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Dredonn

Shooting correction chart

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Hey guys, I know there's a correction chart for pistols for why POI is where it is, I'm looking for one for rifles. Whenever I zero my scope and then move the target only 25 yrd, I'm hitting about 6" high, I'm doing everything the same way, but POI is way higher than its supposed to be. Any help would be greatly appreciated, because of this I'm not confident enough to go hunting in fear of a bad shot.

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I've always use the laser from the bore and adjust the reticle to the dot then fire for effect after removing the laser. 

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The pistol chart you refer to is based on the assumption  that POA and POI are correct and it points one to possible  factors a shooter may introduces. 

So how are you zeroing the scope? While it sounds like a basic question there are several ways.  

Also as edgecrushers is asking what distance are you initially sighting and then if moving out to 25yds the bullet is likely still on an upward trajectory. 

Useful information is rifle,caliber,scope, ring height,distance your 'dry' sighting 

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OP, you can't apply a pistol correction chart to rifle shooting, and the reason is - you're not shooting the rifle sandwiched in between both hands, at arms length (or close to arms length).  @edgecrusher hit it, though - what distance are you okay at, and then at what distance is it 6" off?... It also helps to know what position you're shooting from (sitting, kneeling, prone, standing), and if the shooting position is supported or unsupported (bipod, sandbags, sling, shooting rest, etc.).

If you're applying the fundamentals, that's one thing.  If you're not applying the fundamentals, then that's another.  Let's determine if this is a gun problem or a shooting problem... Here's what shooting mistakes look like, for rifle, and you don't follow the basics - Proper sight alignment, proper sight picture, proper breathing, using skeletal support and not muscle support, proper trigger squeeze, proper trigger follow through. 

It turns into just as many questions about you, and what you're doing, and the same for the gun.  What trigger, what kind of sights (open, red dot, magnified optics)...

Here's a chart that shows probable mistakes in rifle shooting:

RifleTargetProblems-667x394.jpg

Here's a bitchin' article on it:

https://www.returnofkings.com/87767/how-to-properly-fire-a-gun

Edited by 98Z5V

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Thanks for the replies, a little more info, I'm zeroing at 50yds, then moving the target to 75yds, I'm sitting at a very stable bench resting the hand gaurd only on a wood box they provide at the range. I just bought a bipod to attach to it so hopefully the next time I'll be able to use that instead of the box, also the rifle is .308 caliber and shoots very good groups even with cheap ammo.

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I know this pic is of the M16, but you get the idea.

If you zero at one distance and only move it out a short distance, the bullet itself is still on the upward angle of it's flight.

 

As in the military, the zero at a simulated target representing 300m at 25m away. Because the trajectory of the bullet is at the same height at 25m as it is at 300m. anything in between, you learn to aim lower to be able to hit center mass.

So you zeroing at 50 and moving to 75, yes your bullet is going to be on the high side.  

Trajectory-1-660x388.jpg

different-zero-points.jpg

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21 hours ago, Dredonn said:

Thanks for the replies, a little more info, I'm zeroing at 50yds, then moving the target to 75yds, I'm sitting at a very stable bench resting the hand gaurd only on a wood box they provide at the range. I just bought a bipod to attach to it so hopefully the next time I'll be able to use that instead of the box, also the rifle is .308 caliber and shoots very good groups even with cheap ammo.

@mrraley nailed it right on the money.

What are you going to use the gun for?  Is it a hunting rig?  How far out will you shoot, max distance?  Reason I ask, if it's tight woods and you only get a shot to 100 yards max, but sometimes as close as 25 yards...  then we need to figure out a zero for you based on Maximum Point Blank Range...  Need to know what your hunting - what animal - and what the engagement range is - like I said before, 25~100 yards, or 50~300 yards...   whatever the details are.

Reason on the animal - I set coyote guns up for a 5" vital zone, MPBR.  I set up a .308AR and a Gendel for 7" vital zone, for deer.

Edited by 98Z5V

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4 hours ago, 98Z5V said:

@mrraley nailed it right on the money.

What are you going to use the gun for?  Is it a hunting rig?  How far out will you shoot, max distance?  Reason I ask, if it's tight woods and you only get a shot to 100 yards max, but sometimes as close as 25 yards...  then we need to figure out a zero for you based on Maximum Point Blank Range...  Need to know what your hunting - what animal - and what the engagement range is - like I said before, 25~100 yards, or 50~300 yards...   whatever the details are.

Reason on the animal - I set coyote guns up for a 5" vital zone, MPBR.  I set up a .308AR and a Gendel for 7" vital zone, for deer.

The gun is used for hunting pigs, deer and coyotes,  in my area the woods are thick, so the range will be 5 yds to about 75yds realistically. I used the Hornady ballistic calculator and it show where with a 50 yd zero,  the POI should be about an 1 1/2" high at 75 yds, but I'm getting  about 5" high, I'm not sure if it's me doing something wrong, hopefully the bypod will help whenever I go to the range again. 

