As an owner of an H&K Briefcase, I have been trying out different setups for my SP5K-PDW SBR. One of the biggest challenges is finding a stock that fits the briefcase. I reached out to B&T and they were kind enough to lend me their telescoping B&T MP5K Stock.

MP5K @ TFB:

Stocks For MP5Ks

I am in the minority that does not like the Choate MP5K stock. I think it is hideous. It looks like some ugly thing slapped onto the back of the K.

I just do not see the appeal. It looks crude and it weighs a lot for no good reason. It looks like hammered dog feces. Look at that, ugh, I feel like I am going to throw up in my mouth.

There are so many better stocks out there. The B&T folder is only of the best aesthetics and functionality. And with the onset of Picatinny railed end caps, you can use any side folder. However not all of these work for an MP5K clone in a briefcase. First of all, you need a left-side folding stock. All the dedicated stocks for the MP5K fold to the right. The Choate and B&T folders all fold to the right. This interferes with briefcase operation. The stock hits the trigger bar so you cannot fit the K into the case.

Briefcase Compatible Stocks

I have only found two stocks that work with an H&K briefcase and they are both made by SIG Sauer. Their MPX/MCX telescoping/folding stock and their visor stock can fold to the left if you flip the folding knuckle. You can’t just throw on a left-side folding stock on the K. It will hit the release lever of the briefcase claw mount. See the photo below. You can see the release lever is longer than normal. The normal release lever is a tab on the right side of the briefcase. But since you cannot access that side, H&K welded a bar to the locking latch. So you lift it to release the claw mount from the receiver.

This is a decorative end cap designed and printed for me by Gibbous Outfitters. It was redesigned to fit the briefcase.

Here is the SIG MPX telescoping/folding stock in the briefcase. It fits but just barely. The thickness of the stock pushes against the lid but it isn’t that bad. I can still close the briefcase. The SIG Visor stock swoops down and goes around the release lever.

The problem with the SIG telescoping/folding stock is that it is a two-step operation to get it deployed. You have to collapse it to fit the briefcase. So that means you have to unfold and pull the stock out before you can shoulder it.

B&T MP5K Stock To The Rescue

The beauty of the B&T MP5K stock is that you just need to pull the stock out to deploy it. It has angled notches that raise the locking bar.

I did find a slight issue with the B&T MP5K stock and it is also a problem for the full-size MP5 B&T stock. The bars are a certain length for a decent length of pull. But that means they extend forward farther than is ideal.

If you run an MP5K vertical grip this is not an issue. See the ends of the bars reach the end of the trunnion.

If you run a wide handguard, like the Magpul MP5K handguard or Gibbous Outfitters wide handguard for the K, the bars hit the back of the handguard which does not allow the stock to close all the way. Gibbous Outfitters made H&K-styled buttpads for the B&T MP5K stock and MP5 stock.

Here is the B&T MP5 brace on my friend’s H&K SP5. He is running the KAC MP5 handguard and the Picatinny rails extend rearwards over the trunnion. So the B&T stock bars hit it, not allowing the stock or brace to collapse fully.

I did find a change in B&T MP5K stocks. On the left is the one Gibbous Outfitters let me borrow. The one on the right is the one B&T USA sent me.

Because Briefcase

I mentioned earlier that the B&T MP5K stock sort of fits the briefcase. It can if you modify it. Don’t worry, the modification is not permanent. You need to remove the right-side stock bar. Now it will clear the trigger linkage in the briefcase.

With the bar only on the left side, there is nothing to cheek for left-handed shooters. But cheeking the B&T MP5K stock bars is not exactly the most comfortable thing. Your face sits on those notches.

The B&TH MP5K stock has ambidextrous sling loop ears near the top of the end cap.

You might be thinking “That is not going to be very stable”. You are sort of right. Sure it is not as sturdy or stable as running both bars but this is a compromise for the briefcase. Most people do not even run a stock on their MP5K when they use a briefcase. I also refer you to the SAS sling method for running an MP5K without a stock. My single-bar B&T MP5K stock would be better than this.

Final Thoughts On the B&T MP5K Stock

Photo By B&T USA

The B&T stock is not cheap. It is over $500 but most accessories for roller-delayed MP5 clones are not cheap either. The stock is solid and offers a possible solution for those of you who have operational MP5K briefcases. For more information, check out the B&T USA website.