Different arrow different results ?'s

[wyobackcountry]

So I'm shooting an original z7 at about 71#'s.
For the past two years I've been shooting the gold tip 5575 (8.2 gpi) arrows with great results. This year I switched to the Easton axis infused 400's (9.0 gpi). With the Easton's I am seeing better penetration but less accuracy (groups are twice the size). Also seeing the Easton arrows fall lower (especially broadheads) than the G.T. arrows, my assumption would be the weight difference as well as a need for a nock point adjustment. I guess my question would be if my issues are weight related or spine related? Or is the extra penetration worth the lack of accuracy? Any thoughts?

 

[3blade]

whats your draw length?

 

[wyobackcountry]

27.5

 

[shooter21]

my guess is your under spined just cause the gpi are the same or close dosnt make the spine the same imop you should be shooting a 340

 

[BigPig]

Bump up to a .340. Regardless of brands you will shoot better, especially with broadheads.

 

[wyobackcountry]

I appreciate the help. I will give the 340's a try. I recently had my local "proshop" time, tune, and give me some new arrows. Since then my shooting and confidence has suffered. This weekend I'm gonna take a road trip to another shop that fellow MM members have recommended and pick up some new arrows and re-tune my bow.

 

[AdrenalineAddict]

My thoughts would be why change from the Gold Tip if it was performing satisfactorily. The 340's may not give you the accuracy you desire either. The old adage "Don't fix it if it ain't broke" comes to mind. As far as giving up accuracy for more penetration, I would say definitely not, you already have a sick amount of momentum and KE with your Gold Tips.

 

[Brandon82]

+1 Adrenaline hit it on the nose. Shooting the GTs with a 71# z7 you will be getting plenty of penetration unless you are hunting water buffalo or moose. Even on an elk you should have plenty of penetration.

Worry much more about your accuracy than KE at this point given the setup.

 

[wyobackcountry]

LAST EDITED ON Aug-08-12 AT 08:54PM (MST)[p]Brandon and adrenaline, just so you are aware I'm not fixing what isn't broken! If you read my post I said I was shooting the GT's the last two years with great results. This year I noticed my draw length felt longer, my groups were poor, and my bow was out of time. I shot all spring and summer thinking it was a form/grip issue but with the hunts coming up and no improvement in my accuracy I started thinking. I went to my local "proshop" and had him re-time it, "tune" it, and crank up the poundage (about 8 pounds), he also recommended the axis arrows and I thought that if I bought arrows from him it would save me a 3 hour round trip drive for the gold tips. But from my "proshop" experience I figured I would be better off learning how to maintain my bow myself and have been reading and learning anything I can. My biggest concern is accuracy over penetration and was kind of trying to get a feel for which arrow I should tune to my bow.
Today I went out and made a paper frame and shot through it at distances of 6 feet out to 60 feet and would like to go over my findings of the two different arrows tears at the different yardages if anyone wants to try helping me out... Big pig? Az? Others?. Thanks.

 

[BigPig]

Bring it on, I'll do my best.

In theory, given the same spine, the groups should be about the same size, just maybe different points of impact. But you are also talking about different diameters too, the Axis being smaller. This will change your nock height just a bit so it may require a minor adjustment.

Hit me up with the paper tear results and lets go from there.

Also before you get too frustrated, measure axle to axle length, brace height and tiller. Make sure those measurements are to factory specs. Then make sure your arrows are spinning perfectly. Then rule out nock pinch or nocks that are too tight or loose. If you hold your bow upside down with an arrow nocked, the arrow should stay on the string, but it you give the string a good rap with a finger, it should pop off without too much effort. Then, remove the point from the arrow and draw back. If the arrow lifts up off the rest, you are getting some pinch. A little serving wrapped inside the lower part of your string loop should help. Lastly, make sure you are not getting any vane contact. Lets rule out all this stuff before you proceed much further.

 

[wyobackcountry]

In theory, given the same spine, the groups should be about the same size, just maybe different points of impact. But you are also talking about different diameters too, the Axis being smaller. This will change your nock height just a bit so it may require a minor adjustment.

*That's kind of what I was thinking with my broadheads falling lower than field points, especially with the Axis. Would it be easier for a DIY'er with no press (yet) to adjust the nock or rest height?

Hit me up with the paper tear results and lets go from there. ?

