There is a modern DIY gun lubricant/solvent for modern guns that some folks like. STP, Kroil, and ATF in equal parts. I have tried it on modern guns and it works fine, and is less expensive enough for folks doing a lot of shooting of several guns to warrant the use of something of that sort. It also has the advantage when out in sparsely populated areas, that you can usually find the ingredients at a car parts store, or a well stocked gas station, when the local gunshop is closed and/or a long drive away. For most folks, I'd say use a commercial OTC solvent followed by a lube/rust preventative, if not a commercial all-in-one product.
For US..., as the members have mentioned, some sort of animal or vegetable fat, and some beeswax to thicken it up, works great for a bullet lube and keeping lock parts going. The amount of beeswax is based on how "thick and hard" (that sounds naughty) you want the end product to be. Lubing bullets for BP cartridge guns at least a 50/50 mix of beeswax and the fat. Probably more like 60/40. Summer and fall round ball patch lube..., I like 1 part beeswax; 2 parts olive oil. Lard works too. Very cold winter, maybe 2 parts beeswax, 8 parts fat, or even no beeswax.
Don't use paraffin in place of the beeswax, as the melting point is too low.
LD