Over the past few weeks, TFB has reported several news stories related to the Heckler & Koch (H&K) MP5 platform. From H&K’s announcement of the SP5K (an MP5K semiautomatic pistol) to the U.S. market to Zenith/MKE developing an MP5SD model to add their product line-up, it is clear that even after more than 50 years of service, demand for the MP5 firearms is still strong.
Having trained, issued and carried the MP5 both in the U.S. and overseas for just short of a decade, it has always been on my list of “Grail Guns” that I would one day personally own. And with my newfound mantra of ‘suppress everything’, the obvious solution was the integrally-suppressed model – the MP5SD.
Why the SD model over the MP5K with a three-lug capable suppressor? Without getting too detailed (mostly because I’m not qualified to do so), the MP5SD is designed around a ported barrel that will keep nearly all factory ammunition subsonic. This negates the need for speciality subsonic ammunition which can be expensive, difficult to source and can have reliability issues. And I have yet to venture into the world of reloading.
In addition to the ported barrel, the suppressors that are designed specifically for the SD – and there are quite a few versions of them – have a lot of internal volume. That extra gas-cooling space helps make the MP5SD one of the quietest semi-automatic/automatic firearms ever invented.
Also, adding to the list of reasons why the H&K platform is an excellent suppressor host, all MP5 derivatives operate on a ‘roller-delayed’ blowback action. Whereas platforms like the AR15 use the expanding gases created by the explosion of powder and a gas-operated system, the delayed-roller mechanism uses the blowback force of the exploding cartridge to cycle the action. Small rollers fit inside pockets just out side the chamber, delaying the unlocking of the bolt movement rearward after the round is fired. That millisecond delay forces gases forward out the barrel and into the suppressor instead of back into the action and out the ejection port.
I am grossly oversimplifying the beauty and elegance of the MP5’s action, but if you are interested in additional details, there are many books written about H&K’s system to include Heckler & Koch’s MP5 Submachine Gun by Frank W. James.
The MP5SD is not an all-around subgun like its parent – the standard MP5. Because of its ported barrel, the SD is designed to be cleaned with a special barrel brush after approximately 500 rounds. Failing to follow a proper regimen can lead to excessive buildup of lead and powder residue, freezing the suppressor to the threads – a costly (but avoidable) mistake. Still, the MP5SD is a special purpose weapon meant to accurately and quietly sling a lot of 9mm rounds towards its target.
So, you want an MP5SD but you don’t have $40K to drop on a transferable fully automatic original? Fret not, there are a handful of builders around the U.S. that make authentic semiautomatic, suppressed, short barreled rifle SDs at a fraction of the cost.
Without belaboring the story, after months of research, lengthy consultations with friends (both internet and real) and some serious soul-searching, my journey for the best semiautomatic American-made MP5SD ended with TPM Outfitters in Carrollton, Texas.
About three years ago, our own Alex C. put together an awesome write-up and photoessay on TPM Outfitters, so I won’t even attempt to restate all of their history and capabilities here. But needless to say, these guys are arguably the best H&K builders in the business. They build MP5 derivatives that are indistinguishable from the real thing, save for engraving and that heavily-regulated ‘happy switch’ . Not only that, but they build all their own SD suppressors in-house that outperform the previous market leaders.
“We were trained under one of the best HK builders – Murray Urbach – for many years and learned the many details that may seem small to the untrained eye but makes a huge difference on the overall appearance of the weapon,” said Matt Sidley of TPM. “We make our Guns look as factory HK as possible without cutting corners.”
Obviously, this being mid-2016, there are a few alternatives to H&K available on the market when it comes to a pistol caliber carbines as a suppressor host. The first that comes to mind is the Sig Sauer MPX. But as good as the MPX is in many ways, it still operates on a short-stroke gas piston system, making it only an average suppressor host.
So my first question to Sidley was ‘why would anyone spend 2-3X the cost of an MPX on a TPM gun’? “This is a good question. Current guns on the market are much more advanced and cool, though the HK roller lock Style guns are still one of the best if not the best shooting platforms in 9mm – and they are 50 year old design,” said Sidley.
When it comes to the MP5 platform, there are H&K purists out there that demand German made guns. And the upcoming SP5K has the potential to ‘scratch that itch’ as they say. Still, the SP5K falls short in the true authenticity department and TPM is preparing to correct that problem.
We have been asked a lot of questions on HK’s new SP5K out: We will be converting them to MP5K-N PDW specs, This is what we will be converting, New HK Combat Paddle flap mag release, Changing out the Barrel to an RCM MP5K-N 1/2×32 or 1/2x 28 threaded 3 lug, remarking with double HK logo Mp5K-N and refinishing in HK Black. Its going to be $1350 for this conversion.
Where’s the review on the TPM MP5SD? After a Form 3 and a Form 4 waiting period, I expect a full writeup sometime in early in 2017. Sigh. That’s just not right. Until then, expect me to push out more MP5SD related posts. It’s therapeutic.
Besides, I’m already planning my next TPM – an MP5K-PDW.
Phone: (214) 801-1429
Fax: (972) 242-2035
1003 W. Main St. Carrollton, TX 75006-7235