The advantage that mutton tallow has over lard is:
I. I tends to remain stable longer than lard and does not become rancid.
2. It is sticky as all get out and helps the lube stay on the bullet.
It is not readily available so I use Dick Dastardly's pearl lube formula.
I part soy wax, 1 part toilet bowl wax(not really a wax anymore but it works. Avoid the ones that have fiber in the compound. Makes a real mess)and 1/2 part of vegetable shortening. Adjust quantities to suit you hardness criteria.