OK, I had to go ahead and reply so I could go back and look at your question... [8D]

You say your chub is wearing because it's hitting the string... Isn't it ON the string? (Or IN it, as it were?) Or are you meaning coming on through after the shot and making contact with the cable (which is usually what causes wear on chubs )

Irrespective... if you've got four months of solid shooting during the summer months and leading up to the fall out of a chub, you're doing pretty good. Chubs have been known to not evenlast that long.