2footroper

Can anyone give me a heads up on spine stifness? I'm shooting a Reflex Super Slam bow set at 70#, 30" draw, Qad ultra rest, 27 3/4" arrow length. I am drilling my target out to 50 yards. All that said, I have noticed when I shoot the Easton Epic 400 arrows, I am getting avery smallamount of cork screwing in flight!!! I hit dead center at all distaces but this bothers me. I also have some older Carbon Impact 55/70 arrows that I refletched and when I shoot them the problem is solved. I cant find any info on these arrows to tell me if they are stiffer or softer spine. I am shooting the same 1oo gr. field tips and the same fletch on both arrows.
Ibelieve the bow is tuned properly and I have had it to 2 different pro shops and paper tuned and checked. They both said it was perfect. Should I go to a stiffer spine with the Eastons? Maybe I'm too picky about this because I am shooting better than I ever have before but this just bugs me. Any suggestions???????[:@]

mobow

Did you yourself paper tune it, or did someone do it for you? You have to tune your own bow, because your release style and form are unique to you. It's just like sighting in a rifle. Don't ever trust one sighted in by someone else, always do it yourself. I guarantee you it's a tuning issue. I checked Carbon Impacts website, and without knowing exactly what arrow you are shooting, I can't relay the spine information. I would suspect they are just a touch stiffer than 400, probably like a 360, but I am merely guessing at that. Your 400's should be right on given the 27 3/4" length. Any longer and you'll need 340's, so it's possible you are just a tick little bit underspined.

At any rate, head back to the shop and paper tune the bow yourself. Get help w/ the adjustments and such if you need it, but you be the one doing the shooting.

Paul L Mohr

According to the ONTarget software with that set up you are very weak, even a 300 would be slightly weak, but barely in the green.

What is your finnished arrow weight and speed if you know it, then I can calibrate the software to your exact set up.

I checked some carbon impacts, and the 7500 come up about the same as the epic 300's. They do not list carbon impact as a 55/75 designation, and neither where any of the carbon impacts I owned. Are you sure they are carbon impact arrows?

Either way according to my software you need somewhere between a .300 and .320 spine. The easton C2 Obsession, and C2 HD green spine better.

You can get weak arrows to paper tune, I have done it. I got 1816's to shoot bullet holes with my Mighty might set at 26 inches and 60 lbs. That is waaaay weak. Yet another reason I hold no stock in paper tuning.

Paul

2footroper

Hey Guys,
Thanks for your help. I personally set this bow up myself and as part of the setup I papered it and it shot bullet holes. The reason I took it to two pro shops is I thought I screwed something up. I wanted to see if they came up with something I missed. Mind you this cork screwing is very minute. As I said, I'm very accurate with this bow. I don't shoot more than 2 arrows at the same spot as I will hit them. I don't have a scale so I can't give you a weight on my arrows. I rechecked the arrows and they are definatly Carbon Impact 55/70 Buck Hunters. These are older arrows that I never used before. I realy think this is a spine issue. I just don't know if it is worth throwing away the Eastons I have & getting some 340's or300's. I do have a scale @ work that I might be able to use. If so I will weigh them tomorrow and let you know the difference.

BGfisher

There's no doubt in my mind it's a spine issue. Why don't you try dropping the weight on the bow about 5# and see if it improves the flight?

Rob/PA Bowyer

Let me bring this up to you, many times when people think they are seeing a wobble/corkscrew in their arrow it's nothing more than seeing the off color fletch rotating/spinning....could this be the case. Have someone stand just off to the side and they'll see things more clearly.

2footroper

Hey guys. Thanks for all the help. Maybe I'm just being a bit anal about this. I am accurate with my shots.
Paul,
Here are my total arrow weights with the broad heads.
The Carbon Impacts are 363 gr.
The Eastons are 403 gr.
Thanks again for all of your help.

Paul L Mohr

Well I come up with the epics weighing 375 grns if I let the program figure it up, but I figured it at the weight you gave me. I assume the speed you have listed in your sig is with the 400 grn arrows?

If that is the case they still show up weak. The C2 epic 300's spine perfect according my software with that length, tip weight and fletching. It shows them weighing 401 grns though, so if your arrows now weigh 403 grns figure on the 300's weighing around 425 or so. It would drop your speed down to about 280 fps or so. Then again maybe not if your arrows are currently under spined you may be losing speed from it. The proper spined arrow may be more effecient and come out of your bow better possibly getting you some more speed. So you may not lose any, however the slight amount you will lose will not be noticable.

You are currently shooting a mechanical broad head which is pretty forgiving as far as flight goes. I bet if you switched to a fixed blade head you would have some problems with those arrows flying well. Also, while mechanicals are forgiving of flight problems and spine as far as impact points go, they do not perform well with an out of tune bow or weak arrows.

Not that they won't work, you have plenty of power to use them, but they could work better with a properly spined arrow and a well tuned bow. If you had a light set up like mine you would be able to tell the difference in performance on game very easily. It would be the difference between a pass thru and a possibly wounded animal.

Good luck and let us know what you find.

Paul

2footroper

Thanks for all the info.
Paul,
I think I'll try the 300's. A man can't have too many arrows. A little more weight won't hurt. Even if I loose a little speed, I'll gain in penitration. I feel thats a good trade off. The bow is dead on out to 60 yds but where I hunt here the woods are pretty thick. I don't think I would be comfortable with a shot beyond 40yds. anyway. Thanks again for all your help.