I had a GT blow up last week at the knock end. I do shoot the 5575 at about 67lbs with the 28" arrow 29" draw. I personally do not think it wasa poor knock on my arrow, I have the long throat knocks. I think there was a small unnoticed crack before I shot it from smacking arrows together. It surewoke me up a bit and I try to check the knock ends more religiously now for cracks. It made an wicked sound on the shot boy, scarry, but no harm done thank god!