Weird shooting results between arrow weights

[Desmond]

Ok fellas ,

Here's a "dandy" case for you to analyze and figure out a logic explanation for the following:


Last night I shot my bow after I installed my new Madman 2X4 quiver on it. I shot two different brands of arrows with different weight obviously.
The lighter arrows are my new 29" Vapor Pro series 4000 with blazer vanes and 100 grains f/tips with a total weight of 397grs and the heavier arrows are 30" Carbon Tech Whitetails XP with shield type of vanes plus are wrapped and with 100 grs f/tips also for a total weight of 443. Both arrows have a spine of .001. My Slayer is still set at 30"D/L and limbs are maxed out with 66pounds of weight.

If you're wondering why I'm shooting two different arrow lengths , it is because I've been battling some health problems and had gain around 110 pounds of weight in about over a year and thanks to Lyme disease, liver and back problems plus rheumatoid arthritis I was in bed for six months. My draw length changed from 30" to 29". I didn't want to bother on adjusting my D/L 'cause as of now I'm on treatment , on diet, going to the gym and on my way to a full recovery . God willing!

Anyhow,...

Here's the the weird thing:

Shooting at a distance of 20 yards, my lighter arrows which are an inch shorter, are hitting below the heavier and longer ones. But I get a slight better penetration from the lighter ones. Why??? :confused:

I'm a bit "rusty' due to my body and health issues, but I did shot a few sets of three of each arrows and the results where similar every time.


Heavier arrows fly "flatter" and closer to the 2.5" dot.

http://i72.photobucket.com/albums/i171/GILB8/Photo0003-1-1.jpg


Better penetration with the lighter arrows

http://i72.photobucket.com/albums/i171/GILB8/Photo0002.jpg

[alex]

Just guessing, but i can see 3 reasons for this-1.the different vanes, causing different planing(if this is the right word) during the flight;2.the greater speed of the lighter arrows and 3.may be some psycological effect of shooting the heavier arrows causing a slightely higher aiming. But of course i can be completely wrong :D ;)
P.S. Desmond, i hope you'll be ok with your health!

[flytier17]

Not gonna speculate on your particular case as I have never shot either arrow. But, heres some things that might affect penetration and flight.

The highter drag the fletches are, the faster they will lose speed. I minimal drag fletched arrow might be 3-7fps faster @ 20yds. than a highdrag fletched arrow of the same type. For example a miniblazer fletched straight or a 1.75" Flex-Fletch with minimal offset vs. a 4" Quickspin or 5" helical feathers.

The width and texture of an arrow will determine penetration. Especially when shooting into industrial plastic wrap (a common bag stuffing). The more surface area is exposed, the more it will be slowed easier. Also, a blunt point might retard penetration too. Field points will penetrate less than bullet points for example.

Density of the shaft will also be a determinate as to how much energy the arrow absorbs. I shoot FMJ's for hunting. They are really dense-walled shafts. Just for interests sake, I shoot an identical weight aluminum, both with no fletches. The density of the FMJ absorbed energy more effeciently than the aluminum, and was 2 fps faster. This could affect flight and penetration.

All the best with the health struggles. I hope your recovery is speedy and troublefree, and I hope you are shooting to capacity again soon as well.

Alec

[Desmond]

Thanks guys for the well wishes concerning my health. I'm looking forward to a full recovery and enjoy them woods along with my son! :) Lyme disease in particular ,... it sucks!! :mad:

As far is for these results i had with these arrows, I don't want to think that 'cause of the new quiver probably is affecting my/bow's center of gravity not the difference in arrows, but probably it's my actual physical/health condition. I'll certainly will be practicing more often as I can and of course,.. will be bringing the results to share and discuss here.

Thanks again and may all have good health and straight shooting!!:D

[bowgramp59]

all my lighter arrows shoot higher than my heavy ones, your results are a little strange. i use 2" blazer vanes on some of my arrows and 4" savage dura vanes on some , when they are close to the same wt. they hit the target at the same place, in the bullseye sometimes. i like to experment with different lengths and diffrerent wts. i've come to the coclusion that a 27" 410 grn. arrow shot from a 2009 moab at 50# draw wt. is the best for me

[scepterman30x]

What is the dia. of either arrow? The lighter arrow that is hitting lower may have a smaller dia. than the heavier arrow hitting higher. Even the slightest difference in dia. will cause a change in impact.

[b0w_bender]

It is possible that the longer arrows are tuned to the bow and as such the bow is transferring the energy more efficiently. Yes they have the same spine specification but length of arrow and point weight also affects it's spine. So perhaps the shorter arrows are leaving the bow more sideways and not able to absorb all the bows thrust.

It would be helpful to know the distance you are shooting here. I would also be curious to see how they perform at multiple distances so we could get a better idea of the arrow trajectory.

But I would start by paper tuning the shorter lighter arrows.