+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 10 of 14

Thread: 25 yard zero...

Click here to increase the font size Click here to reduce the font size
  1. #1
    Really Senior Member amadeus76's Avatar
    Join Date
    Dec 2016
    Last On
    Today @ 08:02 PM
    Location
    Harker Heights, tx
    Posts
    269
    Local Date
    11-20-2019
    Local Time
    09:06 PM

    25 yard zero...

    If Iím tying zero my Swissicon rifles according to the rear sight (300 for G11 and K11, 100 for K31) how many inches above my POA should my rounds impact?

  2. # ADS
    Friends and Sponsors
    Join Date
    October 2006
    Location
    Milsurps.Com
    Posts
    All Threads
    Banner AD Space Available - Click HERE to Inquire We specialise in military utensils and artefacts such as helmets, daggers, medals and badges, etc.  The on-line store is intended for personal browsing and searching of collecting objects. All items are provided historical value only and can be used for home collection or other purposes except of fascism, Nazism or other extremism manifestation or its propaganda. LIMITED TIME OFFER FROM THE AMERICAN GUNSMITHING INSTITUTE: Get Immediate Online Access To AGI's NEW Armorer's Course for Glock Pistols, Covering Every Generation of Glocks, Including the Latest Model 42/43 and Double Stack Pistols for ONLY $7.00! Brian Dick ... BDL Ltd. - Specializing in British and Commonwealth weapons Chuck in Denver ... Buy-Sell-Trade .. Guns, Cars Motorcycles Your source for the finest in High Power Competition Gear. Here at T-bones Shipwrighting we specialise in vintage service rifle: re-barrelling, bedding, repairs, modifications and accurizing. We also provide importation services for firearms, parts and weapons, for both private or commercial businesses. Banner AD Space Available - Click HERE to Inquire
     

  3. #2
    Advisory Panel Patrick Chadwick's Avatar
    Join Date
    Sep 2008
    Last On
    Today @ 05:24 PM
    Location
    Germany
    Posts
    4,743
    Local Date
    11-21-2019
    Local Time
    04:06 AM
    I apologize for this not being a straight answer to your question, but I do not think that trying to zero a rifle with open sights at 25 yards is a very good idea, UNLESS you use a target that is reduced in size AND know the trajectory of your ammo AND the height of the foresight blade above the barrel centre-line.

    If, for instance, you take the standard ISSF target with an 8" black and set it up at 100 yds, then a 6 o'clock POA is in fact a sight line that is below dead centre of the target by an angle given by InversTangent 1/900 (4"= 1/3ft viewed at 300ft). If you move the same target back to 25 yds, then the angle is InversTangent 1/225 (4"= 1/3ft viewed at 75ft) i.e 4 times as much. And at 25 yds you need to take into account that the barrel centre line is about 1" below the sight line, so the effect is even stronger. In effect, the barrel is aiming much lower than you think.

    If you want to fire a G11 at 100 you are going to need a higher foresight blade to get on target anyway. So to make it even roughly accurate, you need to know the exact height of the foresight above the barrel centre line AND the ballistics of your ammo. In addition, the sight picture of,say, an 8" black at 25 yds with a 6 o'clock hold, is different to that at 100 yds, and very different again to the sight picture at 300 meters (G11). This effect alone will cause a shift if you go straight from 25 to 300. So using a reduced target goes some way to ameliorating this effect.

    And forgive me for asking, but why do you want to zero at 25yds at all? I have been there and I have done that - and with a G11 to boot. And my experience was that at 25 yds/meters you can't do much more than make a horizontal correction and check that the shots are in the black. About 1.5" above the POA is my estimate - but you will not be able to set it up to be dead on at 100, much less 300, unless you really, really know the trajectory of the ammo you are using. Which means knowing the actual muzzle velocity as well.
    Last edited by Patrick Chadwick; 11-08-2019 at 12:07 PM.

  4. Avoid Ads - Become a Contributing Member - Click HERE
  5. #3
    Senior Member Pierre's Avatar
    Join Date
    Aug 2018
    Last On
    Today @ 09:19 AM
    Location
    Lost Prairie Montana
    Posts
    111
    Local Date
    11-20-2019
    Local Time
    11:06 PM
    Real Name
    Pierre St. Marie
    Yup. Patrick is right in there. The simple solution is to do it at 100 yards and we have the G11 front sight blade that will put you dead on at 100 yards. In fact we have all three, the G 11, the K 11 and the K 31. Just scroll down.

    SHOP | Swissproductsusa


  6. #4
    Really Senior Member amadeus76's Avatar
    Join Date
    Dec 2016
    Last On
    Today @ 08:02 PM
    Location
    Harker Heights, tx
    Posts
    269
    Local Date
    11-20-2019
    Local Time
    09:06 PM
    Thread Starter
    I recognize that 25 yards is not ideal, but itís a known distance and the idea is to zero at 25 yards and verify at 300 (for the G1911 and K11) and 100 (for the K31icon). But Iím not looking to zero them all at 100, I want the zero to roughly correspond to the rear sight graduations.

