2 or 3???

[sector42]

Actually the orientation of a broadhead does make a difference that will show at yardage. As a release shooter the most prolific oscillation of your arrow will be up and down ( side to side for a finger shooter ). A two blade broad head launched in the horizontal plane will track in the position of first oscillation. One should make every effort to align two blade head vertical, like an I

Four blade heads can also have this problem if launched in a + pattern. Indexing a four blade head in a X pattern keeps the blades from having a full profile in the oscillation plains.

Three blade heads do not have the problem of a two or four blade as only one blade can be in the horizontal or vertical plane at launch. Aligning a good three blade head with fletching is not as important as having your stiff spine side up or down with all the arrows used with a three blade making sure you have enough fletching for the three blade head.

Mechanical heads are not as subject to the alignment as they are not a full profile head and the plane effect during oscillation is reduced. All heads can benefit from these practices. Physics is physics.

Great post JBS. Very good information. I will check my allignment when I get home and study my physics as well.

[sector42]

How do you tell where the stiff spine side is on the arrow? Is it marked?

[coachk43]

I shoot 4 blade 125 grain Muzzy Phantoms... Nothing has gotten over 120 yards that I've hit and most pile up within 50yds

[JBS]

How do you tell where the stiff spine side is on the arrow? Is it marked?

I made one, instruction are at this web page. There are commercial units made but they will cost a lot more. The old way was to plug both ends and float the shaft (Alum) in the bath tub, The stiff side would be down. This does not work as well with carbon shafts so most people use a dial indicator on a tester bench. http://www.jamesmhill.com/Spine_Tester.html

Note: some vendors will mark the spine for you when you order shafts from them, for a added fee.

[JBS]

this is about what I was looking for... the only thing I don't understand is why release shooters' oscillations are up and down??

Maybe this will help. Very good article by Daniel Grundman, who is a great guy to visit with.

http://www.flexfletch.com/interactive/articles/the-mechanics-of-arrow-flight/

[Ol' Squeek]

You do NOT have to align anything with anything. Fixed or mechanical it does not matter. 3 blade BHs have mostly gone to the way side because people learned that you get more cutting surface area with an extra blade. A lot of the expandable BHs are 3 blades, but the slider/rear open style tend to be 2 blades, because the mechanics is easier to work out.

I have found that the more parallel the limbs on a bow the better it shoots 4 blade BHs, or ANY mechanical BH. 2 or 3 blade styles.

this is caught my attention also..my dads mission x4 soesnt have the close parellel limb design and shoots 4 blade muzzy's and 3 blade thunderheads with no problem..