One of my offseason projects this year is modifying a Benelli M4 Pistol Grip Stock that I purchased for $40 to fit my Super Black Eagle. If anyone is interested, it worked pretty good. There are some tricks to modifying the stock, but if you have the right tools, it is easy.
Required:
Small Phillips head
Gun oil
13 mm deep well socket
6” extension
(2) 8x1 nuts

- remove the M4 stock recoil pad (put gun oil on the access holes for the screwdriver)
- remove the nut on the butt pad end of the all thread that keeps the sling mounting bracket in place
- from the receiver side of the stock, use the extension and socket to lock the 2 nuts together on the threaded bolt used to hold the sling bracket in place
- use the extension and socket to turn the threaded bolt counter clockwise with the nuts that were locked together
- this will allow the washers to drop out the butt pad side and will completely remove the bolt holding the sling mounting bracket in place
- install on an SBE 1 using the sling bracket to run the threaded end of the recoil spring tune through and attach tighten using original nut and 13mm socket