there were different .22 extra long

the american extra long had a 20 mm long case ( 22 lr must have a 15 mm long case)
http://old.municion.org/22altres/22ExtraLong.htm

the european 22 extra long had a 28 mm long case

http://old.municion.org/22/22.htm

this were all oldtimers from the blackpowder age outdatet by modern smokless 22 lr