Gold Crown III drop-pocket tables can damage a cue-ball
I have seen this damage before and the person " people " swore up and down that it was from their Sledgehammer, I told that it wasn't and told them to look for a loose screw or bolt holding the rubber pockets in the corners. Sure enough, 2 loose screws and if you look at the other balls you will probably find the same marks on them too!!!!
I tend to agree with no-sho. I've played on a lot of Gold Crown III tables in my time, and at least with the drop-pocket version, my experience with them reveals a flaw in their design. The pocket buckets are held in place with two recessed screws, that are in-line with the travel of a ball into that pocket. Meaning, if you slam a ball into the back of the pocket -- on the proper angle into the pocket that makes the object ball slam head into that screw hole -- you will have an opportunity for that ball to hit the head of the screw. It doesn't matter that the screw is recessed into the pocket-bucket's plastic; if you hit it hard enough, you can compress the plastic and make the ball "bottom out" onto the head of the screw. It actually makes a very distinctive sound when it happens; not the normal "thunk" with a ball hitting soft plastic, but more of a "clack" sound.
I've seen this type of "comma" (or "C") damage on object balls as well, and in almost all cases, it was the pocket-bucket-support screwhead that caused it. There's actually a rubber or plastic plug that's supposed to cover that screwhead, but this plug almost always dislodges and falls into the pocket upon hard impact, thus most of the GC-III drop-pocket tables almost never have them intact. A very poor design if you ask me.
I'm not doubting that some Phenolic tips can cause this type of damage, but I am sure -- from personal experience -- that certain drop-pocket tables can cause this. I for one use a break cue (Fury JB series) that has a special "soft" Phenolic on it -- installed by a local cue luthier -- that's guaranteed to be softer than the cue-ball material. It's soft, but resilient -- it "springs back" and won't mushroom. (I had this special soft Phenolic installed because I was mushrooming the stock carbon-graphite tip/ferrule installed on the Fury JB series.) However, I wouldn't doubt for a second that there's Phenolics out there that are as hard as a rock, and would cause this kind of damage. I would suggest, though, that folks inspect their tables -- especially if they are the drop-pocket type with plastic buckets -- to see if there are any visible screwheads, recessed or not. If so, these could be the culprit!
I hope this is helpful info!