Limited # of pictures working on Photobucket . Still battling with Postimage.org
20 yards . Helical on right, offset left. Helical 377(396g arrow), offset 376
90 yards.
This picture was taken at the beginning of the test to evaluate whether the Goldtip video concerning the supposed advantages of helical vanes concerning long range trajectory applied to Xbow arrows. I shot at 20,40,60,80 and 90 yards.
Only pictures that would load on Photobucket are shown. The only vertical differences are shown at 20 yards(appx 1") and here, the opposite to the GT video occured : the offset was higher. At 40 yards , there was 1/2" difference. 60-90 were equal , vertically.
FYI, my M405 has an Optimizer and is set up for 445g broadhead tipped arrows. I was shooting 396g, field tipped arrows so I somewhat offset my Optimizer so the impact points would be near the middle of the Spyderweb. Aim points were the 2 lower, red hearts. Offset left, helical right. I used a benchrest set up. These arrows/Xbow will produce <1 1/2" 3-shot 100 yard groups . Excals aren't junk!
I didn't chrono at the various ranges except for 20 yds(377 helical, 376 offset) as trajectory was the object, not velocity. IF, there had been an appreciable trajectory difference, then long range velocity would have been explored.
Summary: same trajectory thru 90 yards for both offset and helical.
Previous testing: offset and helical have about the same accuracy with field points and very low profile Expandibles, helical has significantly greater accuracy for hi profile Expandibles and fixed broadheads.
Personal opinion: use helical only. Keep a minimum of 190g or greater insert/broadhead weight over nock weight for fieldpoints/low profile Expandibles and 200g or greater for fixed broadheads.
Hope this helps put this trajectory thing to rest: they're equal.m
