u/Glad-Fail8228

Greetings. I own a Ballista Bat mini crossbow that requires half moon nocks for 4.2 mm inner diameter shaft. Ballista sells them for the astronomical cost of $1 per nock. I found some others that were terrible and literally exploded when fired. Does anyone know a retailer who sells quality half moon nocks for 6mm od/4.2mm id shafts?