Vertical Grip Screw Doesn't attach to Bergara BMP Chassis

A standard AR15 accepts a 1/4-28 screw and that is what we include with the vertical grip.  Some European companies make chassis where metric thread pitches are easier to find, Bergara uses M6-1.0 thread pitch so you would have to either tap the chassis for 1/4-28 threads or pickup a M6-1.0x40mm bolt to use with the vertical grip.