Your post was a little confusing but it looks like you were worried about a .223 going too far with a miss, etc. and endangering homes. I'm trying to visualize your setup with a "big field" and "woods." What are the average distances you expect to get a shot at and are there any clear directions of fire? If not, how big is this field and how deep or wide are the woods, etc.? Are you planning on calling the coyotes in with some kind of call and/or decoy or are you just going to take shots of opportunity if you get them? Depending on your setup (especially distances), maybe a shotgun works better for you. If you post more information, someone can likely give you a more definite answer.