ballistic calculators for long range airgun shooting

[JZetec]

I am sure long range air gunners can help me with this. I used a number of different ballistic calculators and found that nearly all of them for the same ammo and conditions give different data, confused which one to trust. And after printing few tables I did some test shooting and result I got do not match with any BC, very confusing.

Do you guys use BC for drop calculations or finding out hold over / under by shooting at different distances and making your own tables?

ChairGun is supposed to be amazing. I witnessed a gent using it the other night and he was shooting really well.

Worth a look, and is available on smartphones (ios/android).

Free as well from memory..

[ACQPL]

I have found chairgun to be a very useful tool. It is indeed free !
After trying a few distances with the same zero on my scope, as was in chair-gun - the POI calculation seemed pretty spot on (couldn't go over 25m though)

[MTA123]

I've tried chairgun on the PC and it worked fairly well, but Im using Strelok now which also matches reality pretty well and has better interface for small android devices.

[walrus1#]

using any method for calculating BC will still only be a rough guide at best!! as the same ammo from a different barrel will give a different result.The calculations of the manufacturers as printed in Chairgun are an average only,and never exact.These will however get you as near as you really need to be in the real world.Chairgun will get you 95% of the way and you simply fine tune for your own shooting, by trial and error.

[MTA123]

When refined by using muzzle velocity data it gets pretty close - definitely a useful learning tool if nothing else.

[svds]

Thank you guys for explaining, going to have few shooting sessions soon to test which BC gives closest data for my guns, but pretty sure that walrus1# is right - "BC will still only be a rough guide at best", will see.

[PaulJC]

Define long distance?

For the most accurate chairgun setup...

Weigh some pellets, collect a batch of the same weight to use for your crono testing.

Chrono your gun at the muzzle and again at a set distance with your weighed pellets.

These 2 will be able to create an accurate BC for your pellet and the correct muzzle velocity for your gun.

Then an accurate zero is needed, like spot on, gun clamp, bench and indoor range till you can pellet on pellet at your zero distance.

Then you need the correct scope to barrel measurement, most people do this wrong by just measuring between the centreline of the barrel and the centreline of the scope, that IS NOT how it should be done, it should be measured at the end of the barrel and be the distance between where the crosshairs project on an item at the end of the barrel and the centre of the barrel (note: 'barrel' not moderator), full instructions are in the manual...

Then you measure and input the distance between the end of the barrel and the reticle (centre turret) and input that, then you have chairgun set up as close as possible...

Then the wind blows, the temperature changes, your pellet weight isn't spot on or your rifle is having a bad day and it all goes to shit anyway lol