They made two types of pouches for the 15 rnd mags. One has two belt straps and the other has one very wide strap with a brass snap on it. The one with two straps wont fit over the stock. The other one fits. The fit is VERY tight. Have your friend put the mags in and then slide the pouch on with a little muscle. Push it all the way to the oiler can slot. Some people have actually wrapped the mags in plastic and soaked the pouch in water and then pushed it on to help it stretch. Either way, the pouch will eventually stretch out a little. Also, put a little tape over the brass buckle so that it doesnt scratch up the stock. These pouches were not intended to be put on the stock in the first place. Some GI started that in WWII.