How are the bullets on these belts kept together in a way that doesn’t interfere with the shooting? What connects them?
They are usually held together by light sheetmetal or plastic clamps. These days the belt 'disintegrates" as the bullets are fed into the gun, meaning that the bits of metal are simply stripped off and discarded before the bullet goes into the chamber.
The belt doesn’t interfere because it is offset from the chamber. As the bolt slides back after a round fires pawls pick up the expended cartridge and eject it and also a fresh cartridge from the belt and pull it out of the belt. As the bolt slides forward, pushed by a spring that was compressed during recoil, it chambers the new round. In order to get the process going the gun must be charged before the first round can be fired. This consists of operating the loading mechanism by pulling the bolt back manually and then letting it slide forward.
Good info here - How Stuff Works Though the part about belt feed machine guns seems to have been removed. Still some excelent graphics and info.
I had a belt of (unloaded) ammo when I was a kid. I could easily see how the metal links worked, and it’s pretty clear on the second page of enipla’s link. But I’ve never seen a cloth belt (except in movies). Since the metal links are open on the bottom, I see how the bolt can move forward without hitting it. But don’t cloth belts go all the way round the cartridge? How does that work? (Not enough coffee yet to read the whole link, and I didn’t see a clear depiction there.)
Don’t know about cloth belts, and I don’t think anyone actually still uses them, but on the Kalashnikov PK/PKM series of machine guns, ammunition is loaded in the form of a non-disintegrating metal belt. That is, the links themselves are connected (disintegrating belts use the actual round itself as part of the connection, so when the round is fired the belt falls apart) and instead of the belt being ejected as links, the entire belt comes out the other side of the receiver intact. The way this works is that on the “backwards” movement of the bolt group, claws latch on to the round (in this case, 7.62x54R, so I imagine the rim on the base of the cartridge helps)and pull it back out of the belt enclosure, and upon the “forward” cycle. push the round into the chamber.
Not quite the same thing, but I would imagine a completely enclosed cloth belt would work in a similar manner.
Cloth belts require the cartridge to be pulled backward out of the belt, moved downwards, pushed forward into the chamber, and then fired. This simplifies the belt designer’s problems, at the expense of the gun designer. It usually takes two successive cycles of the mechanism to do it. They are also liable to problems with rain and damp, and, if not classed as expendable, you have to organise sending them back to be refilled.
Well speaking of re-using cloth belts, are the links from metal belts ever caught and re-used? Or are they damaged in the loading process?
On operations they are just discarded. In peacetime many armies will send them back for salvage.
They CAN be damaged, we are dealing with a rather intense amout of heat and movement in a piece of machinery designed to chew through metal, so the primary cost of salvaging them will probably be sorting the good ones from the bad ones, more so that the actual cost of the item itself. We (Canada) will always collect spent link and catridges after training for the sake of minimizing enviromental impact ( a policy that I, being a liberal, fully support) and I believe the collected brass and link is recycled. This has been my experience while working with the US Army as well.