KAK Industry Super Sig SB-15 Tube Review

Few products have gone from new to prolific as fast as the Sig Brace. Designed originally to help disabled vets shoot ar-15 pistols. This niche product soon found mainstream approval when the ATF approved it for use when shoulder firing a pistol.

Once the clarification letters from the ATF hit the open market and news sites stores sold out of Sig Braces as fast as they could get them. The free market reacted as it should, quickly producing lines of products designed to maximize the efficiency and popularity of the Sig brace.

While several companies rushed pistol buffer tubes to market to fill the void, KAK Industry has been a pioneer in engineering next generation components. The culmination of this engineering is seen in the KAK Super Sig Tube.


  • 6.2 oz
  • Military Hard Anodized
  • Uses a Standard length Carbine Buffer Spring
  • Over all length: 9.075
  • Once installed length: 8.45
  • Diameter of tube 1.175

KAK Super Sig Tube:

What makes it Super you ask? The super designation is assigned to several tubes offered in the KAK lineup. While the original designed pistol tubes torqued down against the end plate, the next generation designated “Super Tubes” include a traditional castle nut to secure the tube.

The KAK Sig Tube is the core item in the package. By creating a stopping point for the Sig Brace that is offset from the end plate, the Sig brace is moved back. This assists with firing when strapped to your arm and more.

The new “Super” model available uses a castle nut for increased retention and for adding standard end plates or QD mount end plates.

It’s a nice touch that even though there is an extended tube, the internals are configured to work with a standard length carbine spring. I have enough springs to stock parts for as is, who needs another one?

courtesy http://www.gunsamerica.com/blog/kak-super-sig-buffer-tube-perfect-fit-improvised-sbrs/

Length Adjustment Kit

If the only thing better than candy is more candy then the only thing better than the extended length of pull offered by the Super Sig Brace is an even longer, adjustable length of pull. KAK like me, believes in more candy and more options.

In the spirit of bringing you the sweetest products on the market, the Length adjustment kits allows you add .625 to 1.25 to 1.9 inches of more space between the pistol and the rear of the brace. As mentioned earlier for those of us with apish long arms no matter how we fire the pistol this extra distance helps.

Now you can configure your AR-15 Pistol to match your specific size or your specific needs. For example, you can run the adjustment kit short when you’re packing your pistol in a bag for hiking or truck concealment. When you’re running a LAW folder or keeping your gun for home defense, you may find the fully extended configuration is best. With the modular basis and fast installation reconfiguring your gun, takes less than a minute and requires no tools.

If your not using the LAK, the Sig Brace mounts flush with the Pistol tube. This would giving you no protection from the metal buffer. When you add the LAK kit to the pistol tube however, it’s like installing a stiff recoil pad. The Brace is solid enough that it will not bend or collapse extended past the KAK Super Sig Tube.

Sig-Brace-KAK-Buffer 024  Sig-Brace-KAK-Buffer 026

In the field

The Sig Brace is legally allowed to be fired from the shoulder according to a recent ATF letter. However, since it was not designed to be fired this way, it is not going to fully replace or offer the complete advantages of a stock and should never be referred to or modified to be a stock.

I made the mistake of installing my first Sig Brace on another brand of pistol tube. The pistol buffer was wider than the standard tube resulting in a stretched out Sig Brace. Due to the “standard” length of the pistol tube I used, the LOP was way too short for my long arms. Being 6”1’ my arms are far too long to use a sig brace without some form of lengthening. It strapped to my arm not far behind my wrist.

Switching to the KAK Super Sig Tube required me to purchase a new brace, since mine was more stretched out than hooker who finally reached retirement. You can even see in our video using the Kriss SDP that it moved around a bit while I was talking. Once the new brace was installed though it was fantastic as well as very secure from movement.

Who is this for:

Most states allow for AR pistols, and with the ATF letter you can basically build the long sought after SBR weapon system using these parts.

If your looking for a CQB gun and want to keep the Sig brace close to the rear of the gun you can do that, and will find the Super Sig Brace gives you the perfect measurements for that.

More recreational shooters or those who only own 1 AR may find that the Length Adjustment Kit with the Super Sig Brace offers the best of both worlds.

Weapon technology has been moving fast over the last few years since the assault weapons ban was lifted. KAK IMHO has done a fantastic job adapting the laws and technology to work in the favor of American Gun Owners.

Unless there is some other new shift in technology you can expect to see KAK tubes in many of the pics from the various pistols I am building.

Black Friday Sales:

Check out all the products KAK offers as well as the full list of sales for this Thanksgiving week.



About 248 Shooter

248 Shooter
Charles is the editor and lead writer for 248 Shooter, a Michigan based gun, news and gear review site. An avid student, taking classes from top tier trainers around the country. Charles is not LEO, Military or Invested in the companies he reviews. The goal of all articles is to show an gun fan enthusiasts opinions on popular products in the market. The opinions expressed are individual opinions that we hope you enjoy reading and offer a unique user perspective that may be of assistance. Charles shares his love for training as well as experience and opinions on some of the most talked about gear and products used by competitive shooters, military, leo and civilians. Ever a supporter of the Michigan economy, the hunting sports and the 2nd amendment.

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