Grey Solutions oils all of our firearms with Mobil -1 synthetic motor oil. One quart of Mobil-1 is about $9.00 and should last you a very long time. Mobil-1 is designed for use in race cars that operate at very high temperatures so it will keep your gun in operating perfectly. Weight of the oil does not matter. Whatever you have on hand is fine.
Buy a small oiler bottle like this to put the Mobil-1 in:
6 Pcs Needle Oiler, Oil Applicator (1 OZ), Gun Oil Bottle with 1.5 Inch Stainless Needle Tip, 18-Gauge Tip Applicator Bottle with Funnel for Multi-Purpose Use https://a.co/d/d5UbuhA
Also wear latex gloves when applying the oil as all oil comes with a cancer warning label.
Keep your head down and keep the faith.