How does overheat vary between guns?

[BenjaminWadeGoulart]

Ignoring the common ACE overheating settings all guns would be subjected to, is overheating of the gun varying by gun based on just the gun itself or the magazine or the magazine + barrel size? I put an MX 50 cal mod into the Virtus MCX Spear that's glitchy and too big, but I figured it would be more realistic looking with 50 cal rounds. Definitely looks the part but also doesn't seem to overheat like the MX 50. A lot of people hated the overheating, but I kinda loved it, because it was a negative attribute on something that otherwise was all positives.