How accurate must the zero range be?
 

How accurate must the 100 yard zero be to make hits out to 1000 yards? Is it plus or minus 1 yard, 1 foot, 6 inches? Where to I measure from? I have read from the end of the barrel and other have said from the turrets of the scope.

No one can help, question lacks enough detail to provide any answer that makes sense. What scope, is it a Ballistic turret, mil dot reticle, other form of hold over reticle, 1st or 2nd focal plane, power range, cartridge you are shooting, bullet weight, velocity and B.C. of the bullet. We try hard around here to help guys out but you do have to do your part too.

The 100 yard zero has to be dead on.

If it's not, the longer the shot, the bigger the difference between POA (point of aim) and POI (point of impact).

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I foot or so wont matter much.. I have shot sub moa sized groups on targets from different positions shot to shot.. I have a target set up at 100yds ( roughly) and day after day i can just walk out to roughly the same spot and put a supported first round hit in the same spot day after day ( sub moa group shot over the course of a few days) there is no way i am shooting from exavtly the same spot every time..

what caliber , what scope are you running...[target turrets ...elevation ] , do you have a rail..20moa + ? ... 1000 yds is very do able by lots of guys on this forum but not a chip shot.

If I am zeroing a rifle at a 100 yards and know the rifle will be shot at 1000+ yards I make sure I have exactly 100yards from the muzzle to the target. I also do a tracking test on the scope.

You realise this makes no sense, right? If you are dead on at 100, aim for the 1000 yard target, you won't even be close. You either need to adjust the turret or have some kind of hold over system, and even then, cartridge, B.C.. velocity and wind all come into it. You can be dead on a 100 and if you get your dial up or wind hold wrong you are still going to hit sweet FA.

There is a ton of variables that are far more important than the +/- less than a yard that you are referring to
Your rangefinder has a larger tolerance at 1000 yards than what your trying to compare

I have yet to find a rangefinder that will give you an exact everytime measurement down to the inch....its even harder still to transfer that exact measurement to the very tip of your barrel...or scope turret for that matter.. real world experience tells me for typical hunting / precision rifle there are way more important things to be concering yourself with when looking at hits at 1000 yds than if your rifle was zeroed at exactly 100yds from a certain exact point on your rifle system.

Marky said it better than I..

Nah he makes sense
He’s saying that if your poi and poa aren’t the same at 100 yards your going to be in trouble if your shooting out to 1000
I 100% agree

The ballistics and optics questions are totally different subject

First ask your self how accurate is your range finder? Some can be out .5% after 450 yards. That equates to +/- 5 yards at 1000 yards. And that is not cheap models either. Look at the specs on the leica geovid 3200. I was surprised myself by the number.

So is your measurement from the barrel end, or your glass end gonna make a difference? Make it consistent is all. I read my ranges from behind the rifle every time, so they are from the same spot regardless of range.

What will make a difference is your ability to read wind, and having some trigger time working up to the 1000 yard marker.

Wind does not materially affect POA and POI at 100 yards, unless you are in a gale. Whether those two are on at 100 or not, is irrelevant to hitting something even at 500, let alone 1000 yards. All you need is a 5 mph breeze to show that to be true. Ballistics are VERY germane to the issue, as is the method used to adjust the hold.

Can't see where he was not making sense. Please.. explain .

+/- 3 to 5 yards at 100. Beyond a couple hundred yards literally EVERYTHING ELSE will have a much greater effect on your ability to make impacts at distance.

To ease my mind I simply use my range finder and zero my rifle at the distance the rangefinder says, so then my ballistics app knows I zeroed at - for example- 97 yards. At least this way I’m consistent. I use the same rangefinder for distant targets and then at least I’m dealing with the same set of inconsistencies.

Theoretically, if the ammo/BC and all other data are perfectly known and verified, you could zero at any distance whatsoever and the ballistics calculator could extrapolate from that. You still need to verify your theoretical DOPE at various ranges under various conditions anyways. 100 yards or 100 meters is just easy to do and typical reduces environmental factors when zeroing.

To put things in perspective
, if you are one inch put at 100 yards ( approx. 1MOA) you will be 10 inches out at 1,000 yards .

But I am not sure if you are talking about your scope accuracy or your range finder accuracy, or your own marksmanship ability .
There are a great number of variables( as was mentioned ) in consistently making a first round hit at 1,000- even a 1MOA hit ,after dialing up from 100.
Cat

I would suggest you purchase a book and or do some research...

May I suggest one called....

The ultimate optics guide to rifle shooting

by CPL. Reginald J G Wales ( CAF Ret. )

cost about 35.00 got mine at Cabelas lots of info

Just to ask a question and get a definitive answer isn't happen

you need range time

Good Luck

I could be wrong, but looking at the OP's join date, and post count, I think he just trolled a whole bunch of very smart guys.

I could be wrong. He may be legit.

But he also hasn't replied to anyone on the thread he started. Things that make a mod go hmmmm.

It needs to be accurate, but you will get more variables from your program than a barrel length matters. Best bet is zero at 100 then test at 300 and 600 yds. This will tell you how accurate your program is.

this

If he’s trolling, I know one guy he didn’t get. Dean2

Big "IF"

If you are offended, take it up with the mod a few posts earlier.

It may also be that he got his answer and just didn't think to respond.
As far as a troll post goes , if it was it eas a pretty lame one!:sHa_sarcasticlol:
Cat

I suspect the original post is asking about consistency at close range and the effects at longer distances. Let's give the benefit of doubt before another thread turns into hurt feelings.

I sight all my rifles in at 100 metres and use that zero for additional range adjustments. After shooting a tight confirmation group at that 100 metres, if I were to move closer or further back, let's say 10 metres plus or minus, the bullets are punching through the same holes from the previous 100 metre grouping. Lots of variables at play; weather, consistency of the powder, projectile (mass and shape), and most importantly is my position and hold behind the rifle. I do not see much change in POI with moving that 10 metres plus or minus of the 100 metre distance with my main hunting and target rifles. Now, providing I am doing my part in punching a very tight group at 100 metres, I can then reach out further, providing that I correctly read and respond to the conditions of range, ballistic path and drop, temperature, wind, etc. Again, lots of variables at play, but I must first shoot a tight group up close, then practice at various ranges if I have any chance of making the long distance shots.

exactly.

Not offended at all .. Are you the new Robo cop ? how goes the post count ?

If i read it correctly he was asking exactly how 100yds should be measured and to what part of the rifle from target. Ie should it be exactly 300ft (100yds) from his muzzle? 300ft from his occular lense? 300ft from his turret? What if its 301 ft ? Will it affect dope out to 1k? What if his 100yd zero is actually 303ft from his turret but only 301.97 ft from his barrel.....will it matter??? I would imagine there are far more pertinent issues with bot sighting in and zeroing and definitely at 1k than what he was asking about...if its even a legit question

Ballistic Calculators & Field Results
 

I was asking about Ballistic Calculators & Field Results. I'm not here to troll anyone. Thank you all for your response.

Was i correct in how I read your question about how accurate you have to be at 100yds?