I carry my extra ammo in a shooters stock pack that I purchased from eagle industries. It is made of cordura and has a suede cheek rest. It holds up to five extra rounds in the loops. Hook and loop fastners keep it on the stock. It comes in three different colors(drab, black, and woodland camo),except the suede part which only comes in black. It also has a zippered pocket. I put my cell phone in it. I'll give you the website of the company that makes it and sells them. They also make soft gun cases for a variety of different guns.
www.eagleindustries.com