The clips shown in the link appear to be the later type that are almost impossible to use. I bought a batch of those a few years ago and they where so tight that they would scratch the cases and would not feed easily.
Luckily at the time I had a couple of original wartime production ones that were so much easier to use. Comparing the two shows that there is a huge difference in the type of steel used. The original is proper spring steel and will not damage the cases.
The bullets should be loaded with a downward push of the thumb. That's virtually impossible with the later almost rigid clips. I spent some time with a dremel grinder to polish the inner surface and reduce the thickness of the later clip type. It did work better; but still not as good as the original wartime production.
Luckily I was gifted a few proper clips for use in Service rifle competitions, and the ones I bought get used for dummy (neutralised) rounds for display.