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All Springer/NP/PCP Air Gun Discussion General => Air Guns And Related Accessories Review Gates => Topic started by: match66 on October 14, 2024, 12:51:18 PM

Title: Help with chronograph joules to ft-lb
Post by: match66 on October 14, 2024, 12:51:18 PM

I have an Amazon Ballistic SC2000 chronograph, and it reads in joules. I go through the menu and set it for joules. I am using JSB RS 13.43 gr pellets. I put in the pellet weight 13.4 and hit the set button.

I am shooting a Diana Chaser with rifle barrel in .22 and get joule readings of 196.6 +/- I then use a Jules calculator to convert into foot pounds. And I am getting a number of 145.00472 ft-lb.

What am I doing wrong here?

Thank you :D

Title: Re: Help with chronograph joules to ft-lb
Post by: huntr on October 14, 2024, 01:14:34 PM

Sounds like your reading is incorrect, because the number you calculated is correct. Could you be seeing Meters per second, not joules?

https://www.unitconverters.net/energy/joule-to-foot-pound.htm

Title: Re: Help with chronograph joules to ft-lb
Post by: match66 on October 14, 2024, 01:16:15 PM

I found a video that shows a guy explaining how to use this chronograph.

I am entering grains and need to be entering grams. I was entering the pellet weight of 13.4 need to enter that weight in grams which is .87

I will try this later and see  ;)

Title: Re: Help with chronograph joules to ft-lb
Post by: Roadworthy on October 14, 2024, 01:36:33 PM

The Amazon description indicates it can read in feet or meters per second.  You need the speed from the chronograph and the pellet weight to calculate energy in joules or fpe.  It does indicate the chronograph can show energy in joules but your number looks more like a velocity than energy.

Title: Re: Help with chronograph joules to ft-lb
Post by: lefteyeshot on October 14, 2024, 05:11:27 PM

1 joule = 0.737563 fpe

1 fpe = 1.35582 joules

Title: Re: Help with chronograph joules to ft-lb
Post by: happymecanic on October 14, 2024, 06:56:46 PM

Quote from: match66 on October 14, 2024, 12:51:18 PM

I have an Amazon Ballistic SC2000 chronograph, and it reads in joules. I go through the menu and set it for joules. I am using JSB RS 13.43 gr pellets. I put in the pellet weight 13.4 and hit the set button.

I am shooting a Diana Chaser with rifle barrel in .22 and get joule readings of 196.6 +/- I then use a Jules calculator to convert into foot pounds. And I am getting a number of 145.00472 ft-lb.

What am I doing wrong here?

Thank you :D

I believe you entered the pellet weight wrongly. Your chrono seems to work in metric, so the pellet weight you entered (13.4) was actually acounted for in grams by the chrono. Convert 13.4 grains in grams and retry with the new pellet weight (0.87 grams).

And here's a good converter I use: https://www.pyramydair.com/airgun-resources/widgets/convert.php

Title: Re: Help with chronograph joules to ft-lb
Post by: match66 on October 14, 2024, 07:01:19 PM

That is exactly what I did wrong. Thank you GTA members for your replies  ;D