How does overheat vary between guns?

[DJ-Reticuli]

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.

[Drofseh]

The amount of heat generated is based on the ammunition, the faster a bullet is and the heavier it is the more heat is generated per shot.
How quickly the gun heats up is based the mass of the gun, the heavier a gun is the more heat is required to raise its temperature.

A fast heavy bullet generating a lot of heat in a lightweight gun that doesn't have much ability to soak said heat will quickly find itself at a high temperature.

[rautamiekka]

I think you mean the MMG variant (SIG Sauer MG 338) which is 338NM.

It seems the superior thermal transfer of the latter is due to the latter being forged steel instead of cast or milled. It seems forged steel has a very different structure. And since it's simultaneously stronger, you can use less of it, which is how the latter got lighter.

Sources:

• Comments at https://www.reddit.com/r/ForgottenWeapons/comments/17p09xt/mg338_is_very_huge/
• Some answers at https://www.quora.com/Why-do-forged-metallic-parts-have-a-higher-rate-of-thermal-expansion-and-contraction-than-the-casted-machined-one
  • https://www.quora.com/Why-are-forged-metals-more-ductile/answer/S-Sreeram-3 (the answer is paywalled, but you can see the important parts of it without)
  • Automated AI answer, copypasted here: https://gist.github.com/rautamiekka/5365a0cf183b0574c4fa47e3b31613fa

[Drofseh]

If you want to look at the code you can see how the heat is generated from the projectile here:
https://github.com/acemod/ACE3/blob/master/addons/overheating/functions/fnc_overheat.sqf

And how the heat energy gets applied to the weapon here:
https://github.com/acemod/ACE3/blob/master/addons/overheating/functions/fnc_updateTemperature.sqf

If the weapons don't have ACE specfic values for the mass of the bullet or the barrel then they are estimated based on the hit and caliber of the ammo, and the mass of the weapon.

[Drofseh]

I am not super familiar with how ACE Medical works, but I believe ACE takes whatever damage the engine says was done and bases it's wounds off that.