* All shots were taken with .400 spine arrows and 100 grain field tips. ?Also the tear results are averaged off of 3-5 shot groups at each distance.
* So tear results were as follows;
(sorry I forgot my G.T. Papers at my buddies house, I will update ASAP.)
@ 6 feet, Axis- Tail 3/4" high and 1/2 " left
? ? ? ? ? ? ? ? ? ?, G.T.-Tail 1/4" high and 3/4" left
@ 10 yards, Axis-bullet holes
? ? ? ? ? ? ? ? ? ? ? ? , G.T.-
@ 15 yards, Axis-Tail 1/2" right, good up/down
? ? ? ? ? ? ? ? ? ? ? ? , G.T.-
@ 20 yards, Axis-Almost bullet holes, tail 1/8" right, good up down
? ? ? ? ? ? ? ? ? ? ? ? ? , G.T.-

Also before you get too frustrated,?

*I'm not too frustrated and actually have renewed confidence after getting some good old MM advise as well as my tear results.

measure axle to axle length, brace height and tiller. Make sure those measurements are to factory specs.?

* I will find out what I can about the measurements ASAP ( not sure on exactly how to make them or the specs.)

Then make sure your arrows are spinning perfectly.?

* ? By shooting an un-fletched arrow with a group of fletched ones.?

Then rule out nock pinch or nocks that are too tight or loose. If you hold your bow upside down with an arrow nocked, the arrow should stay on the string, but it you give the string a good rap with a finger, it should pop off without too much effort. Then, remove the point from the arrow and draw back. If the arrow lifts up off the rest, you are getting some pinch.?

* if it matters I shoot a down force rest. ?Upside down I can NOT nock an arrow loose from the string no matter what, but if I draw it back without a point it does not lift from the rest at all.?

Lastly, make sure you are not getting any vane contact.

* I don't think I'm getting any fletch contact but I did buy some aerosol foot powder and will check tomorrow.

I will follow up tomorrow with some more info.

BigPig, ?I very much appreciate your time/info/and knowledge.

Thanks!!

Russell

 

[Cahunter805]

Russ I wouldnt worry to much about paper tuning until you get your new arrows if that is the route you want to go. Goldtip are great arrows so just pick up some 7595 and you will be set.

You could also drop your poundage to around 63-65 and maybe get away with the 5575 depending on your arrow length.

Once you have your arrows of choice and poundage set you can papertune and make the minor adjustments needed. I find paper tuning to be a good start but walkback tuning to set the centershot of your rest is better IMO.

You can spin test your arrows on a spin test device or by spinning them on a flat surface like glass on the broadhead tip and watching for a wobble. What broadheads are you shooting?

Im sure BP will be able to help you more than myself as im still learning about bow tuning myself.

 

[wyobackcountry]

I sincerely appreciate everyones opinions and advise. Thank you!

Tonight I made adjustments to my rest ((both vertically and horizontally) I feel for the vertical adjustments I should have moved my nock point, but with my current limited abilities I'm happy with the end results) and kept track of every adjustment and it's affects on arrow flight. By the end of the night my arrows were penciling at 10 feet and I robin hooded two arrows, one at 20 yards and one at 30 yards. At 30 yards I shot groups of 6; 3 field points, 2 unfletched, and one broadhead. My groups at that range with the various set ups were right on par with broadhead/field points from years past at about 2-3".

I still will try a 340 spine and will further fine tune my bow, but as far as this rookie goes I've got my A game back and am considerably closer to chasing animals with the bow this fall than I was two days ago. Any other suggestions for increasing my knowledge and abilities? Any must read books?

After seeing the results of my own hands I can not wait to learn more and get some better tools to do my own bow smithing! Bye bye "proshops"!

Thanks MonsterMulians!

 

[wyobackcountry]

BigPig,

After reading your suggestions and my latest posts, is there any suggestions you could make to further help me?

I will still try and take the measurements asked as well as follow up on a few of the suggestions that I didn't/couldn't make.

 

[wyobackcountry]

Sorry but one last observation.
I believe that the guys that mentioned being under spined were spot on and here's why, the vertical adjustments were easily adjusted out with only two adjustments. The horizontal adjustment was a seperate beast, after many arrows and a dozen adjustments I was able to get the tail left tear to consistently be at approximately 1/8th inch but it's still there.

Tomorrow will tell what the affects of my tinkering will be at 40,50,+ yards.

 

[3blade]

The farther out you go, the worse the spine issues are going to be if its not right. I personally don't think a 340 spined arrow is enough. I shoot a 60 lb bow that is not a slowpoke and I have to use 340's minimum, I use 300's, because 400's are way to weak but I do have a 29" draw. Maybe pick up a couple 340s and a couple 300's and try them, then go with what works best.

