According to an old microflite arrow chart:
#2's are good for the following:
Target arrows
20# to 25# @ 28"
25# to 30# @ 27" and 28"
30# to 35# @26" and 27"
35# to 40# @25" and 26"
40# to 45# @24" and 25"
45# to 50# @24"
Hunting arrows
20# to 25# @26"
25# to 30# @25" and 26"
30# to 35# @24" and 25"
35# to 40# @23" and 24"
Hope this helps.
My chart is complete starting with size 0 to size 10 if anyone else needs info of a copy of the chart.