If money is not an issue I highly recommend: https://therecordist.com. This website have super accurate and high quality recordings of all your need for a gun. Foley, far, short, medium distance, burst shot, single shots, you name it. Unfortunately, there ain’t that many free gun library sound but you can get the free stuffs that available and make the most of them. Here’s a free gun pack I found: https://epicstockmedia.com/freesounds/guns-firearms/