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Scope sight-in question

Discussion in 'Long Gun Accessories and Optics' started by tcoz, Aug 10, 2017.

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  1. tcoz

    tcoz Member

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    Yesterday after boresighting a scope in my new RPR, I didn't have anything to do so I watched some videos on the sighting in process and saw a couple of people who advocated final range sight in be done by firing one round and moving the sighting point in the scope to the point of impact rather than adjusting to move the point of impact to the point of aim like I had always done previously. I had never thought about it before but this is almost a sure fire way to sight in with only two shots. I know that most of you can do it the traditional way with just a few shots but it always takes four to six for me to get it dialed in.

    I'm wondering whether POA to POI is a new way of thinking or has it always been used but just isn't as popular.
     
  2. Lafitte

    Lafitte Member

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    That will work ok but the rifle must not move at all while the adjustment is being done. Sometimes that can be somewhat of a chore, depending on the rest that you are shooting from.
    Lafitte
     
  3. tcoz

    tcoz Member

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    Hmmm, do you mean the rifle placement has to be exactly the same for both shots, which it seems is probably the case?
    If that's the case, it's a no-go for me. With a front bipod and rear monopod there isn't any way the rifle won't jump around.
     
  4. carsten1911

    carsten1911 Member

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    You just need to make sure that the rifle does not move while you adjust your recticle.
    Step 1: fire shot with a well defined, clearly visible POA
    Step 2: readjust your rifle so the scope´s recticle points at POA
    Step 3: Make sure the rifle does NOT move now: Adjust recticle to POI
    Step 4: fire shot at POA from step 1, POA should be POI now.

    Greetings
    Carsten
     
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  5. tcoz

    tcoz Member

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    Thank you carsten1911. I've got it now. As I get older (67), my brain acts more like closed-cell foam than the sponge that it used to be.
     
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  6. carsten1911

    carsten1911 Member

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    You´re welcome, Sir!
    In fact I just tested if I grabbed the 2-shot-sighting-in-thing myself, since I will help a rifle-newbie-buddy with exact this task one of the next days. ;)

    Have fun!
    Carsten
     
  7. cdb1

    cdb1 Member

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    I do it this way if I have a helper. If I'm by myself I do it the old way. It helps that I have a Caldwell Full Length Fire Control Rest. The joy stick makes it much easier to hold the rifle steady.
     
  8. jmr40

    jmr40 Member

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    That CAN work as long as you can keep the rifle locked into the same position while adjusting the scope. But I can get any rifle zeroed at 100 yards with 3 shots without having to resort to such tactics, or use a bore sight tool. Either way works just as well, it is really personal preference.

    The key is to get one bullet hole in a target at a known distance. It doesn't really matter how far the bullet impacts from the aiming point or the range as long as you know them. After that it is simple math to calculate how many clicks to move the scope. If you are using a quality scope shot #2 will be zeroed. OR, if you can keep the rifle locked into the same position it was when you fired it you can move the scopes crosshairs until they are on the bullet hole. I haven't found an easy way to keep the rifle in the same position. If you're using a lead sled or similar device it might work well enough.

    I shoot 1st at 50 yards. I either look through the bore and adjust the scope to get me close before firing, or use a large enough piece of paper that I can't miss, doesn't really matter. Once there is a bullet hole I can estimate distance from my aiming point and know that my scope will move point of impact 1/8" per click at 50 yards. If I wanted to be technical I could actually measure but many targets have 1" blocks which help with pretty close estimates without pulling out a ruler and walking downrange.

    Since I don't want my rifle zeroed at 50 yards anyway I'll adjust the scope to where it should be a 50 yard zero, but I always fire shot #2 at 100. It is rarely perfect, but within an inch or 2. I'll then readjust and fire a 3rd shot which is dead on 99% of the time. Then I start shooting 3-5 shot groups at 200 yards and will fine tune the scope adjustment as needed. Small errors often don't show up at 50 or 100 yards.
     
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  9. wally

    wally Member

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    The hard part is keeping the rifle from moving while making the adjustments. I find its the only practical way to sight in a laser sight and some brands of red dots. Its best at short ranges where the ammo's dispersion doesn't have such a large effect. For 100+ yard zeros, IMHO its best to get on the paper, shoot a three shot "group", and adjust POI of the group center to POA counting scope clicks and repeat as necessary -- this also heps verify your scope tracking is reasonable and its mounted plumb.
     
