I have not had to replace my strings yest as I only have about 50 bolts fired through my R29X. I have however had to have the limbs replaced at the 30 bolt fired mark. The carbon on the bottom side of one of the limbs was actually cracked and the other side was starting to de-laminiate. As a dealer, I called their support department and was made aware that there may have been a small batch that had some manufacturing issues. Ravin was great, sent a prepaid return label, replaced limbs and strings, and returned to me in less than a week. I know I did not answer you question, just wanted to provide a heads up.