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On 10/1/2019 at 8:10 AM, mrraley said:

I know this pic is of the M16, but you get the idea.

If you zero at one distance and only move it out a short distance, the bullet itself is still on the upward angle of it's flight.

 

As in the military, the zero at a simulated target representing 300m at 25m away. Because the trajectory of the bullet is at the same height at 25m as it is at 300m. anything in between, you learn to aim lower to be able to hit center mass.

So you zeroing at 50 and moving to 75, yes your bullet is going to be on the high side.  

Trajectory-1-660x388.jpg

different-zero-points.jpg

Very good charting!

 

Of course you need to remember each caliber and loading has it's own individual  trajectory curve,  (as also the difference of the distance the scope is mounted above the bore of the rifle)  even different rifles of the same caliber have their own trajectory curve which may vary a bit from the standard ballistic chart. That is why you need to actually shoot each range and record the data or dope to establish the "dope" for sight adjustments.  Don't forget to also find and record the correct windage adjustments, for even a calm day, 

 

Edited by mrmackc

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19 hours ago, Dredonn said:

The gun is used for hunting pigs, deer and coyotes,  in my area the woods are thick, so the range will be 5 yds to about 75yds realistically. I used the Hornady ballistic calculator and it show where with a 50 yd zero,  the POI should be about an 1 1/2" high at 75 yds, but I'm getting  about 5" high, I'm not sure if it's me doing something wrong, hopefully the bypod will help whenever I go to the range again. 

This might or might not work for you, but here's an example of what's going on with the trajectory.  I made this chart up based on my .308 Win Hornady 150gr FMJ-BT handloads, and it only goes from 5 yards to 75 yards, in 5-yard increments.  The chart is based on a 5" vital zone.  Here's the drop you're going to see with a 20 yard zero.

789026251_Hornady150grFMJ-BT2600fps5to75yards1.thumb.png.f185b2ece9e40f9bb81ee6df3a2f9b18.png

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Run this program, play with the numbers, and see what you get.  You never know.  Plug YOUR load data into the columns/fields accurately.  Plug in your environmental for your area.  You might need a 12-yard zero, who knows.  This will help, just wade through the fields and input your data.

http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi

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2 hours ago, 98Z5V said:

This might or might not work for you, but here's an example of what's going on with the trajectory.  I made this chart up based on my .308 Win Hornady 150gr FMJ-BT handloads, and it only goes from 5 yards to 75 yards, in 5-yard increments.  The chart is based on a 5" vital zone.  Here's the drop you're going to see with a 20 yard zero.

789026251_Hornady150grFMJ-BT2600fps5to75yards1.thumb.png.f185b2ece9e40f9bb81ee6df3a2f9b18.png

I'm looking at your chart, if I'm reading it correctly,  you have a 20yrd zero and by 75yds it's dropped over 5 inches, with the ballistic calculator I use, it only drops about 2 inchs at that distance, maybe I input the info wrong. I'm still fairly new to this, but a 5 inch rise by moving the target 25 yrd just seems excessive to me, am I wrong or is that really plausible? I'm using factory ammo hornady american white 165grn with a 16 inch barrel, not sure about the actual velocity but I'm inputting 2500fps into the calculator.

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If you hit this thread right here, on Full30.com, it shows that same load from me, from 100~400 yards, from a 13.5" barreled .308AR.  From 100~300, it's pretty good.  I couldn't link the thread I made here, because the pics in the thread here are 404 for some reason.

https://forum.full30.com/t/zeroing-a-308-rifle-with-iron-sights/11194/25

If you want 5~75 yards, you really need to manipulate data, to get you what you want.  I can tell you this - it's gonna be something seriously weird, like a 14-yard zero or something - you need to play with numbers in ballistics engines, and find what works for what you're needing, and focus on Max Point Blank Range... 

What you need more than anything else, though - is the true muzzle velocity from the ammunition that you choose to use.  You need to run that hunting ammo over a chronograph, and find out what's making from your gun... :thumbup:

Edited by 98Z5V

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 Thank you for the replies gentlemen,  I'm hoping the bipod and level I bought will help take out whatever errors I'm making,  I'll find out next time I make it to the range.

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Just sight your gun in at 100 yards dead center of bull  then when you hunt you will be approx 2.5 inches low at 50 which on a animal the size you are hunting will not matter at all i hunt with a 308 168 grain bullet and sight in a 100 I have shot many deer at 50 yards and it make no difference with that sight in you will be good from zero to 200 + or - 3 inches go get them hogs!

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8 hours ago, Magwa said:

Just sight your gun in at 100 yards dead center of bull  then when you hunt you will be approx 2.5 inches low at 50 which on a animal the size you are hunting will not matter at all i hunt with a 308 168 grain bullet and sight in a 100 I have shot many deer at 50 yards and it make no difference with that sight in you will be good from zero to 200 + or - 3 inches go get them hogs!

EXACTLY   !      :thumbup:    Wash

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