I just put on 8125 for string and 452x for cables, how many times do I need to shoot before I start sighting it in?

I like to get around 100 shots or more into the bow before I begin tuning. Of course that is with premium strings and cables. My material of choice is 450+ or 452.

It will depend on how the string was made. Most factory strings need quite a few shots to get the initial creep out of the string - up to a couple hundred or more. Any string that is pre-stretched will probably be ready to go within 10-50 shots.

no matter what string maker i've used, made them myself, or even WC, i've had my best results shooting 30-40 times then hanging the bow up overnight, shooting a couple shots, then putting my peep in. the pro-shooters i hang with on wed nights pretty much all shoot WC strings and wouldn't dream of competing or fooling with anything until 200 shots.

If they were prestreched (which they should) before you put them on 20 to 30 shots should do it. I like to shoot even more than that to insure they have settled.

ditto that, thats my choice as well. Very little stretch.

Is the 8125 better than that mathews zebra string? Also you mentioned that 450+ and 452 were priemium strings, 8125 is not? So 450+ is better than 8125 for strings? I'm confused, don't know much about strings and what is better than the other. What are the advantages to have 450+ rather than 8125?

8125 is Dyneema which is a good string with low creep 450+ and 452x is a blend of dyneema and vectran which is suppose to be no creep. Its a give or take, do you want speed or no creep. Vectran slows the string just a little and dyneema is considered a faster string. I like 8125 and dynaflight 97 strings. That is all I used up until this year. I switched over to 450 plus and 452x and like it. Time might tell me different. As of now, I love 450 452 because the settled very well and seem to shoot well.

Oh, and zebra is a good string, it is made with dynaflight 97 and is special because of the double twist that keeps the string from moving when you draw. I used Zebras for years and like them.