JMac - MDi-co

1913 Adapter for MP5K and Clones

(5 Reviews)
Current Stock:
2.80 Ounces


Finally a way to attach 1913 style stocks/braces to your MP5K.

The RSA-MP5K adapter will fit the MP5K and clones. It has a picatiny rail machined on the rear which allows you to install our 1913 style stocks/braces!  

  • 7075 T6 aluminum
  • Hard coat/black anodized
  • 1913 milspec rail
  • Includes choate buffer
  • Adjustable cheek wield
  • Allows attachment of pistol braces
  • Installs using factory pins
  • Fits MP5K clones (will not fit reverse stretch)
  • May not be compatible with some SP5K models, due to tolerances.

 *Not compatible with CNC Warrior 1913 stocks/braces.

 *Will not work with collapsible PDW style stocks or braces 

Attaching a stock to a pistol makes it an SBR and requires NFA approval. You are responsible for knowing and following your local/state/federal laws!

JMac Customs LLC is not responsible for the end users misuse of our products.


If you have misplaced or damaged the hardware you received with your item you can find replacement hardware here 

Reviews (5)

1913 Adapter Mp5k

Written by SETH on Mar 1st 2024

Awesome! Easy to install and works perfectly!

1913 adapter for MP5K

Written by Todd m on Sep 20th 2023

Great quality piece for the AB-8R and folding mechanism on the smaller K model. Perfect fit!

1913 ADAPTer for mp5k

Written by Christopher Myers on Jul 18th 2022

Very clean and proper fit. High quality aircraft aluminum. Black finish clean coating.


Written by Joe Yarckin on Aug 30th 2021

Awesome product great look and perfect fit!


Written by David on Jun 17th 2020

If you are SBRing an SP5K, this is a great adapter to allow you to use Sig folding telescopic stock or any other stock that utilizes 1913 rail. This adapter allows you to adjust the height of your cheek weld to permit ideal use of iron sights or an optic. Just put the stock higher or lower based on what you are using. Excellent adapter. Fit is snug but why would you want it loose? I'm no fan of wobble and so I find this to be of excellent quality. Honestly, great balance of aesthetic and ergonomics in my opinion.

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