The PST 4-16 has 21 mils of adjustment. Based on a 0 moa base, you "should" be zeroed around the center of the adjustment range. That "should" leave you with 10.5 mils adjustment.
1 mil = 3.6 moa
3.6 moa x 10.5 = 37.8 moa
How many MOA to reach a grand for your rifle?
The scope will be sufficient if you buy a 20moa base.
Now, if you are going mil/mil ffp, do exactly as I was told. STOP THINKING IN MOA.
Does that help?