Do large, fixed blades on a BH create drag (v. FP's)?
If they do....would it be unusual for your BH tipped arrows to impact lower than your FP tipped arrows at extended ydg's?
Does the length of the BH tipped arrow (v. FP tipped) have any effects on arrow flight? If so...what would it be?
Thanks.
Drag is directly proportional to surface area. The larger the surface area of the head, the greater the amount of friction (drag) that is experienced. So yes, BH's will have more drag than FP's. That said, I highly doubt you would notice a difference even at extended yardage. Arrow tuning and mass are FAR greater factors in calculating trajectory.
I started by bare shaft tuning. That got me close.
I then moved to about a 10' paper tuning session. That got me dead-on....or so I think....or thought.
I'm getting perfect arrow flight with FP's and BH's....BUT...I'd be lying if I said they were impacting dead-on at 25-40yds. My BH's are hitting just under my FP's.
I was wondering if there were reasons "why"? Can I attribute this to additioanl drag created by the blades of the BH (v. FP's)?
Does the length of the BH (v. FP's) affect arrow flight in this manner (can it)?
If gap shooting or referencing the shaft end in anyway Broadheads might be altering your sight picture. With them generally being longer this will cause you to hold slightly lower. It's not a drag factor but a visual difference.
This is similar to having light shine on a front sight of a firearm. It can alter point of impact by making the edges of the sight look different
My point-on distance is shorter with broadheads, because the longer head causes me to hold the bow a tad lower. I don't think there's any real trajectory difference.
So....if there's no trajectory difference....are we to assume that the feathers create drag (thereby slowing down the arrow).....and the BH blades DON'T create more drag (which whould slow down the arrow) than FP's?
Just asking. Do the blades on a large, fixed blade head create drag? If so....at what distance would it become discernable?
Let's assume 170fps.
I think there would be a distinct difference at 146.532 yards.
...does that mean that my abowyer whitetails at .072 thick have twice the drag of my magnus I at .035 thick ? ...or would it be squared? ....single bevel vs double?
I suspect that the drag of the feathers overshadows any difference between point styles. I always figured a cutting-tip broadhead would have less drag than a field point, because of the sharp tip and gradual taper. It's all about disrupting air flow.
Anybody ever bare shafted a BH?
I'm thinking they (BH's) create drag. If it isn't up to the level of a legitimate question for you guys.....I apologize.
George :biglaugh:
Jeff,
I know you are new to trad....and you've been around here asking questions for a few months....and that's great, as you've asked a lot of good questions that needed answers for a converter. That's how we learn.
However,.....
The season is approaching, and its time to loose the field points and start shooting the Bheads exclusively. Its time to take what you have learned and put on your game face.
Every hear the expression...'Pickin flies outta poop'?
I think you are now over analyzing to the point you are now pulling the wings off of the flies that are on the poop.
This is not a slam, but a reality check I'm giving ya...so please don't take offense.
Take a deep breath and slow down....Concentrate on your shooting and start scouting.
Best of luck to ya during your 1st season as a Trad Bowhunter.
:campfire:
I don't take that as anything but corrective criticism, Terry. It's appreciated.
I'm an analytical SOB, though....and when something's occuring....I'm just one that needs to know "why".
I've bare shaft tuned. And, with the aid of pebowbwnder, I paper tuned. I've never been more confident in a setup.....compound or trad.
But...at distances beyond 25yds....the BH's are hitting a little lower than my FP's. They just are. I wanted to know "why". I've been shooting BH's for several weeks, now....and you're right....it's time to simply lose the FP's.
I'll punt. Good luck to all of you. We open next Sat.
No worries Jeff....
BTW..be VERY carefull if you decide to Bare Shaft Bheads.... :readit: :readit: :readit:
And if they are flying fine, I sure wouldn't fool with anything this close to the opener but shootin and scouting.
Best of luck to ya Saturday and beyond. :thumbsup:
Oh I know better than that....lol. I was trying to make a point (why you DON'T bare shaft BH's).
Thanks, again.
Terry's right, as a Detective I am often put in line by a statement my Crime Scene Investigator makes when I try to analyze the obvious. "Over analysis leads to paralysis"
Glad you are confident in your set-up amd best of luck. Oh yea if this phenomena occurs at greater than 25 yards just shoot em at 10
If your broadheads are flying great then shoot'em!!!
