This was my first rocket launch in over 40 years. I started with an Estes Der Big Red Max kit and upgraded it with a Vander-Burn plywood fin/centering ring kit from Launch Lab Rocketry (https://www.launchlabrocketry.com/). I also upgraded the shock cord to 7ft of 1/2in tubular nylon from Apogee Components (https://www.apogeerockets.com). On this flight, the apogee was ~365 ft on an F20-7 but the delay was too long. When the parachute was deployed, it violently tore off the shock cord at the tabs connected to the parachute. I wanted to use this chute but had this feeling it might not end well. I should have listened to my gut. The rocket was recovered, fully intact, and flew two more times, with a Top-Flight 18in. chute. The second flight was more or less identical to the first with the exception of a perfect deployment and recovery. The third fight was on a F50-7. It's apogee was ~720ft without any issues. It actually landed about 50 feet from the pad. Thanks to CRASH (http://www.crashonline.org/) for hosting us.