Zulus Balistics calc.

[kenbro]

Hi.
Just thought I’d test out the Bal. Calculator on my Zulus though I don’t use it in the field.
At range this morning I fired a test shot (No calculator) at 50 yards, absolute bang on centre.
Moved to 200 yd range and fired these 3 shots. 1” low as they should be.
Then switch Bal. Calc. on and fired 3 more! Next pic. And they’re 2” too high!
I’d put 2900 fps in the Zulus when setting the calculator so I fired 10 rounds over the chrono before coming home, average speed was 2930, so not that far out.
I’ve checked all my inputs in the Zulus and they’re correct.
No idea why this is happening, have you?
Cheers, Ken.

 

[nun_hunter]

I had the same with Strelok and used the trying function to get it accurate. There isn't this function on the Zulus so I just tweaked the BC until I got it functioning correctly.

There are bound to be differences between what the manufacturers state and what happens with your own rifle.

 

[kenbro]

I had the same with Strelok and used the trying function to get it accurate. There isn't this function on the Zulus so I just tweaked the BC until I got it functioning correctly.

There are bound to be differences between what the manufacturers state and what happens with your own rifle.

I will try that.
If I get it shooting right at 200, would you think I should be okay at all ranges?
Thanks for input, Ken.

 

[sauer]

Define "all ranges"?
You'd be better putting out targets at ranges your happy to shoot at and drop chart it see if it does what says on the tin

Paul

 

[kenbro]

Define "all ranges"?
You'd be better putting out targets at ranges your happy to shoot at and drop chart it see if it does what says on the tin

Paul

I’ve previously done that Paul and it shoots pretty much where it should do between 50 and 200 in 50 yard increments, but, I just want to know if the Balistic calculator will do what it says on the tin.
Thanks, Ken.

 

[kenbro]

Would lowering the bullet BC in the Zulus lower the point of impact at 200 yards?
Ken.

 

[Jelen]

if you're shooting high at 200 you need to Increase the BC by small increments (0.05) 'till you're on POA.
Conversely if your POI is low, decrease BC.

 

[kenbro]

if you're shooting high at 200 you need to Increase the BC by small increments (0.05) 'till you're on POA.
I love the Zulus for small quarry. Once you've got it set up it takes all the guesswork out.

I thank you.
Ken.

 

[Foxyboy43]

This was from a certain chap who knows quite a bit about the Zulus….
“If you are missing at close range adjust the scope height number and if you are missing at long range adjust the ballistic coefficient number.
If you are missing low, reduce the ballistic coefficient number and if you are missing high, increase the ballistic coefficient number”.
You are welcome…

 

[nun_hunter]

I will try that.
If I get it shooting right at 200, would you think I should be okay at all ranges?
Thanks for input, Ken.

If it's accurate at 200 and beyond then it'll likely be accurate in-between but best to check. Strelok does this automatically (well at the press of a button) so when I transferred the same data from there to my Zulus I was initially confused as to why it wasn't as accurate at longer ranges. I had to drop the BC in the case of my 22lr.

 

[kenbro]

This was from a certain chap who knows quite a bit about the Zulus….
“If you are missing at close range adjust the scope height number and if you are missing at long range adjust the ballistic coefficient number.
If you are missing low, reduce the ballistic coefficient number and if you are missing high, increase the ballistic coefficient number”.
You are welcome…

I do wonder, if you input everything correctly why it fails..,
Ken.
Ps Must be those imponderables I’ve heard about.
You pay a couple of extra ££ for B Calc. you expect it to work!

 

[Smellydog]

if you're shooting high at 200 you need to Increase the BC by small increments (0.05) 'till you're on POA.
Conversely if your POI is low, decrease BC.

That's where I've gone wrong before

 

[Foxyboy43]

I do wonder, if you input everything correctly why it fails..,
Ken.
Ps Must be those imponderables I’ve heard about.
You pay a couple of extra ££ for B Calc. you expect it to work!

Hmmm.
Something not right there KB - when I first got mine it was not that accurate; then I chronoed my .222 - turned out my “remembered” velocity was 200 fps slower than the true figure so a quick data correction and now with a 100 yard zero mine has been spot on at foxes out to 315 yards and plates at 200, 300 and 400.

 

[kenbro]

Hmmm.
Something not right there KB - when I first got mine it was not that accurate; then I chronoed my .222 - turned out my “remembered” velocity was 200 fps slower than the true figure so a quick data correction and now with a 100 yard zero mine has been spot on at foxes out to 315 yards and plates at 200, 300 and 400.

I’d inputted 2900 for the triple with 52 grain bullets.
Over the chrono today it averages 2930 so I’ve changed that. Not that I can see 30 fps making much difference.
Thanks, Ken.

 

[Foxyboy43]

I’d inputted 2900 for the triple with 52 grain bullets.
Over the chrono today it averages 2930 so I’ve changed that. Not that I can see 30 fps making much difference.
Thanks, Ken.

Nope - 30 will make little odds - you may wish to adjust in higher increments?
MJ should be along in a moment or two….

 

[mealiejimmy]

You asked what's happening - well, what's happening is that the ballistic calculator is not giving you the results you want
If you want the ballistic calculator to give you the results you want then you'll have to change one or more of the ballistic data values you are using - even although the value(s) you enter does not agree with the real world
Ballistic coefficient generally does not have much effect on centrefire rounds (but it does have an effect on air rifle pellets)
I suggest you play with the muzzle velocity
If you shots are landing high then the ballistic calculator has calculated too much holdover and the rifle is pointing too high- i.e it thinks the muzzle velocity is lower than it actually is
So, increase the muzzle velocity in your ballistic data
Try steps of 50fps and see what the results are
You can fine tune the muzzle velocity far better than you can fine tune the ballistic coefficient

Cheers

Bruce

 

[kenbro]

You asked what's happening - well, what's happening is that the ballistic calculator is not giving you the results you want
If you want the ballistic calculator to give you the results you want then you'll have to change one or more of the ballistic data values you are using - even although the value(s) you enter does not agree with the real world
Ballistic coefficient generally does not have much effect on centrefire rounds (but it does have an effect on air rifle pellets)
I suggest you play with the muzzle velocity
If you shots are landing high then the ballistic calculator has calculated too much holdover and the rifle is pointing too high- i.e it thinks the muzzle velocity is lower than it actually is
So, increase the muzzle velocity in your ballistic data
Try steps of 50fps and see what the results are
You can fine tune the muzzle velocity far better than you can fine tune the ballistic coefficient

Cheers

Bruce

Simples….when you have the knowledge…
Thanks Bruce.
Ken.

 

[villaman]

same principle for rimfire , centrefire

 

[BenBhoy]

Did you get it sorted @kenbro ?

 

[Jelen]

I do wonder, if you input everything correctly why it fails..,
Ken.
Ps Must be those imponderables I’ve heard about.
You pay a couple of extra ££ for B Calc. you expect it to work!

GIGO. Garbage in, garbage out. But I was caught out last week. Friend wanted to buy my spare Zulus. Before we went to the range I manually input his data directly into the Zulus.
On the range we zeroed it at 100yds then used the LRF to check at 200yds. Miles out. I couldn't get it to work. Took it home and factory reset then used bluetooth to transfer the Ballistic Table to the scope. It worked perfectly after that. I still don't know what I did wrong in the first place .