Sitka Mountain Gear
Standard to micro diameter arrows
Equipment
Contributors to this thread:
TODDY 12-Apr-20
LINK 12-Apr-20
Matt 12-Apr-20
MtnHunter 12-Apr-20
PECO 12-Apr-20
Trial153 12-Apr-20
Medicinemann 12-Apr-20
x-man 12-Apr-20
Bou'bound 12-Apr-20
TODDY 13-Apr-20
weekender21 13-Apr-20
bowhunter24 13-Apr-20
CCOVEY 14-Apr-20
12yards 14-Apr-20
Ermine 15-Apr-20
Kurt 15-Apr-20
bigdog21 15-Apr-20
RD in WI 15-Apr-20
grossklw 15-Apr-20
x-man 15-Apr-20
Habitat 15-Apr-20
Kurt 16-Apr-20
Bou'bound 16-Apr-20
Kurt 16-Apr-20
x-man 16-Apr-20
Kurt 16-Apr-20
x-man 16-Apr-20
Kurt 16-Apr-20
x-man 16-Apr-20
x-man 16-Apr-20
Kurt 16-Apr-20
x-man 16-Apr-20
x-man 16-Apr-20
Kurt 16-Apr-20
HH 16-Apr-20
Shawn 17-Apr-20
x-man 17-Apr-20
Kurt 17-Apr-20
bb 17-Apr-20
x-man 17-Apr-20
HH 17-Apr-20
JB 18-Apr-20
x-man 18-Apr-20
Kurt 18-Apr-20
x-man 18-Apr-20
Kurt 18-Apr-20
x-man 18-Apr-20
TODDY 18-Apr-20
Kurt 18-Apr-20
x-man 18-Apr-20
x-man 18-Apr-20
Kurt 18-Apr-20
From: TODDY
12-Apr-20
For those that have changed from standard diameter to micro diameter arrows, was there any fine tuning needed to make that happen? Thinking of making the change this year. I have a fallaway Ripcord arrow rest. TODDY

12-Apr-20
Interested to read these, thanks.

From: LINK
12-Apr-20
No idea on tuning. After watching the Corey Jacobson video a year ago where the guy runs a broadhead into his leg, I’d think a quiver that holds them tight would be good.

From: Matt
12-Apr-20
You would at a minimum need to raise your arrow rest to account for the difference in OD.

From: MtnHunter
12-Apr-20
Yes. There are tuning differences, minimal but you your rest will need adjustment to account for smaller diameter, in all directions up/down and left/right.

From: PECO
12-Apr-20
Wouldn't left and right be the same, if your center shot is correct?

From: Trial153
12-Apr-20
You most likely will have to make a few adjustments. The arrow build will be slightly different and therefore you will have a slightly different dynamic spine all else being equal. I would just plan on doing a full re-tune even though you most likely won't be starting from scratch.

12-Apr-20
What are the main advantages besides less wind effect on the shaft? Are they faster, offer significantly better penetration...? When I picked up my new bow the guys wanted me to change from GT to a small diameter. I did not have enough knowledge so I stayed with what I knew. Thanks.

From: Medicinemann
12-Apr-20
I did a lot of research on smaller diameter arrow shafts when I was preparing for a 2015 elephant bowhunt. There was a considerable advantage in penetration, since the arrow shaft was smaller than the broadhead ferrule.....once the broadhead penetrated, arrow "drag" was much less of factor. I did not see an appreciable increase in speed.

From: x-man
12-Apr-20
There wouldn't be any increase in speed unless the overall weight was lower. Penetration would naturally increase in harder tougher medians but not so much in soft wet tissue. Bones yes, thick tough skin yes, vital organs no. Tuning would be nearly identical if using the same point weight, length and spine of shaft. The rest would need to be raised slightly.

Changing for the sake of changing is up to each individual. In my opinion they are no better than standard carbon shafts for my whitetail hunting. The Victory VAP arrows that I bought some years ago for long range FITA style target competitions were actually a step down in accuracy. Under calm conditions my Carbon Tech arrows grouped much smaller than the VAP arrows. And in high wind conditions, the wind affected my bow much more than the arrows so having the skinny arrows didn't help my score at all.

