I got some new CX Predator II shafts from Big Jim recently and my intent was to use Stu's Calculator and build an arrow as closely as possible to the numbers the calculator gave me. Here are my results with pics of the fletched arrow and the bare shaft arrow from a distance of 20 feet. I would like some advice on if this looks pretty close to what I should expect.
Same point of aim and the bare shaft hit nearly the same point of impact except about 1.5" lower. The fletched arrow appears to be coming out of the bow like a dart.
Bow Dynamic Spine number is 45.0 pounds
Arrow Dynamic number is 46.4 pounds.
Arrow Outputs- 465gr. (475gr. Acutal Wt.)-10.3 GPP-FOC 19.4-Speed 176.5 fps (Stu's Calculator not Actual)-Energy 32.1 ft/lbs.
29.750" Arrow BOP - 198gr. total up front with 60gr. weight added behind insert.
Bow Bear Grizzly (older style) 48# @28" my actual draw around 27-27.5"
Both pics are the same, just different angles. The bare shaft appears to be leaning downward at the nock end, but it's really not. It's pretty much straight in the target with the nock end pointing to the right slightly. The point that it enters the target is what I wanted to show. It hits nearly the same spot but about 1.5" directly below the fletched arrrow.
Is this what I'm looking for?
Thanks.
(http://i714.photobucket.com/albums/ww146/mohunter68/BareShaftTuning002.jpg)
(http://i714.photobucket.com/albums/ww146/mohunter68/BareShaftTuning001.jpg)
How many shots did you take? The bare shaft hitting low could have been a bad release or maybe you dropped your bow trying to peek. Either way I would say your good to go.
It looks like it might be a little tail right,now shoot it at 10,15 and 20 yards,
semo that looks pretty good to me. ive always been told the bare shaft should hit a little low and slightly to the right from fletched shaft. then adding fletch stiffin arrow slightly.but i think your right on.
Looking pretty darn good. I usually shoot about 6 too 8 groups to verify. Good luck.
Does your fletched shaft hit where your looking with good arrow flight if so it sounds good to me.
I shot this same scenerio several times and got the same exact results every time. I only made up the 2 arrows just in case I needed to change something.
I'll take it outside when it warms up a bit and shoot it from about 10 yards and see what I got.
I had also read one time that the bare shaft should hit a little lower than the fletched shaft, but couldn't remember exactly. So I thought I'd ask the masses for their experience.
Thanks for the replies.
QuoteOriginally posted by GRINCH:
Does your fletched shaft hit where your looking with good arrow flight if so it sounds good to me.
Yep it sure does and it looks like it's coming out as straight as a dart. I'm fairly impressed with the result using Stu's calculator so far. Being able to just build a completed arrow from scratch using nothing but the calculator specs, then hit this close in actual shooting is pretty spot on. This is the first time I've used the calculator.
One more thing, the 10gr. difference in what the calculator showed for a finished arrow and my actual arrow weight is probably the white arrow wrap that I forgot to put into the calculator. I've never weighed an arrow wrap before, but it's probably 6-8gr. or so?
I think an inch and a half low at 20 is significant. All things being equal this would put you 4-5 inches low at 20 yards. I believe the bare shaft tuning process authored by O. L. Adcock would suggest lowering your nocking point. Give it a try and see if the bare and fletched shafts shoot to the same point of impact.
A couple of points. Twenty feet should have the arrow out of paradox, so now try at a greater distance. To do this I take a golf ball and glue a tee to it. I place it in the ground in front of the target so that when I put the point of the arrow on the ball and release I hit the center of the target. Now make a couple of shots and see how often you get the same results. YOu can feel when you made two shots with good form. Record the results and decide what you think you should do and quit.
Go back the next day and try to get the same results two days in a row. Then make a change.
Next take a big broad head like a 160 Snuffer and a field pt of the same weight and compare how these two impact the target. Shoot the Snuffer first so you don't damage the FP.
I try to tune with the 160 gr in mind. 160 plus an adaptor of 35, 75, 100, 125 grains.
Bowmania
One other thing. I never fletch that bare shaft. I do all my blind bailing with it. A good form checker.
Bowmania
I've been playing around with the nocking point a little bit because the shafts do impact a bit low at 15-20 yards. I know the arrows are hitting lower than my old arrows, but these new ones are a bit heavier than my old ones so I'm sure that's part of the difference. I can deal with that as long as I'm getting good arrow flight cause with practice with my new arrows I will eventually make the adjustment. I can already tell that these new arrows have quite a bit more thump, and that's a good thing. I think I'm going to fletch another one and start trying to group my fletched arrows before I finish them all.
If I'm grouping good then I think I'll leave everything the way it is? That is IF they will also shoot my broad heads?
Here's a couple of pics from outside and the first pics are 10 yards.
(http://i714.photobucket.com/albums/ww146/mohunter68/BareShaftTuning005.jpg)
Then these 2 pics are from 15 yards.
(http://i714.photobucket.com/albums/ww146/mohunter68/BareShaftTuning004.jpg)
(http://i714.photobucket.com/albums/ww146/mohunter68/BareShaftTuning003.jpg)
You never said but I'll assume you're a right handed shooter. If that is the case, your bare shafts look to be a little too stiff (nock right). You want your bare shafts to be a hair weak (nock left) because adding the fletching stiffens them up slightly. If I got that "nock right" reading I would increase my tip weight a little to weaken the shaft a little.
schlaggerman is right on the money! or you could take off your side plate and shave it down a bit on the back side you look to be very close. ive had bareshafts fly perfect and when fletched they went right by two inches at 20 yards.
