Sounds like an arrow that means business! Must be around 560 or so...
But if you really want to know....
Best thing to do would be to get hold of a half-dozen or so (of each) field points in as many weights between 125 and 175 as you can find. Maybe even a few heavier, if you can find or assemble them. Then either buy 3 bare shafts or scrape the fletchings off of 3 of your arrows and see what amount of point weight makes fletched and bare shafts hit in the same place.
I'm just recently getting into this myself, so I know more about what to do (because guys like Frank and Gary and Ken have been helping me out) than exactly how to do it (because sooner or later you just have to pay your dues ).. But FWIW, I'd been shooting much-too-stiff arrows for about, oh, 25 years. You can cover it up with big enough fletchings, as I did, or you can just get it sorted out properly.
And JMO... This should probably be taken more as encouragement than advice but…
Don't sweat it if you think you're not a good enough shot to make this worth your while. Just get a big piece of paper (I use opened-up paper grocery sacks) and run a line down the middle. 1" blue painter's tape works nicely and so do markers, but use whatever you have on hand, as long as it's good and visible.
Then shoot at that line for a practice session, and use a marker to indicate which holes were made by bare shafts and which by arrows. Then see what pattern develops.
I did this the other day and I was - frankly - APPALLED at the width of the scatter (I don't sweat up & down, because I'm shooting the same distance over and over and I don't want to get too locked in at 50 feet).
But then I looked at the target. Hmmmm..... Almost all of the bare-shaft holes were 2"-4" to the left of the tape, and the great majority of the arrow holes were on it or a bit to the right. So as bad as the overall scatter pattern appears to be, there is at least some consolation in the fact that the bare shafts are basically hitting 5 inches to the left of the fletched. It would be cheating, of course, but if I were to cut the paper down the line and center the one group over the other... it might almost look as though I knew what I was doing..
But those are 2016s in a mix of lengths; this bow wants a 1916... and everybody needs matched arrows!