 

[wyobackcountry]

I got tired and didn't want to force my shooting today so I called it good (enough).

I will be picking up some more arrows tomorrow and I will throw in a stiffer spine or 2 to see the results. As well as see what's going on at longer ranges.

 

[dingo]

Lots of good insight so far. Yoke tuning hasn't been brought up yet so here is what I do to fine tune my arrow flight. I will assume that you have factored in everything previously mentioned and your bow is timed and in sync and your center shot is on.

When you come to full draw, the limbs fully compress and the stresses reach maximum levels in the riser. The cable slide/rollers hold the cables out of the way so there is no contact with the fletching. This creates an imbalance in the forces and results in setting up bow torque. This is not the torque that can result from your grip. These internal stresses are what flex the riser and throw off the third axis. They also exert a side load on the cams and cause them to change angle through the draw cycle. . The lean at rest is different then the lean at full draw. When you release the arrow and the cams rotate, the string will actually move left -right, right-left, or neutral as the cams change angle during the shot. You need to adjust the yoke to compensate for this. Unfortunately for you, this will require a press.

You can use a draw board to check your cam lean at full draw as compared to at let off.

You can tune the yoke using a bare shaft shot from around 6 ft. Shoot into a foam block and see which way the shaft is pointing. (The target should be at shoulder height. ) Adding a twist to one side of the yoke while removing a twist from the other will change the angle of the cam. When you are done, you want the arrow to fly square into the target. This process MAY cause you to hit slightly higher or lower depending on if you shorten or lengthen the cable. You can clean up nock travel by adding or removing twists to your bowstring once the horizontal travel has been adjusted.

When your fletched shafts hit with your bare shafts your bow will be quieter, have minimal vibration, your speed will be maximized, you will shoot tighter groups, and your broad heads will hit with your field tips. Sounds like your getting close to having it dialed in.

 

[BigPig]

LAST EDITED ON Aug-10-12 AT 11:45AM (MST)[p]LAST EDITED ON Aug-10-12 AT 08:19?AM (MST)

I'll give it a shot here. From the sound of your paper tuning results you had some vertical and horizontal movement of the arrow. Sounds like it was corkscrewing through the air and depending on the distance tore the paper in odd ways. But now it sounds like some rest adjustments got most of that worked out. That is good. I definitely still think you need .340 spined arrows. Most spine charts out there are outdated for todays aggressive cams. When in doubt, go stiffer. You can almost always get a slightly stiff arrow to fly well, you pretty much never can with a weak arrow. Make sure you have some helical fletching on those vanes too!

Make sure your arrows spin true with a broadhead. Just spin them like a top with the point down on a table. You don't want any wobble. Yes, also verify you have no contact with lipstick or foot powder spray on your vanes. I also like to make sure bow measurements are to spec. Check your manufacturer's website for correct specs.

Then check for cam lean. Make sure your cam(s) are straight up and down at rest and at full draw.

Nock pinch. Again, hold your bow horizontally with an arrow nocked and pointing straight down, string facing up. Give the string a firm rap with an extended index finger. The arrow should fall off the string. You don't want it falling off when you turn the bow upside down, but you do after a good pop on the string. If you cannot get the arrow to pop off, the nock is too tight. Sometimes this happens with a new string. Nock and renock an arrow a whole bunch of times to break in the center serving. It should "wear in". If not, you either need different nocks, or can redo your center serving with a smaller diameter material.

Once you know the bow is set properly, and you know you have the right arrows and they spin true. Then you start tuning. Adjusting the rest and/or yoke tuning. Then verify by shooting through paper and/or walkback tuning and/or bareshaft tuning. Then lastly broadhead tuning. Then adjust your sight.

I strongly suggest doing things in this approximate order. Attepting to tune before you have rules out all the static stuff can only lead to you chasing your tail and getting frustrated. Tuning is much easier and effective is you rule out the basics first.

Lastly, if you are sure everything with your set up is perfect and you are still getting undesirable results, check the Indian - not the bow. Grip torque, dropping your arm, peeking, punching the trigger, pressing into or pulling away from your face on release... all these things can cause problems too.

Achieving clean arrow flight requires a multifaceted approach.

 

[3blade]

Now that I'm home, that bow will shoot a 340 spined fmj at 29" long with a 100 gr head. It will also shoot the Goldtip 7595 with 100 gr head at 29" long. If you want to shoot a 125 gr head, cut an inch off the arrow length. This will get you really close and you can make fine tuning adjustments from there.