I had the very same problem. Benelli makes a superb shotgun and one heck of a sorry ****ed excuse for an Owners Manual
If you have not already done so it would be worthwhile to review, refer to and also save to disk the following USMC Technical Manual (TM 10698A-10/1):
http://www.militec-1.com/firearms/manual.html
Below is what Benelli USA Customer Service had sent me regarding how to remove the stock from the Benelli M4. As most of us have discovered, this information is not readily apparent when looking over the shotgun for the first time and also after reading over the Owners Manual.
Note - removing the fixed stock w/pistol grip is best done with the help of a strong friend as you will need to turn the stock while holding the rest of the gun in place. I would not recommend using a vice to do this as you may damage the weapon by exerting too much pressure to the loading port or other portions of its anatomy.
1. Push trigger group pin located over trigger group on the side of the gun from the right side through to the left. It will not come all the way out.
2. Pull trigger group out from the receiver, it does not have to come all the way out.
3. Grab Stock and spin in Counter Clockwise and remove.
4. Installation of the Collapsible stock is the reverse of removal.
To collapse stock.
Push button in and hold - turn stock butt to the left and push in. Turn to right and then slide off for removal.
Regards,
Martin
[ 07-06-2006, 09:52 PM: Message edited by: unkamartin ]