I am shooting a pse longbow 50@28" 68" long. I am drawing 28.5"-29". I am shooting Beman ics 500 hunters full length with alloy inserts and 3 4inch rh feathers. I started off with 100 grain tips and when I shot a bare shaft with 100 I completely missed the whole target left at 20 yards. Shot 3 times to make sure it wasn't me and got the same result. Went up yo 125 grains, shot a good 3 shot group and hit pretty close to the group with the bare shaft with the 125. Does this mean I'm good on spine or should I try to find some 150's to see what happens? Also, would 125 be a good starting point for broad heads? Don't mind trying out field tips but broad heads get expensive real quick. Thanks in advance.