Check out a guard made by Buckwing, I use for practice and hunting. They run $9.95 from Cabels's and I saw them at Gander Mountain. It is an elastic sleeve with 2 plastic strips sewn inside, just pull it over your arm or your coat, it will protect and also compress your jacket so it doesn't get slapped and make noise. I have one for warm weather and one to use with heavier clothes for colder weather