Hey guys. I need some advice on tuning arrows for a bow. I have a 68 Kodiak magnum, 41# at 28". I draw around 28.5-29" and shoot 3 under. I initially started with 31" gamegetter 500s and 125gr point. The results seemed inconsistent. Then I got some 30.5" black eagle vintage 600s with 150gr points. These seemed to group better but I still wasn't seeing perfect arrow flight. Out of curiosity I put a 250 point on an unfletched, 29" v force gamer and got a dead straight bareshaft at 10yds. Where do I go from here? Does 400 spine sound right for 42-43 lbs? I'd like to avoid 200+ heads if possible. Also, no matter what I tried I could not tune out a nock high with the v force. The lowest I could get it was 2" or so high and the nock point seemed to be slightly below level. Any advice at this point would be much appreciated. Thanks!

The 600s are probably closest to correct.  Have you tried the 3Rivers spine calculator?

Yea, when I put in the specs for the 600s I get 5.3 points weak in arrow spine. I always seem to be a bit nock left with the fletched 600s so its always made me wonder if I'm not shooting the best arrow set up.

Bama, it sounds to me like you are doing exactly what tuning is all about--- trying different spine/point weight/ length combinations to find out what the bow likes best.
I have learned to se a goal for gpp  prior to tuning so i can aim for a tuned arrow set up in that range.  For example you noted that you don't want 200+ grs up front and that's what it takes to weaken the 400 spine arrow enough for your bow, so you may want to rule that combo out and focus on the 600 spines which work well for many shooting bows in your weight range.
Take it slow--- tuning when you're tired or your form is off doesn't yeild reliable results.  Sometimes it takes me days to cut another quarter inch off an arrow.  I believe you're headed in the right direction and that your arrows will be too.

Quote from: Bamaguy2522 on December 08, 2020, 09:09:58 PM
Yea, when I put in the specs for the 600s I get 5.3 points weak in arrow spine. I always seem to be a bit nock left with the fletched 600s so its always made me wonder if I'm not shooting the best arrow set up.

Did you try it trimming 1/8th or 1/4" of arrow length?

I actually don't have a way to trim them. I've been hoping to find a combination that works with what I have. I've gotten the 600s with 125gr to group well at this point. They just group 6 inches right. May be a form problem at this point. Gonna wait and see.

I should add that group 6 inches right is at 20-25 ya which is as far as I'd ever want to shoot at a deer.

Build your strike plate out a tad, that will move the group to the left.

If the strike plate is leather, slide a toothpick down behind it.

Roy, would that not weaken the arrow and result in a further right grouping?

I shoot 41@28 and draw 28 and the arrows that tune the best for me are CE 75's with 175 up front 30 inches long. Great flight with a bare shaft.  600-700 spine might be what you need. 

Quote from: Bamaguy2522 on December 09, 2020, 08:35:25 PM
I actually don't have a way to trim them. I've been hoping to find a combination that works with what I have. I've gotten the 600s with 125gr to group well at this point. They just group 6 inches right. May be a form problem at this point. Gonna wait and see.

I used one of these to cut arrows for 3 years until I found a great price on an Apple arrow saw.

I would stay with those 600s that's what I shoot out of my 41# Browning.  Get an arrow saw but take them down 1/4" at a time .

QuoteRoy, would that not weaken the arrow and result in a further right grouping?

Not really, should move your group to the left, can't hurt to try.

Have you played around with raising or lowering the brace height?

I believe lowering the brace makes the arrow act stiffer.

600 sounds good to me,and if you've got them flying good stick with them. I always forget which way the shelf cut is weakens or stiffens. My bows around that weight fly good with 600 spine.

I've been doing sort of what woodchucker is talking about. I go out in the morning and have been doing good with the first arrow going where I want. That's what you have to be worried about.

Chris, sent you a PM.

Ok, I stripped the fletching off one of the 600s and got down to a 100gr point and was still showing 1-2 inches nock left. I'm assuming my next step is to trim them down. I could also go to the 31" 2016 gamegetters I have as well but I dont know if thats too big of a jump in spine. I have to drive to a nearby town to have them trimmed so I want to get it as close to possible. How much should I have taken off to stay in the 150gr point weight? Thanks for all the help guys!

1968 Kodiak Magnum 41 lbs.  1916 alum. 30 1/2 " long  125gr. head     462 gr. total  28 1/2 draw
bare shaft fly perfect for me

I mostly shoot wood but also carbon for stumps and hogs. I've tried the bare shaft deal never really got perfect flight but pretty good, and with feathers added no problems. I've recently been reading some info on nock tunning and about the stiff side on carbons. I tried the water floating deal and marked the heavy side on some bare shafts. I had to turn the nocks 1/8" past the line I marked but I have never seen an actual absolute straight flight straight into target bare shaft. At 10 -15 yards all you could see was the back of nock in target. All that from turning the nock starting with the stiff side toward the riser. The fletched shafts shot well but just to see I flipped them 180 from the normal position and all the shafts hit the same spot. I know a lot of this is old news to some but I'm not a carbon arrow guru and it was surprising to me. I've just shot with random nock location determined by fletch clearance. Maybe starting with tuned nocks will make a difference.

Hey guys. I think I have it figured out. I moved my silencers some and started at 7.5 brace height and kept adding 3-4 twists until I went from a weak shaft to a slightly stiff bare shaft. I ran out of daylight and didn't want to keep shooting being tired but I'm pretty sure a twist or two removed should have it as close as I'll need it. Even got to keep the 150 point weight. I have some 150 Magnus stingers on the way so they should group with my field points. I'll report back when I get some more daylight. Thanks again guys, I learned a lot, I'm glad I posted!

Did the videos help?