Velocity v range queery

[trajectory]

Hi,
Has anyone got a link to a previous thread or a formula for calculating theoretical pellet velocity at different ranges using a known muzzle velocity & pellet style please?
Thanks, Rod

[eyebull]

Use Chairgun, available on the Hawke website.

[ballisticboy]

There is no such thing due to the complexity of the calculus. The nearest you can get will be the standard flat fire equations which will workish over short ranges for lower speeds but rely on a constant Cd. Particularly for .177 pellets and for longer ranges in any calibre the constant Cd assumption is not valid.
As said earlier the simplest way is to use Chairgun.

[trajectory]

Thanks folks

[Phil Russell]

There have been some real life results reported recently in the airgun magazines.
Cheers, Phil

[ballisticboy]

There have been some real life results reported recently in the airgun magazines.
Cheers, Phil

The trouble with real life results is that you do not know the conditions under which the real life results were obtained. For example, was it a hot day or a cold day, was the pressure high or low, was there a wind blowing and at what speed and in what direction? All the above can make a significant difference to the results and make comparisons between tests meaningless unless corrections are applied and full analysis carried out, which brings us back to trajectory modelling which is the only way to rigidly control the conditions and make valid comparisons.

[Wilderbeest]

Giles on the AGGS, did a pellet caliber x velocity test which gave some very surprising and interesting results .
Worth a watch.

[airgunnut]

There is no such thing due to the complexity of the calculus. The nearest you can get will be the standard flat fire equations which will workish over short ranges for lower speeds but rely on a constant Cd. Particularly for .177 pellets and for longer ranges in any calibre the constant Cd assumption is not valid.
As said earlier the simplest way is to use Chairgun.

what ballistic boy said

there are a million and one things that can affect pellet velocity in flight
wind speed
wind direction
temperature
humidity
angle of shot (shooting up or down hill)
(these are just the common ones)

[angrybear]

Hi,
Has anyone got a link to a previous thread or a formula for calculating theoretical pellet velocity at different ranges using a known muzzle velocity & pellet style please?
Thanks, Rod

How about just placing a chrono at range x & shooting through it

[nimrod177]

How about just placing a chrono at range x & shooting through it

Only reliable calculation i got from shooting through my chrony was a depleted bank balance!

[trajectory]

Ballistics are indeed complex & dependant on many factors. In terms of practical testing with a chronograph outside it's just too cold, wet,& windy at the moment so the theoretical route seemed a possible alternative in the meantime, even if it might not provide an absolute answer.

[angrybear]

Only reliable calculation i got from shooting through my chrony was a depleted bank balance!

Yes, I know that feeling but learned the lesson "fit a shield if using down range"

OP, chairgun will get you "ballpark" figures.

[GPConway]

Yes, I know that feeling but learned the lesson "fit a shield if using down range"

OP, chairgun will get you "ballpark" figures.

Albeit a very small ballpark if you enter accurate data.

George