Having re-read the post- get an AK, spend $50 to get it Teflon coated. You will be able to clean it with boiling water and a rag, or just pi** the residue out of the receiver(literally). Reserve the Savage/Rem for 300yds+. Get anything you buy Teflon coated or chromed- I'm assuming that
PR is like south Texas, with high humidity, seasonal rains, etc.? Good coatings are well worth the cost!
Not being a smart-aleck, but real planning involves supporting your system(s). The afore-mentioned petrol products, and 4 old Tshirts would last you a looooong time. Get an Otis kit for the bolt.