Math 2 Subject Test

If I want to go to one of these schools, how badly would a high 600 math 2 score affect me, assuming high scores on all other tests (34-35 ACT, 770 on Bio M)?

Princeton
Amherst
Dartmouth
UCLA
UC Berkeley

I’ve heard it only counts for like 5% of the decision but idk where people get that number from, so please help. Thanks!

Subject test scores aren’t the most important part of your application, but a 600 is significantly lower than the usual ballpark of top schools. A 600 is 23rd percentile - yikes!
http://www.collegeboard.com/prod_downloads/about/news_info/cbsenior/yr2005/16_subj_test_percentile_ranks_0506.pdf
I would recommend retaking or taking another test.