Adpatper for mounting the Bushmaster ACR™ stock on your HK UMP.
This aadapter is quite versatile and will not only let you mount an ACR stock on any H&K or B&T with a UMP style hinge but also on any SB adapter with a UMP style hinge. That means it should work on for any MP5, LWRCI SMG, Stribog, Scorpion, Bren, etc that has an aluminum SB Adapter installed.
This adapter replaces the entire front half of the Bushmaster ACR™ stock so that it can work with the factory UMP hinge. The rear half of the stock, cheek riser and battery storage cap are all transfered from the original part to the new adapter. The HK push button and roll pin will also be reused from your factory stock. If using the SB pushbutton the fit is currently a little too tight so I have added the option to buy the adapter with an HK button/spring until I have fixed the tolerance issues with the SB.
When installed the stock will fold but it blocks the ejection port and will not lock folded.
This part is made from 3d printed (SLS) nylon that has been media tumbled, dyed and painted black. Excessive opening and closing of the stock will cause wear that can remove the black paint & dye exposing the white nylon below.
*Bushmaster ACR™ stock not included but can be purchased separately from our accessories page.