I dont even try to tune my bow with a new string until ive got 200 shots through it. I have never had a string that didnt stretch.
It an unexceptable amount of stretch.
My bow had a 35 7/8 axle to axle to start.
Put the zebra on the A to A was 35 15/16 close enough to start.
After 200 or so shots my A to A measured nearly 36 1/2 (36 7/16)
That is just to many twists to put into a string in my opinion so I discarded it and replaced it.