Gun grease definitely has applications such as your BCG, trigger and slide or bolt rails, but I prefer a good moly grease. I’m not a fan of Lithium grease for guns. KG makes the best dry lubes I’ve ever used and the best moly grease as well. That’s my trigger dope. As far as a real world protectant, Marine Tuff Glide has kept all my hunting rifles and shotguns in good shape for about 30+ years. Anything steel that you need to weatherize would benefit from a coat of this.