How long does it take to break in new cartridge?

I am currently using Clearaudio Artist V2.

I don't see much talk about it made me curious. Generally how long does it take to break in brand new cartridge? Or does it need breaking in?
There is no "generally". I've used dozens of cartridges and their behavior from new varies all over the place. Some change very little, if at all. Others change profoundly and may not stabilize for 100-200 hours or (rarely) even longer. Most fall somewhere in between those extremes.

This unpredictability is true even between different models from the same manufacturer... more so as between one manufacturer and another.

The experiences of others with the CA Artist V2 (if anyone happens to share that) would give you some idea. Experiences with other cartridges would tell you almost nothing.
To me at least, new carts break in a lot more than any other component. For the first few hours they actually sound broken. I can hear a difference from record to record. Like Jwm says, 50 to 100 hours and you should be OK.