Another option I forgot to mention, if you haven't cut down the other shafts yet, you can leave them a half inch or inch longer than your two test shafts. Only testing will tell you how much longer they would need to be to dial them right in. That way you can stay with the same weight tips you are now using. If leaving the rest of the shafts longer is the route you want to try, I would start with an inch longer and if they're too weak take off one quarter inch at a time until they're right on.
Hitting a little lower (due to heavier arrows) is fine. You just don't want an arrow diving down lower as it approaches the target.
I always start out 1" longer than expected with the point weight I want to shoot. Then cut them down 1/4" at a time until they are good.
ttt
Bag targets and the way they are packed and sometimes become compressed due to lots of shooting, can make reading the arrow a bit tough..
Is it possible to do your testing in a "block" or good 3D target? I think perhaps you'll get a better "read" on whats going on....
However, your results do indeed look good at this point.
Gene
i liked the way it was in the first pics.a little low and a tad right, is what i look for.fletched shooting like darts you say.thats also what i look for.Your like me ,like to mess with things even when its working fine.fun isnt it?
QuoteOriginally posted by schlaggerman:
You never said but I'll assume you're a right handed shooter. If that is the case, your bare shafts look to be a little too stiff (nock right). You want your bare shafts to be a hair weak (nock left) because adding the fletching stiffens them up slightly. If I got that "nock right" reading I would increase my tip weight a little to weaken the shaft a little.
You nailed it. I didn't have any trouble with this until I got back to further ranges beyond 20 yards and my arrows started drifting further left. I switched to a 145gr. head and that added another 20gr. up front, and my arrows came right back to center.
All isn't perfect yet, I still have a few other bugs to work out, but it's shooting fairly good at this point.
I haven't put a broadhead on yet so everything is subject to change when that happens.
The reason you shoot fletched with bare shafts(planing method for tuning popularized by OL Adcock)to compare groups is to eliminate all other influences to bs flight such as nock tightness and minor form inconsistencies. How the bs flies or impacts the target has nothing to do with anything using this method. Every thread on bareshaft tuning always has those who confuse the 2 methods or want to combine them often causing more confusion then help.
no you are not right on your bare shaft is too stiff. i'll say if you increase the point weight the point will stay the same but the nock will move left to match the fletched arrow. nock right for a right hand shooter is too stiff spine and the only way to weaken the shaft is to add point weight.I start with a full length shaft knowing it will be weak and then cut 1/4 inch at a time until the the nock hits straight in line with the point. It works for me
The calculator said my shaft was about 1.5 pounds stiff to start with and I should have known better to start there because my Grizzly likes them a little on the weak side anyway. I went from a 125gr. point plus 60gr. weight behind the insert, then the weight of the insert to equal 198gr. total tip wt, then I switched to a 145gr. point plus all the added wt. for a total tip wt. of 218gr. and they straightened out pretty good.
I'll either add more wt. behind the insert so I can shoot my 125gr. Snuffers, or maybe trade or buy some 150's??
I think the 150's have a wider cutting diameter if I'm not mistaken?
Thanks for all the help fellas, I may need some more before I'm done.
I'll bet with the added tip weight your arrows are flying better now, bareshaft or fletched. Good shooting Semo.
Yes and I noticed the increase in penetration. They sink much deeper into the target and thump quite a bit harder than my lighter arrows for my flatbow do. I can tell a definite difference in the added FOC and weight up front. These should flat out smack anything I wanna put one in.
Something else that's kinda weird, they really didn't seem to slow down much either? The velocity seems the same, but they hit with so much more authority and don't drop like I thought they would??
Is that due to the EFOC??
QuoteOriginally posted by SEMO_HUNTER:
The calculator said my shaft was about 1.5 pounds stiff to start with and I should have known better to start there because my Grizzly likes them a little on the weak side anyway. I went from a 125gr. point plus 60gr. weight behind the insert, then the weight of the insert to equal 198gr. total tip wt, then I switched to a 145gr. point plus all the added wt. for a total tip wt. of 218gr. and they straightened out pretty good.
I'll either add more wt. behind the insert so I can shoot my 125gr. Snuffers, or maybe trade or buy some 150's??
I think the 150's have a wider cutting diameter if I'm not mistaken?
Thanks for all the help fellas, I may need some more before I'm done.
Edit for total pt/tip wt change. That's 218gr. up front and not 208gr. I guess I'm mathmatically challenged today?
I did order some 100gr. brass inserts from Braveheart Archery today, so with my 125gr. Snuffers that will give me 225gr. up front and should be nearly perfect.
At least I won't have to pop for new broadheads this way. :thumbsup:
The pics look to be stiff.
I have a K-hunter that likes the arrow dynamic spine to be about 2lbs lower than the bow dynamic spine when setting up with Stu's calc. I also had nock right indication out to 30 yards bareshaft when I was running too stiff an arrow. When I get the arrows right I can group bare with fletched to 30 yards. The bare shaft will also stick in the target in the same relative plane as the fletched. provided nock point on string is good.
Your on the right track.
Good luck!
Brian