Are you using 2 nocksets on the string such that the arrow nock fits between them? If not, try it and see what happens.

 

Yes, using double nock set. Tied nockset.

 

How "high" is high?

Tiller for split vs 3 under will make a difference, but unless the bow is seriously messed up should not render the bow "unshootable". The difference should be able to be handled with tuning.

For purposes of clarification, how do you measure nock point (NP) ?

I always consider ZERO NP to be that line that is directly on and dead level with the shelf/rest and that intersects the string at 90 degrees. So with that as 0", a NP that gives an arrow that is dead level and intersects the string at 90 degrees would yield a NP measurement that is greater than zero by the thickness of the nock, top to bottom.

Not everybody sees it this way, there seems to be no "standard" method of measurement for NP. Some folks see it as a dead level arrow is at ZERO NP even though the NP itself is higher than dead level.

Measuring the way I do, and shooting 3 under, I regularly run a NP in the neighborhood of 9/16" Some folks don't get decent results until they hit 5/8" and I have heard a few cases of running as high as 3/4"

I suspect that these higher NP values may be related to certain qualities of the individual shooter's grip and/or release.

 

I'm measuring the nock point same as you are doing. Shelf is 0" I shoot my recurves at about 1/2"-5/8" depending on the bow and what diameter arrow I am shooting and haven't had this much issue with setting a nock height ever.
I don't think the bow is damaged in any way, certainly isn't visible. Bow is quiet without string silencers. No riser contact with the arrow that I can tell or hear. I'll try going up with the nock but have never had to go up past 5/8 with any bow. Every bow is different. I think most of my recurves are set at 9/16" also.
I am just working my way up to this draw weight and my form certainly could be a factor but I thought not as the lateral movement of the arrow is so good, even bare shaft. I certainly wouldn't rule out ME to be the limiting factor. LOL

My recurves are a Black Wolf riser and SF Forged+ riser using ILF limbs, medium and long to make up bows ranging from 60" to 70" in weights from ~28# to 42# at my draw length. The longbow is quite a bit more weight than any of my recurves.

 

I had the same issue. I was bare shaft tuning my A&H with GT Hunter (camo) XT 35/55 shafts. As near as I can tell, the the camo xt hunter shafts are .400 spine in camo and .500 in black shafts. Anyway, my arrows were showing weak and nock high until I cut them down to 28". I pull 27.5". Once I got them grouping with fletched arrow, down the middle, the bare shafts were still showing nock high slightly. My nock was 1/2", measured at the bottom of the shelf, plus center of the nock. I was as high as I could go because I was at the top of my bow square. I just went with it since my arrows were grouping with bare shafts & fletched shafts.

 

For a bow tillered for split finger but shot three under, a nocking point that is 3/4"-7/8" from the bottom of the top nock point to a line defined as perpendicular to the string and flush with the shelf is not out of the ordinary, at least in my experience.

It doesn't take much contact to give the back of the arrow a bit of a bump up, which can seem like your nocking point is too high. I don't know if that's what's happening for you but it's something to think about.

My question, how do your fletched arrows fly? I've found that a setup where bare shafts group slightly lower than fletched at 25-30 yards is not a bad way to go. By slightly lower I mean a few inches. This shouldn't mess up your arrow flight with fletched arrows and it's probably not so low that broadhead flight is affected either.

 

You might be on to something there. The bare shafts really flip up off the bow like there's contact. I've gone up to around 3/4" and they're still flipping. Fletched fly great at about 9/16 to 5/8". The bare impact pretty well with the fletched with field points. I haven't tried the bare out that far. Furthest I've tried is about 20 yards. I'll try again tomorrow. I really appreciate the help.

 

I shoot 3 under and all of my nock points are in the 7/8" range. Some are a little higher. I have found that even changing string material will effect where the nock point has to be for proper flight.