  10. Sunray

    Sunray Member

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    "...With a front bipod and rear monopod there isn't any way..." Yes there is. A bipod and rear mono isn't exactly stable. Nowhere near as stable or solid a rest as sand bags.
    "...POA to POI is..." Nothing new about it. There was an article in one of the gun rags 30 plus years ago about it.
    "...takes four to six..." Yes, you can sight in with 2 shots, but four to six is more fun.
     
  11. Legionnaire
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    Legionnaire Member

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    I use jmr40's method, but shoot a three-shot group before making adjustments. My sight-in targets have a one-inch grid on them, so it's easy to do the math. With a good scope, shots four and five are generally dead on. Way easier than trying to hold the rifle steady and aligning POA to POI.
     
  12. grampajack

    grampajack AR Junkie

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    Sounds reasonable to me. Just make sure the crosshairs are right on the bullseye and the rifle is locked down tight before you start turning the adjustments, and I don't see any reason that shouldn't work. I never shoot from a sled though, so it wouldn't be practical for me.
     
  13. TN Outlaw

    TN Outlaw Member

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    I hope no matter which method a person uses, that they shoot some groups afterwards to confirm zero and that the scope is holding zero.

    I like to dial to the POI and have used this method for years and its plenty "proven" for me. Ive done so with bags or lead sled without too much fuss. I havent counted clicks in 15yrs or so. Either way works just fine to get you on the bullseye with a load.

    Thing i dont understand about the bickering, other than it not mattering how someone else does it, is most folks i know, (including me) after getting sighted in, try a number of different loads and then fine tune to said load so it makes no nevermind how we originally got on the bull. Not to mention a handloader and all the shots and ladder tests they will go through afterwards. So as far as ethics of taking game goes, either sight in method makes no difference. The same person that would dial to point of impact and head to the woods after 2 shots would also shoot, count clicks and then go into the woods. Its the person, not the method. Neither gun would be truly woods ready until some fine tuning and group work was done.
     
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  14. John828

    John828 Member

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    To save ammo, I just try to remember what a particular gun's POI is and aim accordingly, e.g. if it shoots low and to the right, I aim high and to the left.
     
  15. grampajack

    grampajack AR Junkie

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    You've obviously read too many of Pat McManus's Field and Stream articles.:D

    +1. After you get a round in the general vicinity of the bullseye you want to shoot a 5 shot group, then make micro adjustments to move the group so that the bullseye is in its center, then ideally shoot a fresh group to verify it. 10 shot groups would be better, especially since they would show you heat induced POI shift, but good enough is good enough if all you're doing is shooting a deer inside 100 yds. Especially if you're shooting something expensive and painful.

    ............................................

    This would be the perfect method for sighting in a P90. I'm a longtime enthusiast of them, but their system of sight adjustment is a joke. It would also be the way to go if you had a lot of guns to sight in, like if you were a gunsmith or manufacturer or something.
     
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  16. Robert

    Robert Administrator Staff Member

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    Some of y'all need to spend more time at the range and less at the keyboard. I deleted a bunch of post. First and last warning, keep things High Road.
     
  17. tcoz

    tcoz Member

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    Lately I've been unpleasantly surprised at how a seemingly innocuous question like I asked can lead to some pretty nasty and insulting conversation back and forth. Once it begins, I usually just unsubscribe from the thread. It didn't used to be like that when I became a THR member a few years ago, in fact it's the reason I stopped posting on another well known forum.
    I guess it's just another sign of the times.
     
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  18. Flatbush Harry

    Flatbush Harry Member

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    I'm an old school guy and a long time NRA instructor. After I bore sight a rifle, I shoot 3 rounds at 50 yards to produce a group (done either from a bench using sand bags for support or prone with a bipod and rear bag). based on the group location (and at 50 yards, I get groups that typically are cloverleafs at worst), I compute adjustments of sights or scopes to center the groups at 50 yards. After adjustment, I shoot 100 yard 3-shot groups to find necessary corrections at the new distance, make them and voila, I'm sighted in at 100 yards. Takes me 9 shots at most. If I use a good rest, I use two-shot groups and get there in 6-8 shots. Once sighted in at 100 yards, I'll break out my Magneto Speed v3, get muzzle velocities, put the data into my AB program to get dope. Done.

    YMMV...this is how I do it.

    Harry

    NRA Certified Rifle Instructor
    NRA Endowment Life member
    Certified Crotchety Old Fart
     
  19. Robert

    Robert Administrator Staff Member

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    Please if you see this happening hit the report button so staff can take a look at it.
     
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  20. imashooter

    imashooter Member

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    If I do groups which are rare, I always choose a number other than the baseless arbitrary 3 or 5. It's a personal thing.
     
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