cheap chrono' cheap pocket scales

[cringe]

Hi, I treated myself, for xmas I now have a Chinese chrono & a drug dealers pocket scales, can anybody out there inform me the best way in simple terms, how do I measure velocity & power etc ? [this might be on an older thread?] kind regards Al.

[Jesim1]

Hi, I treated myself, for xmas I now have a Chinese chrono & a drug dealers pocket scales, can anybody out there inform me the best way in simple terms, how do I measure velocity & power etc ? [this might be on an older thread?] kind regards Al.

Hi Al

Without sounding uppity you need to read your chrono instructions on how to operate it as they are all different, but a few basics to ensure are:

1. Make sure it's set to units we use - so typically FPS/FPE/gn or your readings will be meaningless

2. Ensure consistency, you must shoot through the exact same way/distance/angle every time or your readings will be false

3. Don't shoot the chrono! Get it aligned and have a good backstop of open area behind it.

Pellets out the tin are fine for just casual checking of power, but if you weight ten pellets to within 0.1gn then do a 10 shot string then this is far more accurate and usable data.

And remember, most pellets will perform differently in most guns, it's common for you get to different power readings with different pellets, even the same pellets of different batches.

Typically lighter pellets perform better power wise in a springer, and heavier pellets perform better power wise in a PCP, but not always I use AA Express for springers and JSB heavies for PCPs to make sure I stay legal

[Ed51]

Try Airgun Calc from the app store

[Neil54]

If your chronograph is anything like mine it will read in metres per second and cannot be changed.
There plenty of online calculators where you input speed and weight and they tell you power.

At 670 fps ( or 204 mps) weight in grains = ft/lbs

[Biker_Bob]

If it reads in metres per second as most of the cheapie Chinese ones do, the formula is:

velocity x velocity x weight x 10.76 / 450240

for feet per second its:

velocity x velocity x weight / 450240

In both of those the pellet weight is in grains, to convert to grains from grams it's:

1 gram = 15.4324 grains

If you find that your scales don't give sufficient resolution then weigh 10 or 100 pellets at once and divide the reported weight appropriately to get the weight of one pellet.

[angrybear]

As an alternative many RFD sites have a converter, I usually use TBT's at .com it's at the bottom of the dropdown list for videos.

Oh it seems his site name is blocked