Kroil - fantastic stuff, a little pricy though
This stuff has been around since 1939, it works! I like to apply then heat up the screws area with a torch, not too much but enough to foster a little capillary action. It works so well I’d not be too surprised to come back and see the screws just lying on the bench, undone by themselves! Lol
This is my 89 yr. old Colt. No boogered screws on my part. Would you believe about $30 a can?! But you’ll probably have it a couple years anyway. It’s a must have for my kit. We used it on a crusty 106 yr. old Webley not long ago. A stuck damaged head screw, success. The feeling of freed screws is totally worth it.
Now to figure why the cyl. has side to side play with the hammer down…