ZERO'ing

[Orka Akinse]

Dudes & Dudettes

 

I know this is not strictly speaking "marksmanship principles" but it does goe a long way in getting the principles sorted as a PROPERLY zero'd rifle will aid the principles.

 

 

So who is going to write the definitive way to properly zero?

[Scotch_egg]

The way I zero is to bore sight on to target. Then fire the first shot aiming at my reference usually an inch square on my target board.

 

2) After this make sure the rifle is not loaded. Postition the rifle on bi-pod/bags or similar so it is supported in the aiming position with the cross hair on the same point of aim reference.

 

3)Then move the cross hair to the point of bullet impact ensuring the rifle does not move

 

4)Take second shot. Check point of impact. This should be spot on.

 

This method works for me.

[Chris-NZ]

That's the Scotsman's approach- save ammo at any cost..

 

Works in principle but your rifle must be dead accurate (ie capable of tiny groups routinely) -and- you need to be sure both shots are perfect. Neither is certain in the real world for most people.

 

A more traditional approach is to set up a target with an inch square grid on it at an exactly-known distance and fire a three shot group, possibly after a fouling shot if your rifle needs it. Calculate the number of clicks necessary to move the centre of the group to the desired zero point, apply the corrections, fire another group and see where you now are. In most cases, some slight additional correction is necessary but the key thing with this approach is you can be more certain where the zero is.

 

Chris-NZ

[terryh]

Orka,

 

I'm a bit in between the 2.

 

I either bore sight or fire a couple of shots 'close' say 50 yards and carry out any 'big' adjustment by estimating the corrections. This will get you on the paper and foul up the barrel, removing cleaning errors etc.

 

Then fire a group aiming at a fixed 'dot' of a known size (or gridded paper as per Chris) at your zero distance. Work out the corrections, apply and fire another group to proove.

 

Do not think you can put a definitive method on this sort of thing really? You might have to carry out some additional checks after preliminary zeroing dependant on your reliance on first round CCB and CB shots.

 

Terry

[Snowz]

before any of that tho you should mechanically zero your scope..... you could zero the scope without doing so and soon run out of elevation or windage

 

wind your turrets all the way to one side, then slowly and carefully count how many clicks it takes to wind all the way to the other side, do this for both windage and elevation.

 

Then half the amount of clicks for each e.g 140 clicks is 70 clicks half way.

 

Now turn the turrets to these half way position, and now your scope is mechanically zeroed.

 

Now go and try any of the above the above.

 

i personally shoot at a small dot, its easier to make sure that the crosshair is on the same spot everytime compared to a large dot where the crosshair will float around in it.

 

bore sight @50yds take a couple shots to check windage and elevation,

 

i then bring the windage in to the zero spot and then the elevation somewhere near,

 

i then move out to 100yds and fire a few shots and make any further adjustments to windage and elevation.

 

once zeroed i take a further few shots to confirm,

 

i take my time and dont string my shots i fire 3 shots slowly and let the barrel cool down before starting the next 3 shots, this will prevent stringing and getting a false zero

 

 

hth Richard

[Chris-NZ]

What you describe Richard (prior to the shooting bit) is more of a preliminary check of the quality of components and assembly. It's really a check of whether your base(s) are askew.

 

If they are, you could end up miles from the mechanical centre of the scope to achieve a zeroed rifle.

 

Chris-NZ

[Snowz]

What you describe Richard (prior to the shooting bit) is more of a preliminary check of the quality of components and assembly. It's really a check of whether your base(s) are askew.

 

If they are, you could end up miles from the mechanical centre of the scope to achieve a zeroed rifle.

 

Chris-NZ

 

 

if you do it properly the first time as in check your mechanical zero it saves a waste of any time and ammo if you do run out of adjustment etc, there's only one way to do something and thats the right way

 

my opinion and that of many other shooters i know, i could also list a few other things to do before fitting bases, rings and scopes to a rifle but it's prob a bit anal and might not make a huge difference but when you shoot long range it all makes a difference

 

atb Richard

[CliveWard]

That's the Scotsman's approach- save ammo at any cost.. :P

 

Works in principle but your rifle must be dead accurate (ie capable of tiny groups routinely) -and- you need to be sure both shots are perfect. Neither is certain in the real world for most people.