I'm not saying they are a bad decision, just that they offer no advantages for any of my shooting.

From: Bou'bound
12-Apr-20
Is 5mm considered micro

From: TODDY
13-Apr-20
Thank you for the info! I want to start making my own arrows and was considering a switch from standard size Victory arrows to TKO's. TODDY

From: weekender21
13-Apr-20
You will possibly need to make a very small rest adjustment but not always. I know it's obvious but the details matter; 5mm OD to 4mm OD will be very little difference and may not require any adjustment.

From: bowhunter24
13-Apr-20
Shoulder surgery put me down to 50lbs draw weight and the smaller dia. Easton injections with a 50 grain outsert required a new target as my old target wouldn't stop them.

From: CCOVEY
14-Apr-20
you'll likely have to make some adjustment, like switching from any arrow to another.

From: 12yards
14-Apr-20
I really find it hard to believe that penetration is going to really be that different. The broadhead is going to cut an absolutely massive hole compared to the diameter of a standard or micro diameter arrow. I like standard diameter shafts. They are easier to fletch, have better inserts, and IMVHO, are more durable than the micro diameter shafts. Maybe if I was primarily an elephant, rhino, Cape Buffalo, or big hog hunter, I'd switch. But for everything else, I'm going with the standards. And my wallet will be a little heavier besides.

From: Ermine
15-Apr-20
I think it’s always a good idea to check and retune when your switch arrows.

I like the microshafts. They cut the wind good. I’ve had great success with micro shafts last few years.

From: Kurt
15-Apr-20
I like the micros too. Put the D-6 insert inside for weight and mainly reinforcing, then use an outsert so you can use std threaded broadheads and field points.

From: bigdog21
15-Apr-20
what on earth are you guys trying to kill. 2216/ 125r blows threw everything I shoot.

From: RD in WI
15-Apr-20
Randy Ulmer via a 2017 article: "Buy the best arrows you can afford (price is almost always commensurate with quality). Use a small diameter, very straight, slightly stiff, reasonably heavy arrow with just enough fletching to adequately steer the broadhead." Mr. Ulmer is an accomplished hunter with a quality mind - I took his advice and have been satisfied with the results. Additionally, his article expounds on his views that a heavier arrow quiets a bow better than other methods. I have never had a whitetail jump the string and it only shoots 244 fps with a 460 grain micro diameter (.166) shaft. Good luck in your arrow search.

From: grossklw
15-Apr-20
I've been shooting VAP's for the past 5-6 years. The early outserts had significant problems with bending and it was impossible to tune. I haven't had any issues with that over the last couple dozen arrows I've went through, shooting 30ish arrows a day all summer.

If you have a tight spot quiver; staying in the quiver isn't a problem because you can adjust the tightness. Had a buddy that lost all of his arrows because he didn't adjust his old mathews quiver to this and it was expensive for his time (4 mile hike to get more).

In terms of penetration it probably matters some, but I can't imagine it's ever a difference between killing or not killing an animal. I went that route more so for wind than anything else. I've had complete pass-throughs on 3 elk in the last 4 years including one at 50 yards and have nailed a whitetail doe to the ground through both shoulder blades just because I wanted to see if would do it. One other thing though, is they are a giant pain in the ass to remove from foam targets.

From: x-man
15-Apr-20
I would wager that there is very little difference with regard to wind drift. It's the broadhead blades and fletching that catch the wind more so than the shaft itself.

From: Habitat
15-Apr-20
You will have to buy a new quiver for sure there are a couple different ones for micro arrows

From: Kurt
16-Apr-20
If you shoot a Tight Spot and micro shafts, just tighten up the grippers, no need to purchase anything.

The maximum wind drift would be the effect of a 90* side wind on the shaft, the fletching and the broadhead. The most impact to the wind is the shaft: for my Easton Carbon Injexion micros the area pushed on including an outsert is about 7.19 sq in....or 81% of the total arrow.

The 2" Blazer vanes have a a side profile of about .96 sq affected by the wind....11% of the total.

The 3 blade NAP Spitfires closed up has a total broadhead side profile area affected by wind of .67 sq in.....8% of the total.

