This is a very nice adapter for the ACR. Roll pin goes in with lots of pounding, but locks up nice and tight. Worked well for the APC308 build.

Very happy with my adapter, the ACR stock is awesome on this gun (APC 308). It fits perfectly with no wiggle room and it looks great. The ACR stock also sits a bit higher than the other B&T stocks, providing a nice cheek rest which I prefer. It did cost me a fair bit more than the Haga adapter but fits much better and installation was easier making it worth the cost. Also in order to install the ACR stock to any adapter, you need a 3/16 punch to remove the roll pin from the stock hinge, don't try to use a screwdriver, I broke one ACR stock doing this :) You can also reuse the roll pin from the ACR sock and it's easier to install than the one B&T includes since it's been compressed already.

The ACR stock adapter worked like a dream...a bit pricey though