windage and elevation adjustments are clear and positive, and the red dot small, clear and easily seen for ranges out to and including 100 yards.  For the 50 yard effective range of the weapon (yes, it will easily make hits on a man-sized silhouette target at 100 yards), the dot is well sized and easily seen.  The $34.99 price is also welcome.  It’s not hard to spend easily as much on a sight as on the weapon.  However, for a weapon that will be relegated to occasional training and fun shooting, money spent on a far more expensive sight would not produce better results or greater pleasure in shooting.  The sight is easily and quickly mounted and sighted in.

Scope Covers:  Another advantage of the Tasco sight is that it accepts common and inexpensive Butler Creek scope covers.  Many, more expensive, “tactical” sights have oddly or irregularly shaped eyepieces and objectives, making scope covers hard, even impossible, to find at any price.  This sight takes an 11 eye and a 13 objective cover at $9.99 each.  

Magazine Loading:  Magazine capacity is an honest and functional 25 rounds, though I prefer to load no more than 23 (old habits die hard).  The owner’s manual specifies “high velocity” ammunition, though there is an allen bolt under the stock cover that may be adjusted for different types of ammunition.  I suspect that most owners will simply use high velocity ammo, as I do, and have no need for adjustment.

MP5 SD6 .22LR Magazine

The magazines are sturdy and well designed with tabs on both sides of the magazine that make loading easy and fast.  It is best to pull down the tabs only enough to allow each individual round to slip into place.  It will probably be necessary to gently push each round against the back wall of the magazine as it is inserted.  Pulling the tabs down and dropping in multiple rounds will allow them to fall into the magazine at odd angles, requiring some fidgeting, shaking, and likely, cursing, to align things.  Once all rounds are in the magazine, it’s a good idea to gently whack the back against something to be sure all the rounds are seated comfortably and will feed reliably.

Insertion of magazines into the magazine well is positive and easy, but one must be careful not to torque the magazines to the front, back or sides.  The polymer body of the magazines will produce considerable friction if not inserted at the correct angle.  It’s not hard to get the hang of it.  The same procedure applies to removal of magazines.  I’ve accustomed myself to using the paddle release over the years and have no difficulty manipulating that while simultaneously getting a solid grip on the magazine, though some shooters will likely prefer the push button release.

Do not expect magazines to drop free as most handgun magazines do.  In the military context for which these weapons were originally designed, keeping one’s magazines, rather than dropping them on the battlefield, is a primary consideration.  With that in mind, having a firm grasp of a magazine as it is coming out of the magazine well is a rational practice.  I suspect that with thousands of rounds through the weapon, magazines will begin to drop a bit more freely.

Shooting:  Taller shooters will find the stock a bit short, and a fixed stock will be little better.  These weapons–the original, 9mm weapons– are designed to be fired by people wearing heavy body armor and other tactical gear.  Even so, it’s not difficult to find a reasonable cheek weld.  Using only the iron sights is somewhat more difficult for larger/taller shooters as they have to scrunch down quite a bit.  The SD6 is muzzle heavy, and its overall weight and balance make aiming and shooting a pleasure.

With the “suppressor can,” one is tempted to expect little muzzle flash and report, but the little carbine sounds like any .22, making a characteristically sharp and short “crack.”  There is virtually no recoil, which is hardly unexpected in a carbine weighing around eight pounds loaded and a muzzle heavy balance.

The trigger pull is about seven pounds (the manual specifies from 6.5 to 8.4 pounds), and while not like that of a fine, bolt action rifle, is relatively crisp and positive.  The trigger blade is polymer, relatively wide and comfortable.

Accuracy is on a par with most common .22LR semiautomatic rifles on the market.  Two to three inch groups, offhand at 25 yards, were easy to accomplish.  This is not a tack driver, capable of the kind of accuracy one can find with a 20”+ heavy barrel and a quality scope, but it’s on a par with other .22LR rifles in its class, such as the S&W .22LR caliber AR-15 copies.  

The SD6 is great fun to shoot; what more reason does one need to buy a firearm?  That’s why I got it, that and the fact that when I chanced to see it on my local dealer’s wall, I realized that if I ever wanted one of these rifles, it might well be my only chance.  It was the only copy he had seen in many months, and he has no idea when–or if–he’ll have another at any price.  Were it not for the status quo, I likely would not have bought it, but I’m glad I did.