Good Luck and post pics... :thumbsup: :thumbsup: :thumbsup:
I think the BH's having 'more drag' are causing the elevation difference. You don't tell us how many inches "just under" really is.
Jeff, if you can download a copy of Easton's Tuning Guide and look at Fig. 20, it shows that one should lower their nocking point, if the broadheads are grouping below the field points.
If you have a brass nock set, you can open it slightly, then "screw" it up or down to make very small changes in nock set position. We're talking 1/32" change at a time here.
If the BH's are landing an inch or so lower at say 20 - 25 yards, I'd say STOP, listen to what others have said, and focus on what else needs to be done to have a successful hunt. You can always resume that fine-tuning quest after season's end, whilst shooting on a full belly of venison & Merlot ;)
Well.....honestly they're impacting 3-4" low at 26yds (where my BH target is from my shooting platform). I have NO issues with lowering the nocking point....but I'll ask this.....
When I paper tuned (from 8-9') with FP's....we micro-tuned the nocking point. I'm getting perfect tears from that distance.
Would you still attempt to lower it....knowing it would go against your paper tuning findings?
I appreciate this....honestly (the corrective criticism).
Thanks.
"Would you still attempt to lower it
....knowing it would go against your paper tuning findings?
Yes.
Paper-tuning is not a final absolute answer, especially at only 10 feet.
"...knowing it would go against your paper tuning findings", er, you may want to test that conclusion before arriving at it :)
If I hit within 3-4" at 26 yards, I'm happy!
OY...
I'm curious....so you're saying paper tuning at those distances isn't accurate (or...."might" not be)?
I REALLY appreciate the help.
Don....
I'm NO crack shot. But the "low" results are consistant. Not left/right/high (and "off", that amount). They're all that much low.
I'm suggesting to leave go of the paper tuning for now, and try the nock-set tweaking, see what you come up with, & learn from it. I don't think any one tuning method is an absolute.
BTW, if you want to really drive yourself barmy, build 3 paper tuning frames, set the 1st one up at 15', 2nd at 17', 3rd at 19', and see if all three show a bullet hole :wavey:
Jeff, once you get a good tear at ten feet you need to move back at shoot from other distances. The arrow could be in a recovery position at ten feet. As an arrow wobbles up and down it could be hitting the paper at that moment in time when it is straight. If I remember right you moved your nocking point when you went from bareshafting to paper?
The whole point of tuning is to get your broadheads to impact exactly where your field points do.Yours are very close but at that distance,not quite.
For my setup,moving the nocking point 1/16",moved the position of the group 8" at 20 yds.I don't know how your bow would react but I think I would try 1/32" or less.
Longer distances and broadheads show minor discrepencies in tune and it sounds like that is what you are seeing.Still,very,very close.
The ultimate broadhead dynamic is for it to hit the animal while flying perfectly....with all of the energy focused on the tip of that arrow. If that happens, you don't need to worry about Newton's Theory, or the price of TastyKakes in British Columbia. Put the broadheads on...get them flying "perfectly", and forget about analyizing so much.
I also have an analytical mind, Jeff, but mostly I'm trying to figure out if I want to Barbeque those back straps, or fry em' up. 8^).
Let me ask ONE more question.....lol.
Bare shafting is a good start. Paper tuning is a way to sort of check your own work (from bare shafting).
If I move my nocking point down a hair....is the final test (and I suppose the ONLY one that matters) simply my POI (BH v. FP)?
I'll sling a few this afternoon.....and report my findings.
Thanks, guys.
Like I've stated....it's darned close. I'm confident of that.
Nothin wrong with Newton's theories either.
Like I said originally, it's highly unlikely that there is enough drag created by a BH over an FP to see any difference at all, especially at 26 yds.
More likely you are dealing with:
1) different tuning dynamics
2) different gap due to BH length
3) different sight pic
4) pulling the bow differently (or other form issue)
5) something in your head that is causing you to shoot low
The physics of it just won't work out to 3+ inches low. There's nothing wrong with being curious, just so long as it doesn't effect your shooting. Good luck and happy hunting!
I switched to 100% BH's, yesterday.
I'm "good". I appreciate everyone's indulgence (sincerely).
Confidence is essential. Shoot BH's until you're certain they're hitting where you look. Go with it.