Grouping satisfactory?

Discussion in 'The Basics, Starting Out' started by skip AI, Feb 12, 2006.

  1. skip AI

    skip AI Well-Known Member

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    Are 50mm groups at 250m any good? Using .25-06 AI with 10X scope.
    The crosshair thickness of my scope has made it hard to group tight at long distances.

    cheers
     
  2. remingtonman_25_06

    remingtonman_25_06 Well-Known Member

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    What is that in inches?? I dont know mm's. It all depends on what your hunting for. For pdogs, obviously you want the most accurate possible. For deer you still need good accuracy but not as good as for an elk. You see what I mean. For LR shooting, I believe most people want 1/2 MOA. So for 250 yards, a 1.25" is good, but I would say 1.5"-2" is plenty for deer size or yotes, but for pdogs you need better then that to get consistent hits at longer ranges.
     

  3. skip AI

    skip AI Well-Known Member

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    It is 1.968"

    cheers
     
  4. skip AI

    skip AI Well-Known Member

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    BTW I hunt foxes mostly.
     
  5. Varmint Hunter

    Varmint Hunter Well-Known Member

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    Your groups should be quite adequate for shooting fox out to 500yds or so. In theory, you would still be shooting under 4" groups at that distance. Well within the vitals of a fox.

    However, fox are not normally shot that far, thus, making your set-up just fine.
     
  6. Bart B

    Bart B Well-Known Member

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    [ QUOTE ]
    Your groups should be quite adequate for shooting fox out to 500yds or so. In theory, you would still be shooting under 4" groups at that distance.

    [/ QUOTE ]

    In reality, groups open up as range increases; they are never linear in the angle they subtend. Depending on the variables in ballistic coefficient and muzzle velocity spread, a 50mm group at 250m can easily be a 150mm or larger group at 500m.
     
  7. Varmint Hunter

    Varmint Hunter Well-Known Member

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    [ QUOTE ]
    In reality, groups open up as range increases; they are never linear in the angle they subtend. Depending on the variables in ballistic coefficient and muzzle velocity spread, a 50mm group at 250m can easily be a 150mm or larger group at 500m.

    [/ QUOTE ]

    That's why I said "In theory". Occasionally, a rifle may even shoot groups that shrink with distance, when measured in moa.

    Either way, his rifle should be fine for the intended target.
     
  8. skip AI

    skip AI Well-Known Member

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    I want and expect 4" groups at 500m, I shoot 12mm (0.472") groups at 100m.
    There was a 15mph wind aswell.
    What can I do to improve accuracy?

    cheers
     
  9. Bart B

    Bart B Well-Known Member

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    [ QUOTE ]
    Occasionally, a rifle may even shoot groups that shrink with distance, when measured in moa.

    [/ QUOTE ]

    I've never heard of one that'll do it consistantly. If there is such a bunch of bullets loaded that do, then they all have special properties that change their direction back towards the down-range group center. And they all know not only where they are amongst the trajectory paths of previously fired ones but which way to change their trajectory; down, up, left, right and combinations of each one. Such bullets are truly magic. The faster ones must slow down a bit so they don't strike too high down range; the reverse must happen with the slower ones so they don't strike low. Most interesting is how the ones on one side of the trajectory paths horizontally.

    And if it's the rifle that's causing this to happen, how in the dickens does it make the bullet change directions?
     
  10. sambo3006

    sambo3006 Well-Known Member

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    Bart B, I opened this particular can of worms a month or two back and ruffled some feathers unintentionally. While I don't buy the fact that a rifle will shoot smaller groups (aboslute measurement, not moa) at longer distances, the moa thing might be plausible comparing 100 to 200 yd groups(maybe farther, I don't know). The explanation I got was that long for caliber bullets may not be sufficiently stabilized at short distance due to the fact that they spin around center of form in the barrel and then try to spin around the center of mass after they leave the barrel, thus causing the bullet to oscillate around the tip until it begins to spin around the center of mass. This is a very simplified explanation, but hopefully it makes sense. Anyone else more knowledgeable on this subject, feel free to illuminate us common folk /ubbthreads/images/graemlins/grin.gif
     
  11. Buffalobob

    Buffalobob Writers Guild

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    If your crosshair is giving you grief, try using a corner of it and make a target designed to look like a right angle so it will fit into the corner of the cross hair. This may make your groups "measure" smaller on paper but you will still encounter the problem in the field with the thick cross hair.
     
  12. remingtonman_25_06

    remingtonman_25_06 Well-Known Member

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    I was testing loads for my dads Ruger mk2, S/S yesterday. Rifle is totally stock except for a timney trigger. No bedding, not floated. I was testing the 75g vmax and IMR-4350 for him for coyotes. Scope used is the VX2, 6-18 Target. I was getting 3725fps and .75" 3 shot groups at 100 yards. I wanted to shoot a group on paper at 500 yards to make sure the clicks would be "dead on". Good thing I did this because it took 2 clicks more to actually be dead on. I knew this firsthand because before I shot the target, I set out a milk jug and I hit the bottom of it. I went up 2 clicks and busted that thing open. Then I shot my 3 shot group at 500 yards. The bullets were landing perfctly for up and down, but with a 5mph wind to the left, they were about 6" to the left. Not much to my surprise, my 3 shots measured an even 4". Not bad for a Ruger with nothing more then a trigger job. He was totally happy with it, and you know what, I would be to. He will be busting yotes at 500 before he knows it. /ubbthreads/images/graemlins/smile.gif I like to draw 1 inch squares at 100, 2 inch squares at 200, 5 inch squares at 500, you get the idea. It makes aiming a ton easier. I hate circles now that I got the square idea from somebody on here. Makes it a ton easier to bracket the duplex and get an exact aiming point shot after shot. Anyways, heres a pic of the 4" 3 shots at 500 yards with the 75g vmax and the stock ruger S/S in 25-06.

    [​IMG]
     
  13. skip AI

    skip AI Well-Known Member

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    On my rifle it has a 56mm Objective, I was doing some dry fire practice today and found I was lifting my head off the stock to look through the scope.
    Does anyone think that a posative cheek weld to the stock is needed for accuracy?
    I got out my .300 WSM with a 33mm objective and I found that I could hold it as steady as my varmint rifle without a bi-pod!
    I think I might need to get one of those stick on cheeck pads, anyone know who makes them?

    remingtonman_25_06, I want mine to atleast do that /ubbthreads/images/graemlins/mad.gif /ubbthreads/images/graemlins/wink.gif

    cheers
     
  14. Bart B

    Bart B Well-Known Member

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    [ QUOTE ]
    Does anyone think that a posative cheek weld to the stock is needed for accuracy?

    [/ QUOTE ]

    It makes a big difference. The longer the bullet takes to get out of the barrel the greater difference it makes. It's most critical on .22 rimfire rifles but less so with center fire rifles. Variables in cheek pressure cause vertical shot stringing.

    Yes; get a cheek piece pad or something to keep your shooting eye perfectly centered in the scope's optical axis. Note that the cheek piece height needed may vary with the position you're using. Which means one adjustable for height is best.