zeroing your scope

Discussion in 'Long Range Scopes and Other Optics' started by mike1113, Aug 15, 2009.

  1. mike1113

    mike1113 Active Member

    Messages:
    29
    Joined:
    Aug 5, 2009
    i want to start off by saying im new to tactical scope shooting,but i have kind of a stupid question. im wanting to zero in at 200 yards .when zeroing your scope do you return the turret to zero and nothing else.
     
  2. AJ Peacock

    AJ Peacock Well-Known Member

    Messages:
    2,229
    Joined:
    Oct 7, 2005

    Sight your rifle in, then loosen the set screw on your turrets and move them to zero. You want to only move the outside knobs, and not turn the mechanisms at all.

    HTH

    AJ
     

  3. 338 LEGEND

    338 LEGEND Well-Known Member

    Messages:
    196
    Joined:
    Jan 1, 2009

    What scope are you using? if it is one that the knobs pull up on removel you will just pull it up ,and set it to zero. this is after you are hitting at 200 yards. Hope this was your question.
     
  4. 338 LEGEND

    338 LEGEND Well-Known Member

    Messages:
    196
    Joined:
    Jan 1, 2009

    AJ
    You beat me to it!
     
  5. mike1113

    mike1113 Active Member

    Messages:
    29
    Joined:
    Aug 5, 2009
    ok thanks guys. by the way im using a super sniper 10x
     
  6. silvertip-co

    silvertip-co Well-Known Member

    Messages:
    1,131
    Joined:
    Jun 20, 2007
    I zeroed my rifle at 300 yrds for antelope and reset the knobs to the 'zero' settings. Don't forget to lock them on the
    '0'.

    My initial intention was to zero my Mod 70 7mm Rem Mag with mildot at 500 yrds, but practically speaking I intend to again hunt antelope with the rifle and I dont like the 14" I have to hold 'under' at 200 & 300 yrds if I should happen get a shot that close. With my rifle zeroed at 300 yrds I only hold 4" under at 200 & 100. Frankly I aint that good of a shot and dont anticipate a real 1k shot on brown fur. Altho I may go to my local 1600 yrd range and fire a few volleys at 1k just to see if I can prove the numbers( or get close to them ) on the ballistics chart thing I use.

    Handloads.Com Ballistic Calculator
     
  7. wrad

    wrad Member

    Messages:
    15
    Joined:
    Aug 8, 2009
    I'm about to graduate from sortoflongrange to verylongrange - out to about 1 mi. I am getting a new rifle w 34" barrel. Here is my dumb question for the year - it seems that a small error in zeroing at 100 yds can induce a large error at 1 mi. If I hold my rifle at the wrong spot on the 100 yd mark, I can actually be zeroing it for 97, or 103 yds instead of 100. I have not seen anything in tons of literature that tells me what part of the rifle should be on the 100 yd mark: the muzzle, front of scope, chamber, trigger, rear of scope, eye, butt of stock? I'm thinking the muzzle is the most logical choice, as that is where the bullet becomes ballistic until it reaches the target, exactly 100.000 yds away. That is my guess. Does anyone know for sure? Thanks.
     
  8. MontanaRifleman

    MontanaRifleman Well-Known Member

    Messages:
    6,068
    Joined:
    May 21, 2008
    Ward you make a good point. If you make a 1/2" error in your zero at 100 yds, that is the same as making 1/2 MOA error which would translate to 5" error at 1000yds. If you make a 1/2" error in your zero at 200 yds, that would be a 1/4 MOA error which translates to half the arc error at 100 yds. Another thing to consider is that some low drag bullets do not "go to sleep" by 100 yds which might throw off your zero estimation. My go to loads in my 300 RUM and 25-06 have an MV of 3400 fps and I zero them at 300 yds. That gives me a point blank range of close to 400 yds. At 400 yds they are dropping about 8 - 10" which is an easy (2 MOA) hold adjustment. At less than 3300 fps I would zero at 250 yds. To keep the high point of my trajectory at 3 1/2" or less. Zeroing as far as practical makes things a lot simpler in the field. Longer point blank range and less dialing or hold over farther out.

