BOLTS CHANGING TRAJECTORY

[CT.HNTR]

A friend shoots a Matrix 355. The bolts we built for it are 18.00 long zombie slayers with 110 grain brass inserts. Using blazer vanes and 100 grain Slick Tricks. He has shoot two deer with it and we have noticed something we don't understand. He is shooting from a tree stand 20 feet up and the deer have been 20 yards away. This works out to just over a 19 degree angle to the target so we are expecting the exit wound of the bolt to be about 6 inches lower than the entry if you figure the deer to be about 18.00 wide.

What's puzzling us is the entry and exit wounds are even or parallel so it's almost like the bolt is changing it's trajectory on entry and flattening out.

Is this possible? has anybody seen this before?

Both deer have been shot center of the chest right behind the shoulder.

We are struggling to understand this phenomenon!

[xcaliber]

Check your trigonometry.

[Tom]

Yes a bolt will change trajectory on entry.

The tail end of the arrow has less friction then the tip which is now cutting meat and bone.

If you shoot an arrow into water to hit a target, you need to aim low as the arrow deflects towards the water surface (bow fishermen understand this fact).

You also have the factor that the deer can and will move which causes different trajectory with different shots. The thing is the difference in the trajectory is usually minimal and not causes bad hits. Plus you head might has struck bone to cause a change.

Tom

[Riflemanz]

As long as he’s killing deer don’t sweat the small stuff.

[CT.HNTR]

Check your trigonometry.

I triple checked the math and it is dead nuts. Even laid it out in SolidWorks. A right triangle with a height of 20 feet and a base that is 57 feet (19 yards) will have an angle of 19.335 degrees. With this angle and a deer that is 18.00 inches thick the exit wound should be 6 inches lower than the entry.

[xcaliber]

Okay, good skills.
Deflection is always going to occur in some way with bow hunting. I would not worry about that too much, probably more normal than not I would think. Congrats on the deer!

[Stepnoutnb]

Check your trigonometry.

I triple checked the math and it is dead nuts. Even laid it out in SolidWorks. A right triangle with a height of 20 feet and a base that is 57 feet (19 yards) will have an angle of 19.335 degrees. With this angle and a deer that is 18.00 inches thick the exit wound should be 6 inches lower than the entry.

Here's a short video showing a branch deflecting the arrow into a tree and then missing the deer. This being my first crossbow I can only GUESS a glancing hit on a rib or bone of some sort could/would make an arrow do some funky stuff. Congratulations to you pal.

https://www.youtube.com/watch?v=mk-LGW1tRHE

[Stepnoutnb]

Check your trigonometry.

I triple checked the math and it is dead nuts. Even laid it out in SolidWorks. A right triangle with a height of 20 feet and a base that is 57 feet (19 yards) will have an angle of 19.335 degrees. With this angle and a deer that is 18.00 inches thick the exit wound should be 6 inches lower than the entry.

Here is another video of an amazing deflection inside an impala. This deflection is almost hard to believe. This is some great footage.
Enjoy
Wayne

https://www.youtube.com/watch?v=tsLEKrTtx5k

[Tom]

................
Deflection is always going to occur in some way with bow hunting. I would not worry about that too much, probably more normal than not I would think. Congrats on the deer!

Arrows do not fly a flat trajectory! They do not fly like a lazer beam.

There are way too many factors that determine the flight path of your arrow. Wind, branches, grass, extreme angles, movement of the animal, structure on entry all can cause the arrow to change dirrection, sometimes minor and sometimes major.

Tom

[CT.HNTR]

Wow!

That deflection inside the Impala is remarkable.

[Stepnoutnb]

Wow!

That deflection inside the Impala is remarkable.

Yes everyone should watch that video. Very educational.

[dithian]

Amazing video! That may explain a couple of my past hits.

Deflection aside, I know that deer will duck to load their legs, and tend to roll away from the sound of the incoming arrow. If they roll away, the exit wound will sometimes be considerably higher than expected. The exit wound may also be further forward than expected—I've had deer go from perfectly broadside to 3/4 quartering in the time between trigger pull and impact.

High speed camera on the bow would sure be helpful for the post-mortem analysis.