Zeroing longer ranges on shorter ranges

scubadog

Well-Known Member
So I am about to go and zero my (new to me) sako 75 .308 and Zeiss conquest scope with ballistic turrets.
I have access to a 100 meter indoor range.

My question is this.
I plan to zero my scope at 100 meters and then adjust my ballistic turret to display 0 at 100 meters.
Is it possible to use a ballistic calculator to work out the theoretical drop at say 300 meters (lets say -10cm for argument) and then mark a +10cm point on the target and adjust the ballistic turret until I hit the +10cm target so that I can record a rough point on the turrets that will be somewhere near zero at 300 meters?

I appreciate nothing is better than actually testing at various ranges though will this get me some where near to where I need to be?
 
I'm not sure I see the point of what you are attempting to do with a stalking rifle. Surely you can just set the POI at 100 yds to be 1 inch high and go off and stalk deer? Just ignore the ballistic turret stuff for stalking.

Regards

JCS
 
With my 308 I'm 2 inches high at 100 yards, which puts me about right on at 200 yards and about 9 - 10 inches low at 300 yards. That might help give you some idea of the sort of ballpark figures you are looking at.

You could use a ballistic calculator to work out how high you'd need to be at 100 to be dead on at 300 and then set your turret using this figure, as you suggest, by aiming at the calculated "300m" point on the target at 100m.

However, the big problem with this is that the calculated values will not be exactly what you will see in practise. So, it would probably be near enough to get you started and on the paper at 300 but in the end you are going to have to shoot at 300 to be sure.
 
Thank you.
That is exactly the help I was after.
I intend to use this rifle for both stalking and for days on the range.
Hence why I was hoping to be able to find the aim point for some longer range stuff to get me on the paper.

Private fraser - I cant remember what the app was called, I can let you know later.
 
Thank you.
That is exactly the help I was after.
I intend to use this rifle for both stalking and for days on the range...

Following up on my earlier comment. Where I am at just now is one rifle and two scopes. I have a rail on my Rem 260 and use a Swarovski for stalking and a March scope for range work. This approach worked well last year when I was using a NightForce borrowed from another Forum member for range work.

Regards

JCS
 
It all sounds a bit odd to me.. Your ballistic turrets will have increments on them, either 1cm/100m or 1/4 MOA @ 100yds? So, you dont need to mark your turrets etc, either make yourself a drop chart or use a ballistic calculator app on the day? Also, 10cm drop at 300m isnt the same as aiming 10cm high at 100m. You'd only have to aim 3.34cm high at 100m. I think if you try to do what you said in your OP, you'll disappear up your own ar*e! :)

Also, most ballistics calculators are pretty accurate, certainly sub 600m, but it boils down to the cliche of bull**** in bull**** out. So i would recommend getting a good average speed from your rounds and the type,make, weight of bullet then plug it into the app. This will give you a good starting point, but you'll probably have to fine tune the figures it gives you. Once you know your actual drop at range, then make your drop chart.

Please forgive me if ive missed the point completely?

FFM
 
Yea I think you have missed the point to be honest.

I appreciate that a 10cm drop is not 10cm high at 100meters.
What I am trying to do is find how high the trajectory needs to be at 100 meters to be on target at further ranges so that I can get a rough idea of where I need to be on my turrets.

I would like to mark my turrets so I can just turn the turrets to the "mark" for whatever range I intend to shoot at. This is quite normal on scopes I have used that have ballistic turrets such as swavorski ones ect.

Its all very well saying use an app but I have no interest in using apps when im out shooting.

I appreciate it is better to do this at the various ranges though I do not have this luxury right now.
All I was hoping for is to get say 200, 300, 400 and 600 meter marks roughly marked out on my turret so much so that I will be somewhere close to where I need to be.
 
Why not just use 1 scope that is suitable for both?
What is the point in swapping scopes?

Following up on my earlier comment. Where I am at just now is one rifle and two scopes. I have a rail on my Rem 260 and use a Swarovski for stalking and a March scope for range work. This approach worked well last year when I was using a NightForce borrowed from another Forum member for range work.

Regards

JCS
 
Scubadog - I banged some numbers using my Spire Point load at 3000fps into the JBM ballistics calculator and if figures that for a 300 meter zero I would be 5.1 inches high at 100 meters. The application will allow ranges in meters but I think it always gives the drop in inches.

I then gave it my Nosler Partition load at about 2700fps and it wanted to be 6.4 inches high at 100m for a 300m zero.

I hope that helps you a little, you can use the JBM ballistic calculator here:

http://www.jbmballistics.com/cgi-bin/jbmtraj_simp-5.1.cgi
 
Brill - thank you!


Scubadog - I banged some numbers using my Spire Point load at 3000fps into the JBM ballistics calculator and if figures that for a 300 meter zero I would be 5.1 inches high at 100 meters. The application will allow ranges in meters but I think it always gives the drop in inches.

I then gave it my Nosler Partition load at about 2700fps and it wanted to be 6.4 inches high at 100m for a 300m zero.

I hope that helps you a little, you can use the JBM ballistic calculator here:

http://www.jbmballistics.com/cgi-bin/jbmtraj_simp-5.1.cgi
 
All ballistic calculators give you a starting point but there's still no substitute for RWD (Real World Data).

Get down to the range and practice at different ranges/different positions/different weathers. Who knows, you may even enjoy it.
 
Show me the scope that is first class at both jobs and I will buy it. In nearly fifty years of looking through scopes, I've not seen one yet that is top drawer for both range work and stalking.

Have you tried Zeiss Ballistic Calculator
to help set up your scope?

Regards

JCS
Schmidt and Bender PMII 12-50x56 1st FP - Optics - Gun Shop, Shotguns, Rifles, Pistols, Air Rifles, Airguns, Gun Trader, Rifle Scopes, Accessories, Cabinets, Safes in Dorset and Devon, UK, Sportsman Gun Centre

Perfect >>>>>>>>>>
 
+1 With Long-range -rob Use ballistic charts etc to get you on paper. However use real world practice. I set my 270 up by poi 1.25" high at a 100m, this means anything out to 220m I dont need to think about hold over. At ranges over this hold over ponts on reticle comes into action. On my 6.5-284 and straight 284 then I set the tactical turret a 0 at 100m. When I stalk with these I carry them set at 1.25MOA so up to 220m is covered. Anything further out I use turrets to dial in. I used ballistic info to get on target but went out and shot at paper targets from 250m to 500m and recorded the MOA needed. I would say you need to shoot at paper to know what you and the rifle is doing at the distances anyways
 
Using an app will give exactly the same "theoretical" results that I am trying to do.
All I am doing is "calibrating" (for use of a term) my ballistic turrets to the curve of my theoretical trajectory. This is exactly what those of you do who use ballistic apps to get you on target.
Any way - thanks to those who have helped me do what I was trying to do.
I have now managed to set up 300, 400, 500 and 600 meter marks on my turrets.
I will be able to report back just how accurate this method is tomorrow - I am confident I will not be far out.
 
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