It won’t cause problems with reloading?
I'm guessing that was originally factory loaded with a HBWC? If so, that is actually brass made for wad cutters. Sometimes there is actually 2 cannelures on the side of the case. Wadcutter brass has a thinner case wall so the soft wad cutter isn't swagged down as its seated in the case. The cannelure prevents bullet setback
The bullseye shooters hunt for this brass because the only way they are able to get it is by firing factory loaded semi-wagcutters.
First, it does not mean that. Some factory ammo has wadcutters and no cannelure. And some factory ammo has cannelures and no wadcutter bullets. Remington HBWC ammo does have two cannelures. One can google it.
Semi-wadcutters are NOT wadcutters. The only way to know for sure is to shoot ammo loaded with wadcutters, and depending on the source, it might or might not be special brass.
Have you ever had it happen?Cannelures can cause problems after a number of reloads if you get brass separation in the chamber of a lever gun. In a revolver it is easier to get the brass “ring” out of the chamber in a cylinder. In a lever gun chamber it can be a real bear to get out.
Have you ever had it happen?
I have shot a boatload of rounds with cases that have cannelures and have never had an issue.
or give them to someone else who will.
My conclusion is that they are mostly decorative.