How accurate is EXBAL?

[Ernie]

I use the Kestrel 4000.

 

[JOSE A. MARINE]

would like to use a casio pathfinder watch to give me the baro, temp and altitude, would that work?

I dont have a kestrel but have a caldwell windmeter that also has temp.

which palm/handheld pc would work best?


thanks
Joe

 

[kidcoltoutlaw]

If you velocity changes due to a temp. change does the program allow for it ? Or do I re chronograph my loads in the new temp ?

Thanks,Keith

 

[Ernie]

yes

 

[kidcoltoutlaw]

So I leave the velocity the same and just change the temp, right ? With my 338 RUM it works great but I'm having problems with my 308 at 1115 yards. The program is 3 MOA off. Sierra says it might be bullet yaw because that is a long way for a 190 MK at 2488 velocity,

Thanks,Keith

 

[Ernie]

Leave your MV the same.
When conditions change, change the conditions in Exbal: Alt, temp baro pressure, humidity.
Is the MOA spot on in all of the other distances?

 

[kidcoltoutlaw]

This is crazy the scope lies. I did a test today at 93 yards for a zero because the target holder was not at 100 yd. Came up 30 MOA it moved the POI 31.5 inches. Did it again with 35 MOA it moved POI 37.5.

If I did the match right the clicks are .2837 MOA ?

At 780 yards 11 degrees up hill I put 23 MOA not corrected up but what the scope says and I was about 1.5 MOA low so I need 24.5 for hits in the center. At 780 yards.
I ranged the longshot again today after sundown and got 1036 meters over and over.

Thats 1133 yards I might be pushing the limit for a 308 at 2488 fps ??
It just makes me crazy that I need more than the program says and the scope erro is giving me some MOA to boot.

I have Nightforce on my other guns

308 Winchester
190 MK BC 533
Velocity 2488
scope 2.75 high it is a Armalite AR-10A4
elevation 2700 feet
Scope is a Leupold 4.5-14x50 one inch not the long range one
EGW 20 MOA mount

I reckon the big ??? is will a Kestrel hand held weather station make me more accurate. BP plays a big factor as long as the scope is right.

 

[Ernie]

30 MOA=31.61 inches

 

[kidcoltoutlaw]

I wa at 93 yards not 100 so that lessens the measurement by 7% is that right ? Over all it looks like I'm wrong and the scope is right, correct ?

Thanks,Keith

 

[Ernie]

MOA/Minute of Angle is 1.047 inches per 100 yards.
As far as I can tell the scope adjustment is doing what it is supposed to do.

A lot of people when discussing MOA use what is called "Shooter's MOA" which rounds down MOA to 1" per 100 yards:
1 MOA= 1" @ 100, 1 MOA=3" at 300 yards, 1 MOA=5" at 500 yards, 1 MOA=10" at 1000 yards, etc.

 

[kidcoltoutlaw]

The 308 Winchester At a normal range of 779 yards it is very close.

Is 1036 meters to far for a 190 Sierra MK at 2488 velocity at the muzzle ?

Will the kestrel be a big help ?

 

[Ernie]

When you start approaching sub sonic speeds it is called transonic, and there tends to be accuracy issues at times.
Plus you can easily have some in -accuracy with your chronograph as well, which the further you go the more off it will be.
What it comes down to is this:
Chronographs and ballistic software are going to get you close.
But, you build your drop chart off repeated shooting at distance to confirm what your drops actually are.

 

[kidcoltoutlaw]

My setup is Oehler 35P it has double screens checks velocity twice so I pretty sure it is right. I think the distance is to far for the 308 at 1036 meters it is close to the transonic edge. Happy to be wrong about my scope being off.

As far as shooting and getting the DOPE I'm shooting 11 degrees up hill. I have a ACI and use it but now they sell something to zero it. When I bought mine they did not. I don't think a few degrees up or down is a big deal unless the range is 1000 yd plus then anything can matter ?


Thanks,Keith

 

[Ernie]

Keith,
Sounds like you should have a pretty accurate chrono data with the 35P. The further apart the screens are the more accurate it will be-Mine are 4 feet.
Shoot the distances you want!
Have fun, learn, and let your shooting determine you and your weapon's limits.
Another variable is wind, as wind can effect you vertically as well depending on terrain and direction.
Shooting out to 700 yards seems to have fewer gremlins, but once you go past that distance they seem to multiply proportionally every 100 yards