Can Anyone tell me why

[hatfield954]

Okay, here is my story. I was sighting in my new rifle. A savage model 12 with 26 inch barrel, 308 caliber, 168 grain ammunition, 3-9x40 leupold scope. I started at 25 yards. Being dead center of target after 6 shots at 25 yards, I then moved target out to 100 yards. The very first shot at 100 yards, I didn't even hit the target. I found out after many shots, that the rifle was very high at 100 yards. Can anyone tell me why it jumped like that, from 25 to 100 yards? I have used the same sight in method for my other rifle and didn't recieve that trouble.

 

[KRP]

Really tall base and rings?

 

[hatfield954]

No sir, I have a one piece medium height scope mount. The scope is close to the barrel like it should be.

 

[Browninglover1]

I've found that if I get on paper at 25 yards that I should put the groups between 1-1.5" low at that distance to have them hit close to center at 100 yards. I did the same thing you did but I was shooting a 7mm mag that was dead on at 25 yards and missed the target at 100 yards. I have since learned that in my experience if you keep the POI about 1 inch low at 25 you'll be a lot closer at 100.

 

[str8shoot]

When you look through your scope you are looking straight at your target. Your barrel however is angled slightly upward, creating an arched trajectory. The trajectory crosses the line of site twice. The top of this trajectory is usually at 175- 200 yards. If you sight in for 25 yards your bullet is still rising and will always be high at 100, and then will be on again at around 300 yards.
Realize however that if you sight in at 100 yards you will probably only be an inch or so low at 25 yards. If you shoot at 25 yards and are an inch low you would have to come up 4 moa in order to be on. 4 moa at 25 yards is 1 inch, 4 moa at 100 yards of course is 4 inches. So you can see how easy it is to be pretty high at 100. Scope height plays a factor in this also, the higher the scope is mounted the more you will be off at 100 yards after sighting in at 25.
I hope this make sense.

 

[436]

You didn't say what the dimension of your target was your were shooting at, example; 8x11 Did you by chance staple it at the very top of the back stop frame along the upper ledge? When you say you found out later the shot was "very high" can you say "how high" it was?
436

 

[ken snyder]

Just simple math. do this, on a piece of notebook paper draw a real long rectangle. then draw 2 lines each from corner to corner in a big X fashion. The lines intersect in the middle ( 50 yds.) Now do the same but make the lines inersect at 25 yd. ( 1/4 the way across your rectangle) those two lines represent your line of sight and your bullet trajectory. Make a scale version add in your sights heighth ( center of bore to center of scope ) and it will become obvious as to why you are hitting so high-- zero for 50yds and 100 yds are almost identical not 25yds.

 

[hatfield954]

The targets I am using for that distance are 12 inch round on a 14x14 inch square back board. It was more than a foot high, when I moved out to 100 yards. The bullets were popping a tree behind the target where I had my target stand. I also found out that the elevation knob on the scope is *** backwards from my thinking. To make the crosshair move up, you turn the turret in the down direction. To make it move down, you turn it the up direction. So while I was trying to make scope corrections, I was actually making them worse.

 

[ken snyder]

I do the same thing once in a while, one time I was trying to zero a scope for a friend and it took me 3 shots to realize he had mounted it 90º counter clockwise ( another swoosh right over the top of my head moment )

 

[KRP]

I also found out that the elevation knob on the scope is *** backwards from my thinking. To make the crosshair move up, you turn the turret in the down direction. To make it move down, you turn it the up direction. So while I was trying to make scope corrections, I was actually making them worse.

They are labeled correctly for moving POI.

 

[436]

hatfield954
This might help you visually to understand what's happening if you zero the rifle dead on at 25 yards; you can see your at about a 210 yards'…, you have to bring the clicks "down" Your rifle is locking on to a 210 yard field zero with a dead on 25 yard range zero. Yep playing with the elevation did sound like it was helping you… most scopes turn right and up for elevation, I'm sure that was a problem within itself.

You may trying going back out to the range at 25 yards… not meters, having the poi {point of impact} 0.50" mao or ½ inch low of your point of aim; as someone has all ready mentioned. This should put you dead on at 100 yards {mathematically}

If for some reason this doesn't work for you… go see a gunsmith, there's something else going on with the rifle or the scope.
Good luck
436


Range (yd) Clicks ¼ moa zero 25 yards
--------- ------
0 0
25 0
50 -9
75 -10
100 -10
125 -8
150 -6
175 -4
200 -1
225 1
250 4
275 7
300 10
325 13
350 16
375 20
400 23
425 27
450 30
475 34
500 38
525 42
550 47
575 51
600 55
625 60
650 65
675 70
700 75
725 80
750 86
775 91
800 97
825 103
850 109
875 116
900 122
925 129
950 136
975 143
1000 151

Click chart generated for .308 168-GR HPBT MK
Muzzle Velocity = 2650 ft/sec, BC = 0.462

.308 168-GR HPBT MK, 2650 ft/sec at muzzle, 25.0 yds zeroed.

Range (yds) 0.0 25.0 50.0 75.0 100.0 125.0 150.0 175.0 200.0 225.0 250.0 275.0 300.0 325.0 350.0 375.0 400.0 425.0 450.0 475.0 500.0 525.0 550.0 575.0 600.0 625.0 650.0 675.0 700.0 725.0 750.0 775.0 800.0 825.0 850.0 875.0 900.0 925.0 950.0 975.0 1000.0
------------------- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- -----
Bullet Height (in) -1.50 0.00 1.18 2.02 2.52 2.65 2.41 1.79 0.76 -0.69 -2.58 -4.92 -7.75 -11.07 -14.91 -19.30 -24.26 -29.79 -35.91 -42.67 -50.10 -58.23 -67.09 -76.72 -87.14 -98.39 -110.50 -123.48 -137.40 -152.35 -168.24 -185.17 -203.23 -222.48 -242.97 -264.76 -287.85 -312.28 -338.06 -365.43 -394.50

 

[hatfield954]

Thanks men for all of your input. I will use suggestions to try and get things to a normal level. It is a new rifle and setup and different from anything I have used in the past. I will have to spend more time with it, so I can form a bond and get to know it better. This was the first day of shooting it. The trigger pull itself was a surprise. Man that thing has a light pull. If you even think you are in the state of mind to fire, it's already fired.

 

[silvertip-co]

i've found that if i get on paper at 25 yards that i should put the groups between 1-1.5" low at that distance to have them hit close to center at 100 yards. I did the same thing you did but i was shooting a 7mm mag that was dead on at 25 yards and missed the target at 100 yards. I have since learned that in my experience if you keep the poi about 1 inch low at 25 you'll be a lot closer at 100.

yep !