Like @justin davis said, center fire cans are considered self cleaning. 300 rounds wouldn’t even be on my radar. However, Silencerco told me to mag dump 556 in my hybrid and specwar to get them hot enough to clean them if I felt they needed cleaning. I think if you are shooting enough rounds consecutively with your saum or prc it should get hot enough to burn out any buildupDont know. I was just thinking about if I should clean it. I have around 300 rounds through it with a 20" 7 SAUM and 7 PRC.