The German Bundeswehr (Army) has a basic rifle for it's troops....the Heckler and Koch G36. It's kinda like the US version of the M-16....same basic character....a slightly different look.
It was designed in the mid-1990s and the Germans bought around 177,000 such rifles. Today, they still have around 167,000 of the rifle around.
It's gotten into the German news lately for an odd reason. Around two years ago, some German Army personnel in Afghanistan started to notice that in sustained battles, with a lot of firing.....the barrel got hot and accuracy decreased (so they say). Reports went out and people discussed the matter, and the German news media have attached themselves to the topic. The slant is that the CDU is responsible for this problem, and the G36 will have to be 'dumped'.
I sat and read a good bit over the weapon. There were extensive tests with the gun in the 1990s, and no issue ever got noted in the tests. Normally....you'd fire in three situations. You'd fire one round at a time, which is what the experts tend to advocate. Or you might fire a three-round sequence if you felt it was a dire situation. Or you might just cut loose and rapid-fire the whole thirty-round clip in a couple of seconds.
The last scenario is one where you might expect weapons to overheat. Toss in 110-degree temperatures.....a two-hour fire-fight....rapid-fire an entire clip over and over.....and your barrel might overheat. It'd happen with just about any brand of rifle made today.
The Germans went back and found that early in the deployment of their folks into Afghanistan....this problem didn't happen. You don't hear that in the German news media....but it might be a curious thing to know.
So I read on and there's a long discussion about bullets used for the G36. The belief is that the newer bullets are thinner on the copper-jackets.....thus able to create more heat as the round is fired.
Heckler and Koch? They feel that they've been insulted to some degree by the German news media. They made the best gun possible and tested it extensively.....so they aren't buying into the fault being on them.
I checked.....there's around forty different countries which use the G36. Even the Baltimore City Police Department uses it. It's hard to find anyone who complains about the gun. This overheating story? I would suspect the copper-jacket bullet might be the root cause.....but you'd have to do extensive tests to prove this point. It wouldn't take more than a week with a couple of guys firing and some science guys keeping track of data.....to prove the point. Oddly, you just don't see the Bundeswehr moving ahead and doing something like this.
In short, it's a political topic.....not a gun topic.