For many years I used a Filson Game Bag vest for bird hunting. It is a good vest - simple and durable. Then, in October of 2005, my friend Bob Welsh of WingWorks in Hailey, Idaho sent a new vest to me while I was on the Grande Ronde for the chukar/steelhead season. 'Course I immediately put it to work for a thorough try out.
Long story short - it is the best vest I have seen or used. Every aspect of the design shows that it was developed by a real bird hunter - the load rests on the waist belt (not your shoulders), you can stow a rain jacket without stuffing the game bag full, you can put a bird in the game bag easily without shedding the vest first. It won't scratch your gun. You can put an entire box of shells in each pocket, get to them easily - and they will not fall out when you bend over to pick up a bird or scratch your dog behind the ears. And it comes with a separate lunch pocket and pockets for two 1-liter bottles - AND the bottles. The material and build quality are excellent - built in the USA. Contact Bob at Wingworks