Dino,
Those need a bit more work. Big bullets can be hard to solder, the thick wire sucks the heat away so you need a powerful iron preferably with a 'chisel' shape tip rather than the pencil point ones that are used for fine soldering. It looks very much like you need to get more heat into the joint until the solder flows.
Here's one I soldered five minutes ago, yours should look similar, solder filling up the cup, forming a smooth fillet and being fully absorbed into the strands of the wire rather than sitting on the wire in 'blobs'.
View attachment 16325
If the solder runs a bit it's no big deal, you can remove it with a file later. If we weren't thousands of miles apart i'd say pop round and I'd give you some pointers.
