The Custom AR-9 Bolt Extension is for our Folding Stock Adapter customers that have a smaller diameter BCG. The Bolt Extension diameter is .531, commonly used to fit FX9 and other AR9 builds that have a smaller diameter bolt carrier group. To ensure proper fitment, please measure the inside diameter of your BCG. Not all AR9’s require a smaller bolt extension and can work with the standard .625 bolt extension that comes with our Folding Stock Adapter.
Will not fit Gen 4 Folder
- Weight: 2.925 oz.
- Diameter: .531 in.
- Most commonly needed for FX-9’s
If you have any questions, please contact us before ordering.