I was shooting a bare shaft with a 100 grain FP. The arrow flew good for about 18YDS, and then took a total 90 degree turn to the left. Im a right handed shooter. Whats going on here.
Thanks.

Try heavier tip weight.

nock right indicates a stiff shaft (left turn). try more point weight or a longer or a shaft with a weaker spine. Try to hold the bow as vertical as possible when fine tuning with bare shafts.

The thing about a bare shaft is that it doesn't really tell you much unless you make a "good" shot.

An imperfect release, a collapse or torqueing of the string or bow can make a bare shaft do all sorts of crazy things.

unless you shoot one arrow and call it as gospel that doesn't hold true MFG.  Plain and simple you gotta shoot more than few arrows to get a real reading..the more you shoot obviously the better your outcomes going to be.   Sure we make bad shots and you'll surely see it with a bareshaft...I think most shoot enough to get an idea of what reading is correct in the end, even though for whatever reason people don't believe it.  

Breaz,

The fact you're shooting that far with that poorly of a flying shaft would warrant starting out a little closer.  If you're shooting carbons watch for cracked shafts hitting sideways..or bent aluminums.  Woodies just flat out snap, doug fir will explode LOL!.

I don't really disagree but if you  tend to make the same sort of mistake, the bare shafts will tend to fly the same way. You can tune for it to some extent, and I guess you should, but you'll be out of "tune" once you stop making that mistake.

I recently had to do some tuning and I don't know if I shot too much and got tired or if I was just being sloppy but bare shafts were showing real stiff...pretty consistently and I knew they shouldn't have been that far off.

A little cleaning up of my shooting and they fly great and group where they should. I tuned me instead of the bow/arrow. LOL

Or, add 5.5" fletching and watch that arrow fly nice and straight.
ChuckC

until you put a broad head on the arrow and then it's wonky again.

I don't think it matters one lick if you've got poor form you've got poor form.  If you tune with any method and make a change to form.  You're likely going to end up retuning regardless of how you get there if the form change was changed enough to warrant it.  Doesn't matter if you group tested bare shafted paper tuned or hucked it down range by hand lol

It's ok to dislike bare shafting.  It's another tool In the bag of tricks you can choose or choose not to use.  None are wrong if it gets you were you need to go.

Don't get me wrong...I not only use bare shafts to tune but I also shoot some bare shafts as part of my regular practice.

Stiff does not show well for the first 10-15 yds the arrow has too much forward momentum at 20 yds it has slowed enough for the indications to show up. at 30 yds even more. I can shoot 30 in my yard so that's my limit.  

Made a error when typing my initial post. The tip is 125 grain, not that it matters much.
I think my form is pretty good... not great but I do make a conscience effort to do things right when I shoot trad bows. Admittedly I am pretty new to trad, and I am sure their is room for improvement, I know theirs room for improvement.
Think im going to get some longer arrows with the same tips, and cut them down as I go along. My draw is 27 inches, and the arrows I shoot are the same. Bow is 48 at my draw, arrows are carbon.

breazyyears, there isn't a lot of information in that initial post. You are drawing 27" and your arrows are also 27"? That seems a bit short unless your arrows are weak and you have to cut them back that far. In your case, with the arrows flying stiff, I would suggest you start with full length arrows. You said they were carbon, but that covers everything from floppy 800 spine shafts up to "stiff as a board shafts". I can shoot 500 spine arrows, 30" long with 175 gr field points nicely out of my 46 - 48# bows with a 28" draw. If I want a faster arrow, a GT 1535 cut 29" with 125 gr up front flies nicely.

What shafts are you shooting?

The laws of physics simply do would not let an arrow make a 90 degree turn at any point in its flight...we need a more accurate description of what is happening and we will still not likely be able to help...if you narrow down what part of Canada you live in I can likely direct you to someone who can help...not sure why Canadians on here think that is a good way to describe where we are from...not a lot of members say they are from the United States

DDave