    A technique to fine tune your zero is to check it at a longer range. Lets' say you want a 200 yd zero (some bullets may not go to sleep yet at this range). Shoot a group at 200 for zero then shoot another group at let's say 500 yds to check your drop against your 200 yd zero. (This should be done after you have done some drop checks to confirm your velocity and BC.) If your data shows you should be 6 MOA and your actual drop is 6.5 MOA, then adjust your elevation zero by .5 MOA.

    For windage zero, I am considering zeroing at longer range to minimize the affect of coriolis and spin drift. If I zero my windage at let's say 800 yds, it may be off slightly at closer ranges (but not enough to matter) but should be very close at 1K plus.

    Just some things to think about.

    -Mark
     
  9. 4xforfun

    4xforfun Well-Known Member

    Messages:
    1,253
    Joined:
    Oct 1, 2007
    First off, your "97 or 103" yard thing equates to a gun 9 feet long. I have herd of long bbls , but 9 feet???:D

    Second, the difference between 97, 100 ,103 is + or - .01 inch in impact height. Exactly how good of a shot are you?????:D

    My point is.....we are all just a little to anal for our own good some times!!!!
     
  10. jwp475

    jwp475 Well-Known Member

    Messages:
    2,595
    Joined:
    Feb 4, 2005

    If you are of by.5 MOA with your ballistics soft ware, maybe your data imput is the problem. I've seen that before. I'd make that my velocity, barometric pressure, temp, humidity and all variables are correct, before I start rezeroing
     
  11. Ridge Runner

    Ridge Runner Well-Known Member

    Messages:
    987
    Joined:
    Dec 13, 2002
    Ok just crunched some numbers, using my 160 accubond load for my 7mm AM, sighted dead on at 300 yards its -496.09" at 1500 yards, but allowing for a 3% error if sighted in at 291 yards its -497.97" low at 1500 yards thats less than 1/4 MOA.
    RR
     
  12. MontanaRifleman

    MontanaRifleman Well-Known Member

    Messages:
    6,068
    Joined:
    May 21, 2008
    That's true. A .5 MOA adjustment would be significant and I just pulled that example out of the air. I agree, you want to make sure everything is correct which is why I said to confirm your BC and velocity with drops. That being said, I have never shot a set of groups (maybe 4 or more sets at various ranges) that exactly matched a ballistic curve of a particular BC and velocity. The point being then, I would fine tune my zero at a longer range for more precision at the longer ranges.
     
  13. wrad

    wrad Member

    Messages:
    15
    Joined:
    Aug 8, 2009
    Thanks all, for your great advice. And Mr. 4x... what's so wrong with being anal? I love crunching numbers, and often spend an hour on the 'puter with data, charts & statistics for each shot taken. VLR shooting and reloading just gives me a great excuse to play with numbers in very dramatic & fun ways. Now you can see why I asked my original question.

    No, my gun won't have a 9' barrel. Look at it this way. If I put the chamber of my rifle over the 100 yd marker (accurately measured to 0.1" with survey instruments), and the real range is supposed to be from muzzle to target, then my muzzle (on a 34" barrel + brake) is about 3' too far forward, and I am really zeroeing at only 97'. On the other hand, if I put my muzzle exactly on the 100 yd mark, and the real range is supposed to be from the chamber to the target, then my chamber is 3' back from where it should be, or at 103'. So I get a +/- 6' range within which I could be off by up to 3'.

    I did go into my ballistics programs to see if it made a difference, and like several other friendly responders pointed out, the difference seemed to be nil. Being a newcomer to this game I was not confident that I was doing it right, but I guess I was. But back being anal, where I reside most comfortably (I'm an engineer), even if it doesn't make significant difference exactly where you put your gun on the mark when zeroing - THERE MUST BE A RULE OR CONVENTION ON IT ! And I hate feeling stupid about anything, but not knowing were to put my gun when zeroing is just too stressful. If there isn't a rule, heck - let's make one.
     
  14. yobuck

    yobuck Well-Known Member

    Messages:
    853
    Joined:
    Aug 23, 2008
    the rule is playing games with computers is one thing and shooting at 1 mile is quite another. especially when your shooting at live animals. i would suggest you watch somebody doing some shooting at that distance at rocks. see how good you are at picking up bullet hits. then call back.
    a perfect 100 yd. zero is not that important. you will find you need a spotter with very good binnoculars if you expect success at any of the longer distances.