>>32428190Before 70: 1/4096 chance of shiny
Before 70 with Shiny Charm: 3/4096
After 70: 1/1024
After 70 with Shiny Charm: 1/683
This is accounting finding any shiny. Salamence is a 1% encounter rate. Multiply these odds by 100 to find the chances of finding a shiny Salamence. I'd just hunt for a Bagon and evolve it.
Also shiny chances reset at 255, meaning every 255 you need to chain another 70 to make the odds go back up