I'm getting myself dialed in for this fall (can't think about much else) and I am having an issue bare-shafting my new arrows.
I am drawing 29.25ish inches on a 60@28 Bear Montana. I recently purchased a set of Easton Gamegetter 300s (aluminum) that I have outfitted with a 100 grain brass insert and 200 grain point. Bare-shaft tuning has slowly brought me all the way down to 29.75 inches (half an inch over my draw) and they are still showing weak. Out of curiosity I've run points from 125-200 grains through the arrows to see if that would fix the problem and they all continue to show weak. For what its worth, the 3 Rivers Spine Calculator has my setup working nicely so I don't think that I am too far off the mark. Fletched shafts fly pretty well to the naked eye.
I am going to try:
1) Further decreasing the brace height though I am getting close to the lower end of the recommended 7.5-8.5 inches.
2) Paper tuning to see how they are coming off the bow.
3) Learn to be a better shooter so that form issues don't influence my read.
4) Not worrying about it, fletched arrows are hitting where I am looking - make sure my broadheads are sharp and pray for September to come quickly.
Any thoughts y'all might have would be appreciated.
A 300 aluminum is like a 2219 or 2317? I would think that it would possibly be too stiff and giving you a false weak reading (hitting off the riser). Just a thought.
http://www.acsbows.com/bowsetup.html
Go to knowledge base then bow tuning.
And this video.
https://www.youtube.com/watch?v=BSJ6-HjPMTM&t=18s
Hermon has a point, there may be an issue with overspine, but i dont shoot ali, so cant comment on what you have there,
what i do see though is that by increasing your point weight, you are only going to weaken the spine, reducing point weight will stiffen the dynamic spine.
Is the nocking point in the right spot?
Is it too thick/too thin?
Is the string well made?
Are you spune testing with field pounts or broadheads? (You should use field points)
Just trying to brainstorm. If the bare shafts don't flight straight there must be a reason. Don't give up on it, it might take time, but you will be a more knowledgeable archer after you solve this issue. Troubleshooting is one of the greatest sources of experience ;)
https://www.youtube.com/watch?v=IGOPiriLbcM
Also, in my limited experience, changing point weight might not be as sensitive of a test as trying a different spine. Get a test set from 3rivers, try 360 and 400 and see how it goes.
Sorry for the typos, phones keys are too small for my fingers :P
Quote from: Hermon on August 06, 2018, 11:16:20 AM
A 300 aluminum is like a 2219 or 2317? I would think that it would possibly be too stiff and giving you a false weak reading (hitting off the riser). Just a thought.
This
after bareshafting, i always like to group tune with bareshafts, fletched field points and fletched broadheads
i agree with Max, a test kit is a good option!
Sorry for the multiple posts, if you're using aluminum, 340 might also work. Try a few spines and see how it goes
Quote from: fujimo on August 06, 2018, 12:59:55 PM
i agree with Max, a test kit is a good option!
;)
Thanks everyone for your suggestions. I went with the 300s based off of spine charts and the Spine Calculator, taking into consideration that I am shooting 300 grains up front. However, the false read of a stiff spine bouncing off the rest sounds very plausible.
The problem is, I started with a full length shaft and cut away a fair amount of the nock left which, to me, means that it started weak and I stiffened the spine by shortening the arrow. Tonight I am going to shoot a full length shaft again and confirm that it is, in fact, worse than the arrow I am working with now. If it all looks the same then you guys are probably right and it is too stiff to start with.
Arrows are like shoes. You might expect size 10 would fit you, but in the end you need to try and choose the ones that actually fit you ;)
I'm thinking stiff. I have some 55 and 60 and making 2117 and 2018 work.
Alexander Traditional, how much weight were you shooting up front for those?
Hey drunk weasel :biglaugh: I went out and looked at the 2018 and they had a 175 grain on the front. I didn't think that could be right,so I strung up a 55 lbs bow. I shot them and got good flight,but those arrows are long at 33"
I shot some of my 2117 out of the same bow and they had 250 up front. They flew ok. I may have bee shooting them out of the 60lbs. They are a stiffer spine than 2018,and they are 29".
I like the 2018 better. You could start around 175 and keep going heavier.
Heh heh, maybe that's why my arrows won't fly right! And thanks for the info!
whiskeyweasel....Is the 60@28 accurate?
This is the heaviest draw wt. that the Montana is built to.
I've never had it on a scale but it is rated at 60#.
I also shot a full length arrow again tonight and it definitely flew worse (weaker) than the cut shaft. I think I might actually be pretty close, maybe tweaking the nocking point and building out the rest a touch. Thank you all for your help!
Raising or lowering your brace height may help also.
Try it both ways.
Put a flipper rest on it and call it a day. I enjoy shooting off the shelf but when tuning gets to be a pita the flipper is getting slapped on. Convinced I could shoot rebar of a flipper with no probs.
I understand you wanting to get everything perfect, the game we hunt deserves as much. In your original post in number 4 you said fletched arrows were hitting where you were looking. Put the broadheads on them that you want to hunt with and shoot them from 10 yards if they are still hitting where you are looking and going into the target straight move to 20 if you are still hitting where you are looking you are done go sharpen your broadheads. We don't hunt with bareshafts there is a reason we put fletchings on them. If fletching want correct the problem the spine is way off. I hope this post does not come off as being smart I don't mean it to be. Good hunting Jimmy
On the surface they seem overspined.
I'm using .340 Eastons with 2 inches of alloy footing, 100gr. insert, 125gr. broadhead adapter, 200gr. broadhead out of a 68lb longbow and they're full-length! I know every situation is different but they're tuned bloody well.
I think you need a 340 spine.