Like all rare tagged weapons, the High Roller II can be found on any stage in Raid Mode, but there is a much higher probability of obtaining it by killing Wanted Enemies or playing The Ghost Ship / The Ghost Ship: Chaos.
It's also possible to get this weapon by obtaining high scores in some RE.NET Online Events.
The highest number of custom parts slots on the High Roller II is 6. In the PS4, Xbox One and Nintendo Switch versions, it's possible to find this weapon with 7 slots but this will only come from The Ghost Ship: Chaos.
This weapon particularly has a higher recoil than any other rare machine gun weapon due to the default high recoil on the vanilla High-Roller. Just like the rest of the rare tagged weapons, the player will move at a slower speed when the High Roller II is equipped.