Actually, the insert that ships with the Freak Jr. is .693 bore. This is a rather large bore that will allow you to shoot just about anything through the barrel. However, it won't give you the accuracy promised by a full Freak set that is properly matched to any given paint. In order to be effective, you would immediately have to buy at least one $25 insert. The Freak is a good purchase if you play at many different fields with different field paint of widely varying caliber. If you play with one paint, you should be able to get away with only 1 to 3 inserts. Keep in mind that paintballs do vary in size due to humidity, heat, and even by different batches.
Tippmann 98 Custom; 12" black CP one-piece barrel; 32 degrees RVA; Palmer female Stabilizer with ring mount;32 degrees coiled remote; Redz FlexTech 4+1 halfpack; green V-Force Shield; RT Kit; LP Valve, LP Chamber, & drilled out hammer