RCBS has fantastic customer service. Just email them or call and leave a message. They'll get back to you in a couple of days.RCBS replaced the plastic parts in mine at no charge. All I did was write a letter, not many do that anymore, told them what was wrong and gave them my address and phone number and asked for their advice. They sent me two of each sm and lg.
However, their quality has started to wain in the past few years unfortunately IMO. The replacement parts I've received have been of lesser quality metal, almost like pot metal and tend to not last, even the plastic parts are made less durable. I finally replaced my .223 and 30/06 dies with Hornady and have been happy I've done so. The RC press I have has been a tank and never given me any issues. Of course, I've had it for almost 30 years.