So wind pushes on about 8.82 sq in of arrow in my case. 81% is on the shaft, 11% on the fletch and 8% on the broadhead. Your results are likely to be different as this is a very sleek arrow, micro diameter shaft, average sized plastic vane and a small profile mechanical broadhead designed to minimize wind drift (and other flight issues). Note that areas are approximate in my calculations but are very close.

In looking at my previous generation of "regular" carbon arrows....Gold Tip 55-75 XT Hunters I found they had about 12% more wind deflection potential based strictly on shaft section perpendicular to a side wind, but they were lighter and flew faster, likely negating the added wind drift caused by the larger shaft diameter versus the Injexions.

My old finger shot arrows were 23-15 XX75 aluminums, 4-fletched with 4 @ 5" feathers tipped with 4-blade Zwickey Delta broadheads. These arrows had 87% more potential wind drift at the same velocity, but were slower so drifted even more. The eye test showed that to be the case.

From: Bou'bound
16-Apr-20
Is 5mm full metal jacket considered micro

From: Kurt
16-Apr-20
4 mm (inside diameter) 330 Carbon Injexions say “Micro” right on the labeling. Doubt 5 mm shafts will say Micro on them but don’t own any nor have I ever looked at them so do not know definitively.

From: x-man
16-Apr-20
Kurt, your math is flawed. The shaft is a cylinder. The aerodynamics of a cylinder are quite different from the flat face of a vane. And don't forget that there are always at least two vanes in contact with the side wind. If figuring a 90* perpendicular side wind, the only part of the shaft that is 90* to the wind is the razor-thing leading edge. Less than 2 square inches. The rest of the "side of the shaft" has progressively less drag. The differences between a 4mm shaft and a 7mm shaft are pretty minimal.

Take four arrows in the car with you. One bare shaft micro, one micro with vanes & fixed blade BH, one bare shaft standard, and one standard with the same vanes and BH as the micro. Hold each out the window and pay attention to the drag felt in your hand. It will be clear to you as it is to me that the shaft size has very little impact by comparison.

Using the full surface area of the shaft is as flawed as using the full surface area of your bare hand out the window. The air-drag is quite different depending on the position of your hand...

From: Kurt
16-Apr-20
I used the area of the projected plane ie the shaft is 28” long x .243” dia plus the projected area of the outsert. A side wind can only push on the side of an arrow.

As per the vanes, the side wind pushes on about 1.5 vanes at a time on a 3-fletch arrow. (4 fletch would be 2 vanes at a time.). Similarly with 3 or 4 blade broadheads.

Let’s see your math! We are talking about wind moving a shaft sideways here, not how sleek the shaft is for a headwind

From: x-man
16-Apr-20
You can't use .243" unless the shaft is square(flat). Like I said, put your hand out the window like this --- and then like this l . It's the same "surface area" but it definitely has more wind resistance like "l" than like "---".

You can use your math somewhat to compare one shaft to another, but the percentage of wind resistance caused by the fletching and blades exceeds the shaft itself.

From: Kurt
16-Apr-20
Since the shaft is round you can use the projected area as I've done. My hand has a different projected area when rotated 90*. Mine would be about 40 square inches palm facing 90* to the wind direction and about 10 square inches rotated so the length of the thumb is oriented into the wind. So yes, 4X more drag if you change your hand orientation...not so with a round shaft.

From: x-man
16-Apr-20
You can only use the projected area if it is all perpendicular to the force applied. That math only works if the shaft were square with flat edges. You need to reduce the projected area exponentially as you go up and down from the center-line.

From: x-man
16-Apr-20
According to the article "Wind and Structures An International Journal " the affects of flow over a circular cylinder range between 50-60% of the projected surface area depending on the surface characteristics (how smooth it is).

So assuming a worst case scenario, projected surface area x .6 = affected drag coefficient.

From: Kurt
16-Apr-20
Using your data, derating the projected shaft and broadhead ferrule area by 50% for a cylinder gives the following:

The shaft comprises 72% of side wind load, Blazers 19% and the Spitfire 9%. So the shaft still is the major factor in wind drift.

