I have some bore butter, haven't done much with it because the price is so high.
This past winter I was looking for a lube and powder good down to -30dF. Colder than that, I don't hunt.
I mixed up a recipe I found online, by weight 45% beeswax, 45% crisco and 10% olive oil. I shorthand it 45-45-10.
So I put some 45-45-10 and some bore butter on a scrap of cardboard outdoors under my boat. After about 3 days at -20dF and colder the BB was a "little bit" softer than the 45-45-10, but not a lot. The crayon type bullet lubes on the same cardboard scrap were brittle, about useless.
I found the 45-45-10 is good as a bullet lube down to -42dF (it was a sunny day, what the heck), and a whale of a lot cheaper than the bore butter.
So I stopped fooling with bore butter. One thing I did try this spring fooling with BP in 45Colt was I got my stainless gun spotless and then pre-lubed it inside and out with 45-45-10.
Shot I think 75 rounds or so. I figger if I am going to have to work that hard to clean the gun I might as well shoot a lot. turns out it was the easiest clean up ever for me using hot soapy water and patches. Getting into the action (Redhawk) with a Qtip wasn't as bad as it could have been.
So I got a little Bore Better, you can have it free if you come get it.