AC-11 Rockwell pilot reported executing a go around while on final to avoid pattern traffic that turned base which resulted in a NMAC.

Narrative

I was on an IFR flight from ZZZ1 to ZZZ. I was cleared and flew the RNAV XX. Just inside the FAF and on glideslope I broke out of the clouds and saw the runway. I cancelled IFR with the field in sight. I switched to CTAF and announced my position; 4 mile final RWY XX. There was 1 aircraft in the pattern; Aircraft Y; who had just completed a touch and go and entered right traffic to XX. I recognized the potential for a conflict; so I made additional final calls at 2.3 and 1 nm. Just after my 1 nm call; I saw Aircraft Y start his base turn and recognized the hazardous situation. I immediately initiated a go around; turned left to avoid him; and announced the go around; left side. I transmitted; 'Aircraft Y traffic; do you realize you just turned into me?' But received no reply. After a silence; another voice transmitted; 'He's on his initial solo; so cut him some slack.' I climbed to pattern altitudes; crossed over the top mid-field; entered a right downwind; and landed safely. As I taxied clear; I saw his instructor standing on the ramp with a handheld; so I presumed he was the other voice I heard. I'm pretty confident the student was never aware of my presence or the dangerous situation he created by not extending his downwind.