Near zero focus and far zero focus calculation

[Doral]

On my 10M AP pistol, I am shooting, let's say, 500 ft/sec.

If the near zero focus is at 10M, where is my far zero focus?

What is the simple formula for calculating this?

[RobStubbs]

On my 10M AP pistol, I am shooting, let's say, 500 ft/sec.

If the near zero focus is at 10M, where is my far zero focus?

What is the simple formula for calculating this?

You've lost me, are you refering to visual focus ? You should be focusing on the foresight if that's what you're asking, i.e. close to where reading glasses would put you.

Rob.

[Guest]

In the 10 M AP pistol the near/far zero concept is irrelevant due to the short trajectory.

Anyway you can use the chaingun program to do the maths.
Regards,
Lorenzo

[Doral]

This is what I mean near zero and far zero.

http://www.ebr-inc.net/balistics_calcul ... round.html

Why would this be irrelevant for air pistol?

If 10M is near zero, where is the far zero?

[Pat McCoy]

If you are zeroed at 10m, that is the far zero. The near zero would be about half that distance.

[Spencer]

...Why would this be irrelevant for air pistol?...

wrong question - rather ask 'why would it be relevant'?

[derekm]

Try chairgun at http://www.chairgun.com/

[paw080]

quote="Doral"]On my 10M AP pistol, I am shooting, let's say, 500 ft/sec.

If the near zero focus is at 10M, where is my far zero focus?

What is the simple formula for calculating this?[/quote]

By Golly Doral, it looks like you don't get to have a far zero.
The pellet seems to just drop from the 10 meter zero.
Try this link... http://www.arld1.com/holdoverunderdonesteve.html

I used .6" for LOS
Again, beside curiosity, why do you want to know this? Is it because
you want to shoot AP Silhouette, or AP FT?
Good luck;
Tony

[Doral]

AP FT.

But I realized that there is no far zero according to your provided formula. There is no such thing as far zero for 10M AP / FT.

[Doral]

AP FT.

But I realized that there is no far zero according to your provided formula. There is no such thing as far zero for 10M AP / FT.

[paw080]

Hi Doral, I think you can push your zero farther out to ?? maybe 15-18yds
and see how much(estimate only) you'll have to hold over or under.
I wanted to try PFT with one my 10 meter AP's but here (CASA) I think
they are shooting out to 50 yds. I just cannot hope to hit anything with
open sights that far away. Here they just use the same FT targets as the
Open and Spring class air rifles. If the farthest target was 30 yds and has
a 2" kill zone, then open sight AP shooters have a chance. But, at 30yds,
the local kill zones are only 1" at the largest, and sometimes they are
1/2 at 25 yds. The AP's have to be scoped for me to compete. I've discovered
that most PFT shooters don't understand the concept of open sights; they
allow AP's equipped with red dots and front globe and rear peep sights to
shoot in the "Open Sight" class. Again, Best of Luck;

Tony G

[Doral]

I was hoping there is a far zero for that 1" FT hole at 25 yard, so I don't have to adjust between my 10M AP and 25 yard FT.

You are right about red dot should not be used for "Open sight" competition.

[tenex]

According to my calculations, my K2 (at 526 fps) is at it's peak trajectory between 9 and 10 meters. It's down hill in either direction. The good news is that I can shoot in my 9 meter basement without adjusting sights. I can also pretty much shoot at the NRA B2 slow fire target without sight adjustment at 50 feet (the smaller bull gives a little built in elevation with a 6:00 hold).

There is a free ballistic program available on the net, but I can't find it at the moment. You could use that to find the velocity that would put zeros at 10 and 25, but I suspect that the velocity might be unreasonably high.

Happy Thanksgiving,
Steve.