 

A more traditional approach is to set up a target with an inch square grid on it at an exactly-known distance and fire a three shot group, possibly after a fouling shot if your rifle needs it. Calculate the number of clicks necessary to move the centre of the group to the desired zero point, apply the corrections, fire another group and see where you now are. In most cases, some slight additional correction is necessary but the key thing with this approach is you can be more certain where the zero is.

 

Chris-NZ

 

Chris,

 

This is how I do mine, after boresighting first

 

Then theres the old chestnut of getting your reticle level (if you hold over) or your erector level (if you dial in).

 

 

Cheers

 

 

 

 

 

Clive

[Chris-NZ]

Yeh Richard, you're quite right on the need to check mechanicals for long range applications but OA didn't mention that requirement.

 

Maybe someone should write a stickie on scope mounting that would of course include that. That's why I didn't cover bore-sighting Clive as I'd assumed it'd be done beforehand.

 

Chris-NZ

[Snowz]

i can post a copy of something that is on another site if allowed by mods on here and on the other site, OR i'll pm Varmartin as its his posts i would be copying and ask him to post them on here, they are very informative threads.

[lancslad]

I tend to zero by boresighting first as explained previously.

 

next.

 

I will take 3 shots (quick sucession) with barrel just being cool to the touch about a min and half between shots. then look at the mean point of impact. adjust accordinlgy in 1 plane, horizontal or vertical.

 

Next take another 3 shots and adjust again.

 

Normaly Im on after 10 shots, but that dont bother me as Im reloading.

 

 

However, Im going to start "clean" barrel zeroing shortly........................Im hunting, not target shooting, so once Im 3 shots in 1inch Im happy with that..............

[Tank]

All sounds good. I've heard about mechanically zeroing the scope but not done it yet. I boresight my rifle and it does save ammo and consequently money. I suppose if you have windage adjustable mounts that mey help if you don't mechanically zero as you shouldn't in theory run out of adjustments?

[devilishdave]

Take your time fire 5 shots ensuring each shot is executed well whilst employing the marksmanship principals. Find the centre of your group and mark it. If you know what the value of each click is then the adjustments are simple maths, i.e. if you are an inch low and an inch right and it is ¼ moa per click then 4 clicks up and 4 clicks left and you should be sorted.

 

Fire confirmatory group then congratulate your self on understanding one of the most basic principles of zeroing your rifle.

 

Dave

[Mash67]

if you are going to mechanically center your scope then would you not need mounts with adjustment to keep the scope as centered as you can,unless your lucky enough to have a combination that put you very close to center in the first place otherwise your just going to adjust the crosshairs to where the bullet strikes anyway

matt

[lowspeed]

I'm new here, thought I may as well jump in here as well as anywhere else...

 

I always obtain a mechanical zero with my irons or optic then determine the "near zero" for the particular round I'm shooting. For instance my 223 AR the near zero for a 62 gn. FMJ commercial load is 41 meters. The "far zero" is 250 meters if I recall correctly. I will zero at 41 meters using five shot groups.

 

Once I'm zeroed at 41 meters I will confirm it at the far zero of 250 meters, if I've done my part I should be shooting a 2 MOA group (my limitation) at 250 meters. I then know that I should be plus or minus about 3 inches elevation from the muzzle to 250 meters. The purpose of my AR is to keep me alive from 0 to 250 meters so I don't worry about what occurs in between as long as I'm within those tolerances.

 

When I zero my Model 70 which is a 243 Win. the near and far zero are different but the same principle applies. SInce I want more precise feedback I will post targets at 50 meter intervals from the far to near zero and shoot groups on each one recording the results. I can usually depend on this information throughout environmental changes and adjust for wind only.

 

While this method readily provides a basic zero to fine tune from it requires knowing the trajectory of a given round beforehand, with some rounds this is easily obtained, for others it's a needle and haystack exercise.

 

I will apologize in advance if this is too basic for precision shooting but I've found it to be the fastest way to get rounds on target for a "jumping off" point.

[tony]

Lowspeed, If this works for you then great, everybody has there own prefered way of doing things

Tony.