10 yard zero and figuring out shorter POIs?

[Eric_L]

If you zeroed at 25, you’ll be ok at 35 without any holdover.

https://www.recoilweb.com/wp-content...ol_Zero_02.jpg

Very nice find. This discussion reminds me of incessant discussions years ago about AR zero at 40/240 (I think that’s what it was). Basically, if you understand this graph, then shoot your gun at all distances you are interested in, you’ll understand what YOUR gun does with that load in your hands.

[RJ]

The diagram @RJ posted has the bullet traveling straight. It doesn't. It arcs above your line of sight.

Ja I need to model that sometime.

So we were having some whiteboard discussions at a break during a System Requirements Review with a bunch of Royal Artillery gunners on a simulator we were building for the AS90 (self propelled 155mm howitzer) a few years ago. We got them to describe the ballistics calculations they were using. One of them casually mentioned that one of the things they take into account was the fact that the earth rotates during time of flight (range of the AS90 is measured in km.) It gave me an appreciation of how detailed some of this stuff can be.

[G19Fan]

It just occurred to me that’s probably why I never seem to manage to hit those 35 yard targets on the longer field stages I’ve been on. I aimed high, assuming bullet drop, but maybe I should have aimed lower to account for a 25 yard zero. Did I say that right?

A 25 yard zero.no holdover needed out to about 45 ish

[Clusterfrack]

Ja I need to model that sometime.

https://www.hornady.com/team-hornady...lators/#!/4dof

[rayrevolver]

One of them casually mentioned that one of the things they take into account was the fact that the earth rotates during time of flight (range of the AS90 is measured in km.) It gave me an appreciation of how detailed some of this stuff can be.

Coriolis Effect. I learned about it from a video game...was it the Call Of Duty MW sniper level with a Barret?

It's a thing with longe range rifle shooting.

https://www.lapua.com/ballistics-app...riolis-effect/

[BN]

Don't forget spin drift. I need to account for it with long range 22LR.

[Jim Watson]

Everybody, click this link @Clusterfrack gave you. Notice that if you have a close zero, that you will be shooting over your target at distance. Think about throwing a football. It arcs above your line of sight, just as your bullet arcs above your line of sight. The diagram @RJ posted has the bullet traveling straight. It doesn't. It arcs above your line of sight.

1. If it were drawn to scale, you probably could not see the curvature.

2. Look at Clustefrack's graph. If you zero at 25 yards, the line of flight is never above the line of sight, it comes up to it and drops off.
If you zero at 50 yards, that is the "second crossing" so your short range zero could be at 12 yards. Look at the scale, the line of flight is only half an inch above the line of sight about 35 yards and half an inch below at 55 yards. Don't worry about holding over or under at ordinary pistol ranges. If you are hitting low at 30 yards with a well zeroed gun, you are flinching.

3. ETA, looking at the vertical scale on that graph, if you are zeroed at 10, 25 or 50 yards, you will be within an inch of the line of sight above or below for over 50 yards.

[Clusterfrack]

Coriolis Effect. I learned about it from a video game...was it the Call Of Duty MW sniper level with a Barret?

It's a thing with longe range rifle shooting.

https://www.lapua.com/ballistics-app...riolis-effect/

LOL! This really is Pistol-Forum...

2 hits on the 1 Mile target. Very satisfying.