  7. #5
    Contributing Member Ovidio's Avatar
    Join Date
    Dec 2016
    Last On
    Today @ 07:20 PM
    Location
    Pordenone, Italy
    Posts
    738
    Local Date
    11-21-2019
    Local Time
    05:06 AM
    Real Name
    Ovidio Gentiloni
    I use the 25 meter or 50 meter zeroing in new rifles, where I have no real clue where they’ll hit.
    Once I’m on paper at that distance, and normally you always are, I know if I can stretch immediately to 100 and do the real job.
    It is just to prevent any discussions with RO ‘cause you’re shooting down the target stands or drilling someone else’s target...
    I consider it a step one, a very short step, but still a step to take with new toys.
    And works well.
    Last edited by Ovidio; 11-10-2019 at 12:58 PM. Reason: Typo
    34a cp., btg. Susa, 3į rgt. Alpini

  8. Thank You to Ovidio For This Useful Post:


  9. #6
    Contributing Member CINDERS's Avatar
    Join Date
    Nov 2009
    Last On
    Today @ 10:46 AM
    Location
    Southern Corner Western Australia
    Posts
    5,705
    Local Date
    11-21-2019
    Local Time
    11:06 AM
    Real Name
    CINDERS
    Yeah Ovi if your dealing with an unknown or swapped a blade out 25 is a good start they have the 25 yard target on this site for the 303's but with hand loading it all but makes it superflous the only real measure is to do the hard yards and get the dope of the ranges you shoot by actually shooting them and even then its is a little hit and miss due to atmospherics time of day height above sea level etc etc.
    But to give you a clue I concur with you Ovidio 25 yards to get you at least knowing where the rifles going I have seen so many guys try to zero without knowing where the rifles printing just give up because they are not even on the target!!!

  10. #7
    Contributing Member Ovidio's Avatar
    Join Date
    Dec 2016
    Last On
    Today @ 07:20 PM
    Location
    Pordenone, Italy
    Posts
    738
    Local Date
    11-21-2019
    Local Time
    05:06 AM
    Real Name
    Ovidio Gentiloni
    That’s it. New and wholly unknown rifle. If I hit in the black at 25, then I’m safe to go at least 100.
    Usually I hit paper also at 100 with new rifles, but I have seen a good pal of mine getting crazy, until we went to the pistol range and found out his Mosin was off by 4” at 25 meters. At 100 he didn’t even come close to his target.
    Maybe the neighbour’s
    34a cp., btg. Susa, 3į rgt. Alpini

  11. Thank You to Ovidio For This Useful Post:


  12. #8
    Contributing Member CINDERS's Avatar
    Join Date
    Nov 2009
    Last On
    Today @ 10:46 AM
    Location
    Southern Corner Western Australia
    Posts
    5,705
    Local Date
    11-21-2019
    Local Time
    11:06 AM
    Real Name
    CINDERS
    My point exactly I have seen a guy years ago nearly wrap their 303 around the tail gate of their ute as after 10 rounds at a hundred meters zero hits! I remember shooting full bore I had a Sportco 308 coached at 900M 12 misses for a zero score I was well please when I got up from the mound so I know what it feels like to wash out with a rifle that you do not know where it is printing

  13. Thank You to CINDERS For This Useful Post:


  14. #9
    Contributing Member Aragorn243's Avatar
    Join Date
    Apr 2009
    Last On
    Yesterday @ 11:46 PM
    Location
    Pennsylvania, United States
    Posts
    4,928
    Local Date
    11-20-2019
    Local Time
    10:06 PM
    Add Aragorn243 on Facebook
    Real Name
    Steve
    Might be completely different but I always zero my scoped rifles at 25 yards. Been doing it for 40+ years. Bullet is still rising at 25 yards so it will hit a bit high between 25 and 150 yards, be dead on at 150 and start dropping after that. For deer hunting it's a dead deer from 25 to 200 yards without altering the sight position After that you have to start aiming high. Fairly flat trajectory 243 although I've done the same with 300 Savage. Don't exactly need precision for deer, you have a 5 inch circle to hit, probably more. Then again, I rarely shoot a deer further than 75 yards away.

  15. Thank You to Aragorn243 For This Useful Post:


  16. #10
    Senior Member Pierre's Avatar
    Join Date
    Aug 2018
    Last On
    Today @ 09:19 AM
    Location
    Lost Prairie Montana
    Posts
    111
    Local Date
    11-20-2019
    Local Time
    11:06 PM
    Real Name
    Pierre St. Marie
    I do understand what you're intending to say, but for those who don't quite understand, no projectile can rise. At the point it leaves the muzzle it is dropping, indiscernible at first but unless it's rocket powered, it cannot rise.

+ Reply to Thread
Page 1 of 2 1 2 LastLast

Similar Threads

  1. Yard Sale Find - No4 MK2
    By Aragorn243 in forum The Lee Enfield Knowledge Library Collectors Forum
    Replies: 16
    Last Post: 09-05-2013, 12:29 PM
  2. My fav 100 yard .22
    By MJ1 in forum .22 Smallbore
    Replies: 5
    Last Post: 04-11-2012, 10:31 PM
  3. The 'Bone yard'
    By Harlan (Deceased) in forum The Watering Hole OT (Off Topic) Forum
    Replies: 15
    Last Post: 07-02-2011, 07:32 PM
  4. 100 yard sight zero possible?
    By three0three in forum Pattern 1913/1914 and M1917 Rifles
    Replies: 14
    Last Post: 11-29-2009, 12:24 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts