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Questions & Answers
Will this fit the HK MP5 .22 LR ? I ordered the A3 tactical rear stock adapter , and it doesn't work .. thanks ! Expert Answer

The JMac Customs 1913 Adapter Fits MP5K clones (will not fit reverse stretch), but may not be compatible with some SP5K models, due to tolerances.

by Ethan, Gear Expert, September 22, 2022
Customer Reviews
Helpful Positive Review
Mp5k picatinny conversion by Davechng, December 10, 2023
Great product concept ..it gives a mp5k platform with better stock options..made of product is well made.finishing is great ..however i need slight modification to the 2 holes to make it git my turkish AP5. So i did not give this 5 stars..i fo not kn...
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5/5 found this helpful
Helpful Positive Review
Nice Snug Fit !!! by MLars, Verified Owner, November 15, 2022
I received this item along with the Jmac brace. All the components of the system were of the highest quality. This adapter was well finished and Fit very snug into the receiver so much that one the pins had to be tapped in. Some may view this as a ne...
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2/9 found this helpful
Helpful Positive Review
JMAC IS SOLID GEAR by TicoTom, Verified Owner, March 15, 2024
Another piece of quality made JMAC gear. I recommend it but it's not cheap. I highly recommend Optics Planet as well - OUTSTANDING product selection and service!
1/9 found this helpful
Helpful Positive Review
great quality by Paul, Verified Owner, November 9, 2024
This is just what I needed for my mp5 to run different folders. Did not dissapoint
1/4 found this helpful
Helpful Negative Review
Would Not Fit H&K SP5K by jasmi, December 25, 2025
Would not fit a genuine, euro-imported H&K SP5K. Adapters from B&T and CNC Warrior line up just fine, but the holes on this adapter were completely misaligned (literally half a pin-width off). Contacted JMac and they said some fitment is required, ...
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2/2 found this helpful
Most Recent Reviews
Needs work to fit by Kfin, July 13, 2026
As stated by others holes are quite misaligned… not just a little bit. U can make it work but it’s gonna take some modifying
Read All 16 Reviews
Condition:
New
Color:
Black
Gun Make:
Kalashnikov

Code: 4VI-STA-JMC0366-RSA-MP5K

MPN: RSA-MP5K

List: $99.95Save 10%
$89.96

Product Info for JMac Customs 1913 Adapter for MP5K and Clones

(R)ailed(S)tock(A)dapter(MP5K)image

Finally a way to attach 1913 style stocks/braces to your MP5K.7076 T6 aluminumhard coat/black anodized1913 milspec railincludes choate bufferadjustable cheek wieldallows attachment of pistol bracesinstalls using factory pinsfits MP5K clones (will not fit reverse stretch)Attaching a stock to a pistol creates an SBR, all NFA rules and regulations apply.Will not work with collapsible PDW style stocks or braces

Specifications for JMac Customs 1913 Adapter for MP5K and Clones:

Manufacturer: JMac Customs
Condition: New
Color: Black
Gun Make: Kalashnikov
Gun Type: Rifle
Fabric/Material: 7075-T6 Aluminum
Mount Type: AK Mount

Features of JMac Customs 1913 Adapter for MP5K and Clones

  • 1913 Adapter for MP5K and Clones

Package Contents:

  • JMac Customs 1913 Adapter for MP5K and Clones

JMac Customs 1913 Adapter for MP5K and Clones Orderable Models

List of Orderable Models

  • JMac Customs 1913 Adapter for MP5K and Clones, Hardcoat Anodized, Black, RSA-MP5K , MPN: RSA-MP5K , Code: 4VI-STA-JMC0366-RSA-MP5K

JMac Customs 1913 Adapter for MP5K and Clones Unavailable & Discontinued Models

List of Unorderable Models

  • USED, JMac Customs 1913 Adapter for MP5K and Clones, Hardcoat Anodized, Black, RSA-MP5K , MPN: RSA-MP5K-EDEMO , Code: 4VI-STA-JMC0366-RSA-MP5K-EDEMO-IN-D
  • USED, JMac Customs 1913 Adapter for MP5K and Clones, Hardcoat Anodized, Black, RSA-MP5K , MPN: RSA-MP5K-EDEMO , Code: 4VI-STA-JMC0366-RSA-MP5K-EDEMO-US-C
  • USED, JMac Customs 1913 Adapter for MP5K and Clones, Hardcoat Anodized, Black, RSA-MP5K , MPN: RSA-MP5K-EDEMO , Code: 4VI-STA-JMC0366-RSA-MP5K-EDEMO-RE-A
  • USED JMac Customs 1913 Adapter for MP5K and Clones, Hardcoat Anodized, Black, RSA-MP5K, EDEMO6, Used, Condition Fair , MPN: RSA-MP5K-EDEMO6 , Code: 4VI-STA-JMC0366-RSA-MP5K-EDEMO6
  • USED, JMac Customs 1913 Adapter for MP5K and Clones, Hardcoat Anodized, Black, RSA-MP5K , MPN: RSA-MP5K-EDEMO , Code: 4VI-STA-JMC0366-RSA-MP5K-EDEMO-SC-D
  • USED, JMac Customs 1913 Adapter for MP5K and Clones, Hardcoat Anodized, Black, RSA-MP5K , MPN: RSA-MP5K-EDEMO , Code: 4VI-STA-JMC0366-RSA-MP5K-EDEMO-RE-B
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Last updated 2026-08-26 UTC.