From: x-man
16-Apr-20
50% of 7.19 is 3.595"

Two Blazers = 1.5"

Two fixed blades = 1.5"

Total surface area 6.595"

Shaft- 54.511%

Fletching & Blades- 45.489%

Yes, the shaft carries the majority, but the difference between these numbers and the same formula used on a standard carbon shaft indicates a wind drift savings of approximately 4% by using micro diameter shafts. Which probably translates to less than 1" drift at 60 yards.

From: x-man
16-Apr-20
If either of us needs to "check the math" I can involve my wife. She has her masters and teaches college math including college algebra, calculus, and abstract algebra. She'll roll her eyes at me but, she'll do it.

From: Kurt
16-Apr-20
X-man, We are in close agreement and get the same affected area on the shafts of 3.6 sq in.

The surface area of the old Blazers I have measure closer to .64 sq in versus your assumed .75 sq in. Close enough. Since I use 3 fletch, not 4, I assume that the side wind only pushes on 1.5 Blazers at one time so only come up with .96 sq in affected for the Blazers.

My 3-blade Spitfire mechanicals only have .13 sq in of exposed blade area each. Since they are 3-bladed, I multiply by 1.5 for a blade area of .20 sq in. The ferrule has a projected area of .47 sq in, but I derated the section by 50% as it basically a tapered cylinder to come up with .24 sq in. The Spitfire total broadhead section of .44 sq in is what is affected by wind.

Total arrow has 5.0 sq in of affected area.The shaft comprises 72% of side wind load, Blazers 19% and the Spitfire 9%. So the shaft still is the major factor in wind drift. I stand by my calcs.

From: HH
16-Apr-20
Shoot Black eagles

There is a biig difference between nanos and 6mm even.

Shoot both see how much further the small Dia penetrate.

The fly much flatter as well. They really shine at ranges past 45yds!

K

From: Shawn
17-Apr-20
I went from regular down to 5mm and did not move a thing. Paper tested perfect and grouped broadheads out to 60 yards just fine. I also chose a shaft that weighed the same 9.4 gpi. and same .400 spine. Shawn

From: x-man
17-Apr-20
Kurt, each Blazer has .96 less a percentage for reduced angle =.75 x 2=1.5. You are the only person here considering mechanical BH's. My original post references fixed blades.

If we remove both the BH's and the vanes from the equation, and only consider the shafts. The micro shafts still don't drift a noticeable distance further than standard carbon shafts. Which was the point I was trying to make. Along with the fact that wind affects the bow far more than it affects the arrow flight with regard to misses.

From: Kurt
17-Apr-20
Why I did the math was to show the shaft's impact on wind drift is significantly more than the broadhead and vanes combined. Even with a 4-blade Zwickey Delta up front utilizing the same Blazer vanes and micro-shaft, the shaft would still comprise 64% of the side wind loading.

From: bb
17-Apr-20
I used to shoot the original pultruded carbon Beeman arrows that were made in France. I liked them alot they were thin diameter, Broke fairly easily, they used outserts to attach broad heads but I used glue on Muzzys that were made specifically for those arrows. They had very impressive penetration in targets, penetrated much deeper than the aluminums. At the time there were no other Carbon offerings. So it was either Beeman Carbons or aluminum. The one thing that I came to realize early on was that even though they penetrated targets substantially better than standard sized arrows, it made no difference with shooting animals. the broadhead opened up a hole that was much larger than either the thin arrows or thick arrows plus blood and muscle tends to add lubrication that you don't get in foam so any perceived advantage in penetration was non existent when shooing at animals.I have shot animals ad distance in strong winds with both thin and thick arrows, frankly I have not been able to see any measureable difference in point of impact due to wind drift by either size.

From: x-man
17-Apr-20
I agree bb.

The micro shaft is a fad that will fade out just like single cams. Bowhunters are sheep and will blindly follow most successful celebrities' advertising campaigns. They will also go down with the ship defending their purchases.

If "Chuck" says it's like throwing an ax through the animal...it must be true. If "Randy" says it's the best thing he's ever used... it must be true. Never mind that they're paid to read or write a script... Never mind the practical logic...

