Arrow spine not making sense, to me

[ksnow]

Okay guys, I've rattled my brain enough, time to rattle yours.
I am shooting in an elm bow, 45# at 26 inches, basic pyramid, 1 3/8 wide at the arrow pass.  String is centered in the handle. I shoot right handed, split finger. All this shooting is at ten yards.
I have a set of 40/45 pound POC arrows with 125 grain field tips, 29 1/2 inches long that shoot dead center. These have three 5 inch fletches (LW).
I have a set of 45/50 pound POC arrows with 125 grain field tips, 28 inches long, that hit 5 inches out, high and right. These have four 4 inch fletches (LW).
I can't understand why the heavier spined arrows (which are shorter) would hit to the right of center. I thought it was my form or release, but I've switched between the sets of arrows numerous times and the general pattern is too obvious.
I was thinking to try 145 grain points on the heavier arrows, to "weaken" the spine, but everything I read and have heard says that heavy spine should hit left. Does the 4 fletch act that much different than a three fletch?
Any ideas?
Thanks.

Kyle

[willie]

kyle,

when you write 40/45  or 45/50 it reads like what it says on the box.

have you actually measured these arrows recently?

[ksnow]

I don't own a spine tester, so I have not checked them.
The ones labelled 40/45 are definitely weaker spined than than the ones labelled 45/50.

Kyle

[osage outlaw]

I'm no expert on arrow spine but they are 5 lbs stiffer, plus 1.5" shorter so that's more like 12 lbs stiffer than the good arrows if you go by the 5 lbs stiffer for every inch cut off rule.  Try some heavier points on them and see what happens. 

[ksnow]

Osage, that's what I was thinking, they are quite a bit stiffer, why then would they hit to the right, when everything I read says left? It just doesn't make sense to me.  I think I'll swap out the 125's for 145's and see what  happens. 
Or go nuts and try some 75 pound arrows I have, that should be interesting

Kyle

[willie]

do both set fly fairly straight? have you tried  shooting at just a few yards to look for nock left/right?

[ksnow]

Well, I can't explain it, but I put 145s on and they were closer. Replaced those with 160 grains and they fly just like the others. So, the stiffer arrows were going right. To take it further, I grabbed a couple 75 pound spine arrows, with 125 heads and just about missed the entire target, to the right. So, it's solved, I guess. Thanks guys.

[BowEd]

ksnow...You've got it right now.Arrow making can be confusing in the beginning.Proper consistent anchor while shooting does the trick to evaluate the shafts,and it seems you are doing that.You're on the right track now.Have fun!!This pic I hope is readable.Not a very good camera....lol.It is from the TBB 3 book on page 230.

[Knoll]

Ya have me buffaloed, Kyle! Hope someone chimes in with explanation.

[ksnow]

Looked at the bible, Vol 3. It says stiff arrows impact to the right, which is what I was seeing. Not sure why everything else I read is opposite.

[willie]

might have something to do with the arrow pass width/centershot

http://www.primitivearcher.com/smf/index.php?topic=15175.0

[loon]

I'm curious, at what angle do they hit the target? Tail right?
This stuff is confusing

[TSA]

in my experience,  bareshaft and fletched arrows will tell the same story just differently.

where a bareshaft will say throw the nock left( so kinda point right!), that will indicate a weak shaft, whereas the same weak, but fletched shafts will impact to the left, this is due to the stabilisation factor of the fletches.
so if your FLETCHED shafts, as a grouping are impacting to the right, yes that is stiff, if you stripped the feathers off, that bare shaft would show nock right, and point left!
 
however bareshafting can really expose errors in your shooting form, and so, in turn, tell lies!
make sure your form is good, take your time, shoot slowly- dont fatigue- even use a clicker just for the tuning- focus on your release. ( or look up Rick Welch and his method of shooting- its a fool proof way of ensuring the same drawlength and same back tension ever time!!)

-dont cant the bow
-shoot groupings
-start close- otherwise you will break shafts!!!

i like to get in the ball park with the bareshafts, thereafter i follow Adcocks advice,
the real ticket is "group tuning" shoot a group of bareshafts and a group of fletched shafts, and get the final points of impact the same- use groups, 3 or 4 shafts!
http://www.acsbows.com/sitebuildercontent/sitebuilderfiles/tuninglongbowsandrecurves.pdf

last tip. when bareshafting- i finish up just a tad weak- as the fletching will stiffen the shaft a wee bit.

[Knoll]

ahaaaaa! Thanks.

[ksnow]

That makes perfect sense with what I was seeing.  Thank you very much for that explanation.  I was thinking there was some confusion over bare vs. fletched shafts, point left and right versus nock left and right.

Group is what did it for me.  I shot 3 of each arrow and looked to see what the group trend was.  At the end, all 6 arrows were in a single mixed group.

Kyle