I've combined thoughts regarding the Lee die set. The initial Value tends to make them glimpse more affordable BUT eventually, after needing to buy a independent expander die (IMHO, you'll need an expander die since it will make putting the bullet into the case a no brainer) and crimp die https://jaredcmzlw.ageeksblog.com/37376862/facts-about-300-blackout-projectiles-revealed