Separate M die for each caliber.
Below is a link to Midway to use as an example.( I am not promoting them, but have not ever had an issue with them. They are just an easy way to give an example in this case.).
You can see where you can select the caliber from the box below the price listings, then select each one ya need from the caliber list.
https://www.midwayusa.com/product/10...expander-m-die
Here is the list for NOE expander plugs for pistols to use in your Lee Universal expanding die: http://noebulletmolds.com/NV/index.php?cPath=89
Here is the list for NOE expander plugs for rifles to use in your Lee Universal expanding die:
http://noebulletmolds.com/NV/index.php?cPath=88
Hope that helps out a bit.
G'Luck!