Mens Baseball Jerseys have used new size chart:
new size 40 =M= former size 48
new size 44 =L= former size 50
new size 48 =XL= former size 52
new size 52 =2XL= former size 54
new size 56 =3XL= former size 56
So the former stock jerseys still use former size 48/M 50/L 52/XL 54/XXL 56/XXXL, new produce jerseys use new size 40/M 44/L 48/XL 52/XXL 56/XXXL, but they fit the same.