Why is it fun?  It’s accurate, and thus far, completely reliable, and the magazines function perfectly. It handles almost precisely like the real 9mm weapons I used for so many years.  I could, if I wished, go through the process and buy an actual machinegun–if I could find an MP5 in decent condition and didn’t have to pay as much as some small homes for it–but that’s a great deal of time and trouble (I’m probably on enough government lists as it is), and when ammunition once again becomes reasonably available, what I’d pay for an MP5 will buy enormous quantities of ammunition.  I think I’d rather shoot as much as I’d like.  I’ve fired more than enough fully automatic weapons, thank you.  As an instructor, it’s also fun to give new shooters a taste of weapons of this type.  Such delighted smiles!

Cleaning: You suspected there was a downside, didn’t you?  There is, but it’s not horrible by any means.  As you can see from the photograph, the SD6 breaks down into essentially five major parts or groups of parts.  From bottom to top, the trigger group, which includes the hammer; the bolt groups which includes the bolt, ejector, the actual receiver in which the bolt cycles, and the attached barrel, which is quite small in diameter; the collapsible stock, which appears to be no different than MP5 stocks; the upper receiver, into which the receiver group snuggly slides.  It incorporates the magazine well, the cocking handle, the sights and the forearm. Finally, there is the suppressor can.

The instruction manual recommends only the most cursory disassembly, consisting of removing the two pins, which are simply pushed through the receiver and removed.  By pulling the collapsing stock housing straight back off the receiver, the trigger group can be pulled down and off the weapon.  It is here the manual recommends stopping.

Cleaning the bore must be done from the muzzle, so one must be careful not to damage it.  It is possible to clean the bolt and its raceways, etc., but there is little room to work, and with this level of disassembly, it is impossible to clean the weapon completely.  By unscrewing and removing the suppressor can, the entire silver receiver/barrel group can be easily withdrawn from the rear of the upper receiver.  It is much easier to clean the weapon properly when it is broken down as shown.  Even so, a great many Q-tips are required, and must be inserted though various slots, cutouts, and other spaces to get all of the powder and grit .22LR ammunition produces in such quantity.  There is a small protrusion on the top of the silver receiver attached to the bolt (it is this with which the cocking handle interfaces).  To hold it back for cleaning, I used a common spring-loaded woodworking clamp with padded jaws.  The manual does specify precisely where to oil the weapon and how much to use.  That too is easier with this level of disassembly.

I’m not a clean freak when it comes to firearms, but as long as I’m doing the job, I believe in doing it well.  At this level of disassembly, there are no tiny screws or springs that shoot off and immediately disappear into alternate dimensions or black holes.  In order to remove and completely clean the bolt, it will be necessary to remove five allen bolts/nuts.  That won’t be a daunting task, and I doubt it will be absolutely necessary until I’ve fired many thousands of rounds through the gun.  However, the weapon is not nearly as easy to clean as a S&W M&P 22-15, which breaks down almost exactly like an AR-15 and is actually easier to clean completely.  I estimate I was able to clean it about 95% as well as I prefer to clean my weapons, and the effort involved wasn’t terribly demanding.

The black tube extending from the forearm appears to be a sort of guide and shroud for the slender barrel.  The barrel is actually that thin, silver tube.  The front of the suppressor can, which is steel and very solid, screws onto the end of the barrel, no doubt stabilizing it–necessary because of the thin barrel–while simultaneously holding the receiver group tightly in place. There is supposed to be a specialized wrench included with the weapon for removing and tightening the suppressor, but mine had no such wrench.  I was able to remove the can by hand, and after settling it hand tight, I used a rubber strap wrench to tightly it very slightly more (the manual suggests such tightening).

Reassembly is very easy.  Slide the silver receiver group into the upper receiver; screw on and tighten the suppressor (some Q-tipping will be necessary at the slightly recessed muzzle); replace the trigger group; replace the collapsing stock, insert the two pins (the pin forward of the trigger guard is shorter and smaller in diameter than the other pin, making it impossible to insert the wrong pin in the wrong hole), function check the weapon, and reassembly is complete.

Final Thoughts:

I paid about $570.00 for the weapon, though I’ve seen it advertised as much as $30.00 less.  However, considering the scarcity of most weapons of this type, one might expect to spend more, perhaps considerably more, if one can be found.  Is it worth it?  Other weapons of this type cost about the same, particularly during the age of Obama.  If you’re handy with firearms and don’t mind a bit more disassembly and cleaning than some other designs require, it’s an interesting gun with a long and distinguished lineage on the side of freedom.