They all run pretty much the same general operating temps, which is impacted by your skill in tuning, the way they are cowled, and the way they are operated. 100C to 155C is a good operating temp range. Higher or lower and you're doing something wrong. Don't use a temp gun. They (engines) are not water cooled so they do not operate at the same temperature all the time. A temp gun only provides a rough temperature for the "now".

Do a search for more detailed info. There's a lot of it out there. That you mentioned using an aiming point indicates you're a newbie and therefore need to do some learning.