here is A QRC
Kevlar:
Pros: 6x stronger than steel, extremely heat resistant Because of these qualities Kevlar shock cords generally outlast the rocket.
Cons: Somewhat Abrasive getting the Braided Variety may help. Since kevlar is very strong, it is stronger than your body tube, hence at very high deployment velocities(60fps-90fps) It MAY zipper your tube:blush:
Nylon Elastic: Pros:Flexible and soft , very unlikely to zipper because of this.
Cons: Not Very heat Resistant, i have a model that uses one and i put a healthy amount of wadding in and after 3 flights the cord has nearly burned thru. However there is a solution, Nomex Shock Cord Protecters, Madcow and CWD both sell them and CWD has Very Long versions, however this my get expensive .
Elastic: this is nearly ruled out in the MPR range there are no true notable advantages, and they do not last very long nor are very strong.
MOUNTING:
The Classic Estes Tri-fold mound: This Is Typically preferred to some in MPR because of the ease and simplicity of it, it is also very strong when drenched in wood glue, however the strength is only equal to the bond of the glue itself, and i recommend gorilla wood glue for this
Loc Style Mount: I have no info on this one yet
Centering ring Cord Mount: This is The standard method in apogee kits, cut a small notch in the centering ring that centers the Motor Mount to the Body Tube and slip the shock cord thru the notch and tie.
Pros: Very Strong
Cons, Can only be used with kevlar shock cords because of the proximity to the motor
Epoxy Clay Mount: This Is the simplest method simply take a glob of the epoxy clay and stick the shock cord in the middle of the glob
Pros: Strong As the epoxy itself
Main Con Is Weight
Hope this helps!