RH shooter- arrows doing anticlockwise spiral

[gringol]

ozy,

I'm not sure increasing brace height actually "weakens" the spine.  I think it makes it easier for the arrow to get around the rise because it leaves the string sooner.  So your setup becomes less sensitive to spine...Not sure if I'm right here, just my thoughts...

Also, I wouldn't take Stu's calculator as gospel.  The proof is in the pudding and if it isn't working for you, I'd forget about it...

[Caughtandhobble]

Originally posted by xtrema312:
If I have all the right info in Stu's calculator correctly, your bows needs 77# spine and your arrows is 34#.  I always end up on the weak side of what the calculator says particularly with 400 spine carbon, but not 40# weak.  Even at 28” if you had the 100 insert and 250 point you would still be 30# under spine per calculator.

Get a 27-28” shaft if you have one and drop down point weight to something like 250 gr total point and insert.  Then see what happens and play with the point and/or inserts as needed to raise or lower the total point weight to tune.  I would usually not tell someone to go real short on arrows right off, but with what you are trying to do for a heavy arrow with EFOC, I think you can do that with a one shaft to start.  

Try a quick shim on the side plate also once you get in the ballpark if your arrow is still weak.  That can be faster than changing inserts if you don’t have a full range of point weights to get where needed and you can’t cut down your arrow any more.  That could help you also if the combination of a thin plate materials, cut well past center bow, and a skinny carbon are making for too much cut past center to give you the forgiveness you need for finger shooting. I have not shot a bow cut that far past center and those diameter carbons to know for sure on that, but I do know of a couple people who have built out to get those shafts to shoot well for them.

There are a lot of variable, but I am going to guess that with that shaft and a 250 gr. head, you will end up with a 27-27.5” shaft, 50 gr. Insert, and maybe a little playing with brace and side plate thickness to get it. Maybe even a standard insert, but I have a feeling you want brass so I figured at least the 50 gr.

Once you get something set up within about 10-15# spine of what the calculator says, then keep track of what each change does to figure out what is going on.  I try to let my nock point be a little high to keep shelf issue out of things until I get my left to right close.  In addition, I have a hard time getting level flight out of a bare shaft with HFOC – EFOC.  I just can’t do it so I plan to have a bare shaft always fly a little nock high and left. (Right handed)

X2
That's what I was thinking... It works very well for me.  

[ozy clint]

changing point weight is not an option. i have to have 350gr total upfront. it suits the many BH's i have.

i'll try a short shat agian and see.

[Jeff Strubberg]

The few times I've had arrows corkscrewing, I found I had a nock point issue (usually too high) exaggerating a spine problem.