Alpex 4k bc calculator help

[Sniper308]

with the weather being good I decided to test out the alpex at 50 yard intervals out to 350yards.
The drop doesn’t quite work out correctly.
All figures are typed in correctly etc.
At 350 yards It’s dropping around 2.5” low
At 300 yards it’s dropping around 2” low
At 250 yards it’s dropping around 0.5” low
150 and 200 seems to be pretty spot on, and it’s zero is 100.
What do I need to adjust to get them lined up correctly?
It’s the .290bc 53g vmax bullet travelling at 3340 fps

 

[mealiejimmy]

Reduce the value you have used for the muzzle velocity
Try steps of 20fps and see how you get on
Don't muck around with BC or scope height

Cheers

Bruce

 

[BE Precision]

zero it at 150, it will reduce the error at range. and then fine tune it by playing with the velocity figures.

 

[Dari]

What do I need to adjust to get them lined up correctly?
It’s the .290bc 53g vmax bullet travelling at 3340 fps

Did you measured velocity with chronograph or you just trust values vritten on the box?

 

[Donkey Basher]

Mines about to be sent off for them to sort out it switching off LRF & ballistic app whilst it’s turned off…

When it comes back it’s going to get zeroed at 200 yards which is what my glass scopes are zeroed at & what I’m used to being able to just ‘point & shoot’. Then I’ll be doing some real world stuff with it to adjust the MV to get drops correct, as @mealiejimmy mentions. Hopefully then I won’t experience the various low shots I’ve had this winter.

 

[User00057]

In my experience every factory boxed load FPS is shy from what is written on the box.
Obviously if you have Chronograph them then ideal.

 

[JockStalk]

Such a big improvement these ballistic calculators

 

[Sakoodin1]

with the weather being good I decided to test out the alpex at 50 yard intervals out to 350yards.
The drop doesn’t quite work out correctly.
All figures are typed in correctly etc.
At 350 yards It’s dropping around 2.5” low
At 300 yards it’s dropping around 2” low
At 250 yards it’s dropping around 0.5” low
150 and 200 seems to be pretty spot on, and it’s zero is 100.
What do I need to adjust to get them lined up correctly?
It’s the .290bc 53g vmax bullet travelling at 3340 fps

What calibre do you shoot?

 

[Sniper308]

It’s home loads, .223 is giving 3340 fps with the 53g vmax bullets.
Seriously happy with the scope, just needs fine tuning that’s all. Here’s a few groups, well within 1 moa!

 

[griff]

Forget the chrony, zero at whatever range suits, shoot it at whatever is your max range without using the the Ballistic Calculator, measure the drop and then reverse engineer your calculations, in other words play with the velocity until it gives you the drop you require. Your BC will change with your velocity, so you need to calculate the bc roughly for the given velocity over the range you are shooting then enter that into the Alpex. If you use Berger Ballistics then you will be able to adjust everything you need.

 

[Lavos]

It’s home loads, .223 is giving 3340 fps with the 53g vmax bullets.
Seriously happy with the scope, just needs fine tuning that’s all. Here’s a few groups, well within 1 moa!

How did you get on with this? have you manged to get it all to work?

 

[Sniper308]

How did you get on with this? have you manged to get it all to work?

Yes works an absolute treat! Tested out to 350 yards.