From: HH
17-Apr-20
I shoot my Black eagles with recurve. There is a very big difference in vertical and wind drift at those speeds. If there was no advantage at all the Olympic Recurve class would never use them. There is not much for a that guy to win using a standard shaft. They fly flatter and drift less. I shoot to 80yds with recurve and the drop with standard shafts you need to shot 47-50lb bow depending on draw length. Where with a Nano you can you can get there easy and flat at 40-42lbs. To compare when you just put the outsert on the nano shaft with a practice point it already puts very noticable drag and vertical drop on the shot. With a broadhead a lot more drag. They will shoot very well at longer ranges without question. I have never shot them with broadheads against a standard shaft side by side however.

K

From: JB
18-Apr-20
It's always interesting when some x-pert calls us sheep that will blindly follow the celebs. I made the switch to micro to get heavier with it. Have been extremely happy with performance. But then again I'm probably just going down with the ship.

From: x-man
18-Apr-20
HH,

The X-10 shafts used in the Olympics would be considered a "standard" diameter carbon shaft, not micro. You are absolutely correct. In fact, they are double-tapered, barrel-shaped. The center of the shaft is has a larger diameter than the ends. If the new micro shafts had an advantage over them, they would be using them. Rick McKinney of Carbon Tech developed the McKinney micro diameter target shaft many years ago, and then the McKinney-II later on to compete against the Easton X-10. Guess what, there was no noticeable difference in wind drift at 70 meters. The X-10 shafts grouped tighter and had the same wind drift. That's why you see them dominating the Olympic podium. Those guys don't much care about sponsorships, they want the gold.

Thank you for cementing my point Jerry. Even though it seems you switched for weight reasons rather than wind drift. I'm glad you're happy with your purchase.

From: Kurt
18-Apr-20
X-man, where do you get your diameters for the Easton X10 ($400/dozen shafts)? The chart I saw (AT, Sean.Magnuson, 2015) shows a .380 spine X10 is .213" OD at the fat barrel and .142" OD at the crown...way thinner than "standard carbon arrow diameter". They have a smaller OD than their target competition at the fletch end and point end due to taper and are similar OD at the fat of the barrel to other high $ target shafts...and obviously very straight and consistent arrows.

From: x-man
18-Apr-20
I thought the unwritten rule of thumb here was that internal component arrows= standard diameter. External components= micro. I think I may still have one of my broken X-10's in the basement. I'll see if I can find it and take a picture of it compared to a hunting shaft.

From: Kurt
18-Apr-20
Internal components come in multiple sizes. The X10 have a .125" internal diameter whereas many other shafts target shafts appear to use the .166" dia components.

From: x-man
18-Apr-20

x-man's embedded Photo
x-man's embedded Photo
So now you're arguing just for the sake of arguing. I've been trying to educate, and you're just arguing. I'll stop trying. Attached is a picture of the tail end of an X-10 along side a Carbon Tech Whitetail that I used for outdoor long range target competitions. There's only six inches of the X-10 left. I had saved it to make a pen out of it. I sold the rest of them when I retired from competition. I don't have any of the new micro-diameter shafts on hand but, I believe they would slide inside of the CT Whitetail.

By internal and external components, I am referring to screw-in broadhead inserts and/or outserts.

From: TODDY
18-Apr-20
So.....Still no firm decision on my part but I'm thinking a slight change possibly in vertical adjustment and likely not needing anything in the left/right as mentioned above. Thanks everyone for the help. :0) TODDY

From: Kurt
18-Apr-20
Just looking for facts which engineers like.

The picture doesn’t look like an X10 that specs show are .142” OD at the tail. What is the diameter of the tail of the arrow between the nock and fletch? Did they change the X10 in later years to a smaller diameter at the ends? What era is your “X10”? Anyway, the specs shown in the referenced chart are for a shaft that is very sleek. Your picture surely shows a shaft that appears to be std size, or at least in excess of 1/4” in diameter?

From: x-man
18-Apr-20
It's a long story but, those were Justin Huish's "practice arrows" from 1996. Not the actual dozen he used to win gold.

From: x-man
18-Apr-20
They are actually very close to the OD of an Easton Axis arrow. And no, I wouldn't classify axis shafts as "micro" because they still use internal point inserts.

From: Kurt
18-Apr-20
Easton must have remodeled them in later years. They are apparently a lot skinner today based on specs I read...why would that be? Thanks for the debate. Fun while working on home projects!

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