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Main Boards => PowWow => Topic started by: Beepy on April 30, 2008, 09:41:00 PM

Title: Chrony Expectations
Post by: Beepy on April 30, 2008, 09:41:00 PM
You guys might have noticed in my few posts that I have gotten back into trad archery.  Before I was using an inexpensive PSE Impala.  A few months ago I picked up a new Martin Hunter, and ran it through the Chrony at work (it had been recently calibrated) and I was getting 235 fps with 450gr and my arrows are 600gr running 205 fps.  I recently picked up one of those cheaper Verna longbows and just ran it through the chrony today.  I was getting 185 fps with the 450's and 175-8 fps with the 600gr's.  Should I expect such a let off with the Martin?  I lost 30fps going between the arrows but the newer longbow only lost 10fps.  Is this normal\\


Oh and the Marin is 55# @28 and the Verna is 50# @28, my draw is 31.5 inches....
Title: Re: Chrony Expectations
Post by: j yenney on April 30, 2008, 09:57:00 PM
Your new chrony sounds alot more truthful. I shoot a Kota kill-um 57 pds with a 425 gr arrow and I get some where around the 200 fps.(it's been a while so I think that is what it's around).However it's quite a bit faster that my 55 pd bear SK. So long as you shoot it acurate, that's all that matters. I limit myself to 25 yd shots while hunting anyway. Your shooting plenty fast enough.
Title: Re: Chrony Expectations
Post by: aromakr on April 30, 2008, 10:46:00 PM
Beepy:
I think your receintly calibrated chrony needs re calibrating. NO WAY!! 600grs with a 55# bow is almost 11 grains per pound of bow weight, and 205 fps don't think so.
Bob
Title: Re: Chrony Expectations
Post by: Beepy on April 30, 2008, 11:36:00 PM
measured at my draw length thought the martin is pulling #70 and the Verna #68
Title: Re: Chrony Expectations
Post by: NDTerminator on May 01, 2008, 05:49:00 AM
Your Martin readings sound much higher than reasonable and your Verna sounds low with the 450s and if anything, high with the 600's.

I noticed you said you were shooting at work, so presumably you were shooting indoors?  I've used Chronys for better than 20 years and find that every one I've had gave erronous readings indoors, particularly under flourescent lighting.

Outdoors under bright sunlight they where/are good to go...
Title: Re: Chrony Expectations
Post by: smilinicon on May 01, 2008, 06:09:00 AM
actually, chronos show errors in the bright sun. You want overcast or diffused light for the best results when outdoors.
Title: Re: Chrony Expectations
Post by: R H Clark on May 01, 2008, 12:20:00 PM
With the lighter arrows you are only shooting 6.4 gpp and the heavier are 8.5 gpp.You might get by with the heavier arrows though at your draw ,that is still a lot of stress on that bow.With 6.4 at your draw, IMHO you will reduce the life of that bow.

I like light fast arrows also but I shoot metal risers and limbs designed for it.