JMac - MDi-co

ST-6 for 4.5mm Folding AKs

(7 Reviews)
Current Stock:
4.02 Ounces
SBA3 Brace

(S)keletonized(T)ube(6)inches long and 6 positions with SM-4.5 (not assembled)

This M4 tube adapter replaces the standard buffer tube to ensure the stock folds as flat as possible!

Fits most M4 style stocks/braces 

Lightweight and Rigid

  • Integrated QD Sling Sockers
  • 6” Length
  • 6 positions 
  • 7075 T6 Aluminum
  • Type III Hardcoat Anodized

SM adapters utilize the factory rear trunnions and eliminate the need for additional adapters or folding mechs. 

This version of the SM stock/brace adapter is specifically made for 4.5mm pin folding stocks. 4.5mm trunnions can be found in the SLR 104/106/107 UR/CR/FR. This stock adapter, like the rest of the SM line, will allow you to install all of our Arm Bar and Stocks as well as SIG style stocks. Cheek wield is adjustable by moving the stock/brace up or down on the adapter.

  • 2 height positions
  • Compatible with all of our SS/AB/ST options as well as SIG stocks
  • 7075 aluminum
  • Black hardcoat anodize finish
  • Includes mounting bolt for lower hole

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.

Reviews (7)


Written by T.A. Sheppard on Apr 9th 2022

I’m extremely impressed with the fit, finish and ease of installation of the ST-6. It also make my AK look even more Awesome!

The best

Written by Zach on Nov 25th 2021

I don’t have a lot to compare it to because my only ever stock adapter I’ve used was also jmac customs but I like this one better than their buffer tube adapter, which is also badass. I was worried it would look weird but it looks super cool with the two stocks I’ve tried it on(Magpul ctr and b5 bravo). Both fit really snug on it. It feels solid also, even though it’s only really touching the bottom and top of the inside of the stock. The finish is as badass as it could get.


Written by Joe on Nov 6th 2021

Tried many different stock options and this is by far the best. Feels quality and looks badass. This one is staying on for good!

Great pro

Written by Kyle on Nov 3rd 2021

Smooth edges , nice deep black finish and functional as it should be . Oh yeah , it looks cool too and that’s all that really matters!

almost perfact.

Written by Jake on Aug 20th 2021

This is a great adapter that allows you to retain the ability to fold your stock but also allows you to use an m4 style stock. it was very tight but with some minor sanding, I was able to get it to fit.

Great Option for the PSA - 103, but some fitment may be required

Written by Eric Wagstaff on Jul 19th 2021

Will this work on PSA-103, yes but some fitment maybe required. You may luck out based on your rifles tolerances but on mine the adapter wouldn't even fit onto the hinge, nor would PSA hinge pin fit. I'm not sure if PSA 4.5mm spec is smaller vs JMAC adapter is slightly larger, but I spent a few hours grinding and sanding the adapter to fit in the PSA hinge slot and then took a 11/64 drill bit to ream out the pin hole. After I got that all done, it fits and locks up beautifully. Now with a Magpul CTR stock it looks and feels great. If you want to replace the factory stock and don't mind some fitment work, if needed, this is a great option especially to not have a bulky M4 adapter/buffer tube setup.

4.5 mm stock ADAPTER

Written by Sam on Jun 18th 2021

Fits my PSA ak-103 perfect. Great drop in piece of gear if you are looking to get rid of the 103 folding stock.

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