AST's are assigned to HITRON but their job is going to be maintaining the aviation life support on the 65's. Last i heard they were standing EMT duty at the range and you must be a E5 of higher for orders there. I've only heard of 1 AST going precision marksmen, most go there wanting a break from duty, flying or are broken.
If you want to do some spec ops shit and actually do it then start looking else where. Our attrition rate is up there with SEALS, PJ, etc but we're no pipe hitters due to our job duties, nor do we think we are. If you want the best quality of life in the military and don't mind doing underwater wrestling for 24 weeks then ya might want to look into signed that annex x or whatever its called from the recruiter to try out and go AST. Google reddit rescue swimmer if ya need more info.