I had a longbow that constantly broke strings at the top loop. I smoothed it out and still ate strings. I ended up ordering some 450plus from chad, and havent' had issues since. I could feel no burr or rouch spot. I always thought the laminations might have been shifting.

But this is after more than 1000 shots. Its not because you kept it strung. That string probably at most has 10lb strain on it strung. Probably less