In Defense of Thermal Clips

I like them keeps us from indiscriminately spraying bullets all over the place.

I frankly have a bit of a problem with the "unlimited ammo" thing from the start.

Yes technically with the kind of technology it could be achievable. However there are two things wrong with this.

Physics which apart from the mass effect are all real world physics and purpose of a weapon.

Physics tells us that an object flying with high enough velocity will generate plasma in an air by friction. If a gun is shooting tiny grain size pellets and we use the measurement unit of grain that's a 0.064g piece of metal that means it has to have a velocity high enough to impact with enough force to do damage.
Using a few calculations we arrive at a velocity of 8km/s for that kind of bullet to have the same energy at leaving the weapon barrel as a standard AK-47.
We know that AK-47 won't penetrate some of the better body armours out there so there is no way it would penetrate a 2183 issue body armour.

So we double the energy from about 2000Joules to 4000Joules. To get there we need a velocity of 11km/s for the grain sized projectile.

And here enters recoil. Codex tells us that recoil is still the major consideration when talking about the destructive power of the infantry portable weapons. Mass Effect makes it a bit less but doesn't completely negate it. Considering the velocity of an AK-47 bullet is 0.7km/s then even if we take 50% of the recoil away the weapon would still have as much recoil as 8 AK's combined. This would explain some of the terrible accuracy at the beginning of the game but I think it just illustrates how the concept of the weapons wasn't thought through.

As for heatsinks, yes removable sacrificial heatsinks are probably the only way to get a weapon like that cool down fast enough. It's not really clear how exactly all the heat gets dumped into a heatsink but one way an internal heatsink would work is the same way as the ejectable one, allowing a portion of the coolant in it to be superheated and ejected as steam. This however would lead to faster overheating as you lose part of the coolant and also you would run out of coolant in the gun eventually.

Thanks I didn't know that. But still even 40% increase is significant. And considering that there are kinetic shields and the armour we see in games is certainly much better than current body armour so it would be more than double the energy. Especially for guns like Carnifex or the big sniper rifles with huge damage. 

Also talking about plasma, the grain sized projectile at those kinds of velocities might not even get to the target being ablated from the friction against air and turning into plasma. I think the concept is good but they should have thought more into the whole grain sized projectile part. 

Indeed, who would have thought it would be Star Wars to finally get Gun Cool down correct? The system from Battlefront 2 is basically perfect. It still uses a reload "function" but the reload simply vents the Heat. Warhammer 40k Space Marine also used this system for it's Plasma guns. It's honestly hilarious to me how multiple developers have long since figured this out, but Bioware insisted on definitively downgrading their settings technology for the sake of a pointless ammo gimmick.