Chronograph Driving me Crazy

Sniper@123

Sniper@123

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Hi guys I worked out my chronograph it doesn't need to read pellet weight for it to give a reading
The reading
For this is
1575
1579
1586
1600
1574
1579. Please can someone give the FPS power for my hw100kt it's been driving me made then found out it doesn't need pellet weight to read output plus the airgun centre can't get on with it need your opinion please guys much appreciated regards SpM
 
What chrono is it?
It does need the weight to calculate the power.

.22 in the region of 600
.177. '. ". " 760
 
Something majorly wrong with those numbers. what pellet are you using?
An average .177 should be approx 750-770
An average .22 should be approx 550-570
 
Ok, here goes… you’re right, those numbers make no sense.

Chrono’s will normally display either feet per second (FPS) or metres per second, ones designed for the UK market will generally display FPS as we tend to use that in order to calculate muzzle energy using foot pound energy (FPE) as the unit for power.

To give you an idea of ‘normal’ numbers 750 FPS would equal 226 metres per second and with an 8.4 grain (gr) pellet work out at 10.49fpe.

1500 fps with the same 8.4gr pellet would be 41.98fpe and if your chrono was displaying metres per second then 1500 = 452fpe!

Hence I agree those numbers make no sense 🤷🏻‍♂️
 
Spud gun said:
What chrono is it?
It does need the weight to calculate the power.

.22 in the region of 600
.177. '. ". " 760
Click to expand...
A Ali express it says online in the instructions online no need for pellet weight one pellet weight 15.89gr .22
Readings that shot back are
157.5
157.9
158.6
160.0
157.4
157.9 these are results either FPE or FPS this shit chronograph what a waste of money
 
Sniper@123 said:
A Ali express it says online in the instructions online no need for pellet weight one pellet weight 15.89gr .22
Readings that shot back are
157.5
157.9
158.6
160.0
157.4
157.9 these are results either FPE or FPS this shit chronograph what a waste of money
Click to expand...
You don’t need the pellet weight to measure the speed which is all a chrono measures, decent ones then calculate power which requires the pellet weight.

Assuming it’s giving you metres per second as it’s from Ali Express then 160 metres per second with a 15.89gr pellet = 9.73fpe
 
Sniper@123 said:
A Ali express it says online in the instructions online no need for pellet weight one pellet weight 15.89gr .22
Readings that shot back are
157.5
157.9
158.6
160.0
157.4
157.9 these are results either FPE or FPS this shit chronograph what a waste of money
Click to expand...
The readings are in MPS

158.22 MPS average and assuming you're still using 15.89 gn Exacts, your FPE is 9.51

Your other thread : https://airgunforums.co.uk/threads/what-power-are-these-readings.197068/#post-3093175
 
Last edited:
It is not a shit chronograph, you have just not bothered to procure and read the manual thoroughly... 🤷🏻‍♂️
Three threads on the same subject when the short answer to your problem is just RTFM!
Whatever chronograph you get will need to be set-up properly.

150.0m/s = 492.12ft/s
That should be a fair indicator of what setting you are on.
A simple app like AirgunToolkit from arpc.uk will completement your readings easily.

You may want to try this type to make your life easier but it will still require reading the manual and set-up for pellets.
-4740497922092834964.webp
 
That means it's 12.FT/S is that correct my friend what other cheap but good chronograph is out there when I don't need to put in pellet weight I would like one just already setup plug and play you know what I mean. Thanks for the help to much appreciated
 
Sniper@123 said:
That means it's 12.FT/S is that correct my friend what other cheap but good chronograph is out there when I don't need to put in pellet weight I would like one just already setup plug and play you know what I mean. Thanks for the help to much appreciated
Click to expand...
putting in the pellet weight is purely for if you have a chrono that does the speed to power conversion for you, you don't NEED that but it saves you some time if that's the thing you're interested in - otherwise you can do it with any one of the hundreds of calculators online like https://www.omnicalculator.com/physics/bullet-energy (which supports m/s too)

your chrono is JUST giving you the speed that a projectile went through it, in meters per second (but from your other post it looks like it can do either meters or feet)

edit: make sure you set the units correctly if you use that site

1778075353696.webp
 
Are there chronos that don't require pellet weight to calculate velocity?? Never come across one, my advice would be if your totally unfamiliar with how and why chronos work then buy a decent one to start with and save yourself the hassle.
 
Tricky-Dicky said:
Are there chronos that don't require pellet weight to calculate velocity?? Never come across one, my advice would be if your totally unfamiliar with how and why chronos work then buy a decent one to start with and save yourself the hassle.
Click to expand...
Some of the cheap chronos just read the pellet velocity, others have the capability of entering the pellet weight for FPE readout
 
Sniper@123 said:
That means it's 12.FT/S is that correct my friend what other cheap but good chronograph is out there when I don't need to put in pellet weight I would like one just already setup plug and play you know what I mean. Thanks for the help to much appreciated
Click to expand...
No it doesn’t, read the reply you were given!
@JacquesC explained, the chrony reads in metres and you told us that reading was 150 m/s. That converted to 492.12 feet/ second, as was explained- nothing to do with .12ft/s.

To get the power. And making it easy as I’ll do it for metres as your chrony gives that, the equation is
Power (ftlb) =. (Pellet weight) x (pellet speed in metres /second)
Divided by 41829.7.

That will then tell you power output and no converting to feet required.
 
That hurts said:
Some of the cheap chronos just read the pellet velocity, others have the capability of entering the pellet weight for FPE readout
Click to expand...

Randomone said:
All of them don't require weight to calculate velocity. Shrug tt They will all display it, they require the weight to calculate the muzzle energy from the velocity.
Click to expand...
Sorry should have put energy not velocity doh! Too used to using proper chronos.
 
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