I received my new R5M Standard synthetic stock from Edgun West about 2 weeks ago and finally had some time to install a picatinny rail. If you watch Ed's video on the new synthetic stocks, you'll see that it comes in 4 pieces which I believe are assembled at the factory and then sent out to the dealers. Maybe Ed or Brian can answer that.
Once I saw the inside of the stock and saw the brace running down the middle of the forend, I knew there was going to be some cutting and shaping with my Dremel to have the picatinny bolt and flange/nut secured at the bottom inside of the stock.
I had 2 different polymer five slot picatinny rails laying around and decided to go with the Magpul rail because I like the way it secures.

This is the inside of the stock with the front of the forend shown at the top of the picture.

This pic shows the bottom of the stock. The two screws you see is used to secure the forend to the main body of the stock.

I lined up the picatinny rail on the inside of the forend and used a permanent marker to give me an idea of where I would be cutting with the Dremel.


I then started at the front using the small cut off wheel for the dremel which was already worn down and cut several lines down the center brace but leaving a little space at the bottom so I wouldn't cut into the stock.



I then used one of the Dremel carving tools with a flat portion and cleaned off the excess and ran it against the bottome inside of the stock so I could mount the flange nut.



I then proceeded with the other side and repeated the process.

I pulled off the remaining cut pieces to clean it up.



I checked to make sure the flange nut fit flush in the hollowed out area and ended up having to do a little more shaping with the Dremel.

I lined up the the Magpul Picatinny Rail to the screw next to the trigger and the trigger guard itself to make sure it was straight before I drilled the holes for the rail.

One thing to note, the screws that come with the Magpul Picatinny Rail ended up being too short. The bottom portion of the stock is really thick. Maybe about 3/8". I had to run to my local hardware store to pick up longer bolts and had the employee match the threads with the flange nut. His CS actually sucked and seemed really impatient. I asked him for the thread size and he just shrugged his shoulders saying he didn't know and walked away.


And the final product...



Once I saw the inside of the stock and saw the brace running down the middle of the forend, I knew there was going to be some cutting and shaping with my Dremel to have the picatinny bolt and flange/nut secured at the bottom inside of the stock.
I had 2 different polymer five slot picatinny rails laying around and decided to go with the Magpul rail because I like the way it secures.

This is the inside of the stock with the front of the forend shown at the top of the picture.

This pic shows the bottom of the stock. The two screws you see is used to secure the forend to the main body of the stock.

I lined up the picatinny rail on the inside of the forend and used a permanent marker to give me an idea of where I would be cutting with the Dremel.


I then started at the front using the small cut off wheel for the dremel which was already worn down and cut several lines down the center brace but leaving a little space at the bottom so I wouldn't cut into the stock.



I then used one of the Dremel carving tools with a flat portion and cleaned off the excess and ran it against the bottome inside of the stock so I could mount the flange nut.



I then proceeded with the other side and repeated the process.

I pulled off the remaining cut pieces to clean it up.



I checked to make sure the flange nut fit flush in the hollowed out area and ended up having to do a little more shaping with the Dremel.

I lined up the the Magpul Picatinny Rail to the screw next to the trigger and the trigger guard itself to make sure it was straight before I drilled the holes for the rail.

One thing to note, the screws that come with the Magpul Picatinny Rail ended up being too short. The bottom portion of the stock is really thick. Maybe about 3/8". I had to run to my local hardware store to pick up longer bolts and had the employee match the threads with the flange nut. His CS actually sucked and seemed really impatient. I asked him for the thread size and he just shrugged his shoulders saying he didn't know and walked away.


And the final product...


