Chronograph Problems

[RedStag5728]

Hey guys, to start off I am not particularly nutty when it comes to the speeds of my bows (especially my selfbows) but I do like to compare them and to also see how well they shoot and if the bow would be a good performer or not.

So I bought myself a Prochrono Digital Chronograph from 3rivers and shot my bows through them. My Redstag reflex/deflex laminated long bow was getting around 175 fps when I first got the chrony.

When I first made my eastern woodland style self-bow (the one in my signature), I shot it through the chrony and was getting upper 150s and even a few in the 160s.

I just took it out today and shot under clear conditions, etc. My Redstag shot consistently in the low to mid 150s, and my Eastern woodland style selfbow was shooting low 140s.

Now what's confusing me is occasionally my Redstag would shoot 150s, but then all of a sudden would shoot 165+ I even had one arrow go up to 186! And No, I was not changing my form or shots, I was trying to stay as consistent as possible.

I changed the battery in the chronograph to see if maybe that would change anything, but it didn't.

Has anybody else had this happen? Could it be a lighting issue? Or have my bows just got weaker?

[el greco]

I solved this random readings problem when I bought the light kit that goes with my chrony. Now I can shoot it indoors, night or day, and get consistent results. The only way to ho in my opinion.

If you want to get really confusing readings, put it under a tree on a sunny breezy day.  Those little flashes of sunlight will confuse them pretty good.

[McDave]

Ditto on the lights and shooting indoors.  I'm not sure my chrony is accurate, in an absolute sense; otherwise, why would they make thousand dollar chronys?  However, using the lights and shooting indoors, it does give good comparative readings that are consistent from one time to the next, so I can compare one bow against another, and see what effect changes in arrow weight have on speed.

[crazynate]

I've had similar inconsistent readings outdoors. Bought the light kit and I get way more consistent reads. I'm not a speed chaser either but do like comparing bows and arrows.

[monterey]

If I use mine outdoors on an overcast day it seems more consistent.

[RedStag5728]

Thanks for the responses, I'll have to invest in the light kit for it. Great suggestion!