Author Topic: first time thru a chronograph  (Read 851 times)

Offline Keith Wolfe

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first time thru a chronograph
« on: May 29, 2016, 10:37:00 PM »
I never thought about it before but when I heard well made bows shoot 100fps+ poundage I decided to get one to check my efficiency. Here's the verdict. My 50# I just made was consistent 146-147fps. The 40# is 138fps and the 30# was 128fps. Looks like I'm just shy of a a+ but I felt good about being close. Could the cheap Dacron string material from 3rivers at 16 strands be the reason? Would like to be where I'm supposed to be for my clients. By the way. My PSE 45# recurve was consistent at 160fps with silencers and camp tape on the back. They do a good job! Any advice would be appreciated.

Offline chackworth3

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Re: first time thru a chronograph
« Reply #1 on: May 29, 2016, 11:10:00 PM »
How heavy are your arrows?

Offline Wolftrail

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Re: first time thru a chronograph
« Reply #2 on: May 29, 2016, 11:56:00 PM »
I'am shooting 600 carbon arrows 30" length 125g tips from my 45 pound PSE.   You must be close to that.

Offline mikkekeswick

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Re: first time thru a chronograph
« Reply #3 on: May 30, 2016, 02:10:00 AM »
Yes ditch the dacron and get any one of the fastflight masterials you will see a big increae in performance.
A string needs to be bow weight x 4 to be safe.
A 50# bow = 200# string.
Dacron tests at about 35# breaking strain. So 200/35 = 5.7 so 6 strands of dacron is safe.
Fastflight strands tend to break at about 65 - 70# so your 50# bow actually only need 4 strands to be safe.....
Now you can see that most bought strings are way, way overbuilt....like towing a car overbuilt!
If you want better performance make your own strings and don't go mad with the amount of strands.
Thinner strings are noisier but faster.
thicker strings are more quiet but slower.

Offline Keith Wolfe

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Re: first time thru a chronograph
« Reply #4 on: May 30, 2016, 08:56:00 AM »
Arrows 8gpi 125 tips 31 inches if I have my terminology correct.

Offline Keith Wolfe

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Re: first time thru a chronograph
« Reply #5 on: May 30, 2016, 08:58:00 AM »
Oh and was wondering if you do double layer off serving with the smaller diameter string? Thanks

Offline Eric Krewson

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Re: first time thru a chronograph
« Reply #6 on: May 30, 2016, 09:16:00 AM »
Draw length has a lot to do with speed as well. The standard poundage +100 fps is at a 28" draw, draw less, expect less.

Pretty sure DF-97 breaks at 125# per strand. I still use 12 strands because I found really skinny strings to be harsh to shoot. 12 strands and .025 serving fits my arrow nocks perfectly as well.

If you go real skinny on your strings it would be a good idea to pad your string nocks with 4 extra strands of B-50 to take up some of the shock.

Offline Keith Wolfe

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Re: first time thru a chronograph
« Reply #7 on: May 30, 2016, 02:18:00 PM »
Thanks. My draw length a little over 27" so we'll blame it on that!

Offline TradBowyer

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Re: first time thru a chronograph
« Reply #8 on: June 15, 2016, 01:33:00 PM »
without knowing what draw length you were shooting, arrow weight and string material its hard to comment. Basically, a standardized test is a 28" draw, 9gpp arrow (450 grain for a 50# bow) and a 16 strand FF string. Using this criteria, the majority of recurves are falling into the 190 fps class, R/D longbows 180s (some in the 190s),and straight limb longbows in the 160s. putting on a B50 string will lower these numbers around 10fps average.

Offline Wolftrail

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Re: first time thru a chronograph
« Reply #9 on: June 15, 2016, 03:16:00 PM »
Quote
Originally posted by mikkekeswick:
Yes ditch the dacron and get any one of the fastflight masterials you will see a big increae in performance.
A string needs to be bow weight x 4 to be safe.
A 50# bow = 200# string.
Dacron tests at about 35# breaking strain. So 200/35 = 5.7 so 6 strands of dacron is safe.
Fastflight strands tend to break at about 65 - 70# so your 50# bow actually only need 4 strands to be safe.....
Now you can see that most bought strings are way, way overbuilt....like towing a car overbuilt!
If you want better performance make your own strings and don't go mad with the amount of strands.
Thinner strings are noisier but faster.
thicker strings are more quiet but slower.
I'm using endless loop B-50 on my Recurve no problems.  12 or 14 strands whatever so what. No Fuss No muss Guss...!

Offline mikkekeswick

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Re: first time thru a chronograph
« Reply #10 on: June 16, 2016, 03:12:00 AM »
Wolftrail - I think you missed the point....I was merely saying that most modern strings are massively overbuilt - IF you want more arrow speed it is perfectly safe to make a string with less strands than 'normal'.
Please explain why you think I was suggesting that a 'normal' thickness string would give you 'problems'???

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