Used them all over the years. Still love my Swiss (
flounder) but I used Pyro, T7, now using BH209. Since I am about as OCD as one can get about my firearms being clean I have no clue about the corrosive effects of Pyro not being cleaned immediately since I would never NOT clean a firearm after it has left my house, let alone been shot! I honestly believe if I did, my old man would rise from the grave and deal me a serious blow to the rear! Ghostly butt kicking sceers me a little
As to the OP, I would personally go out and shoot that ML in with whichever you are going to use and write it down. I keep a log book myself, since I use around 100 different powders, with each rifle (cartridge based or ML) I write down the load, bullet, everything involved with any loading I do. Anyone with multiple rifles or likes experimenting with different loads with their MLers should keep a log.