2013 Shooting Low Even With Sights Down

[tomcatt51]

I have Magpul's (Not PTS) on mine and I had to drop the front sight post quite a bit as well, maybe 2.5-3 turns. I was surprised it needed that much, but I'm only on a 25 yard range, so that may be part of it. 25 yards is about as far as I can see anyway lol.

The high sight line does some things most aren't used to. With the usual hi-velocity ammo an 18 yard zero will have you hitting at 100 yds.

 

[Smitty Wesson]

Have a jolly good time with your 15-22. On any gun with an adjustable rear iron sight, move the sight in the direction that you want the shots to move to. To move shots up, move the sight elevation up; to move shots down, move the sight down. To move shots right, move the sight right; to move shots left, move sight left. On a gun with adjustable front sight, it works in reverse. To move shots up, move sight down, and so forth.

 

[cyphertext]

The high sight line does some things most aren't used to. With the usual hi-velocity ammo your 25 yard zero will have you hitting high at 100 yds.

Not according to the Winchester Ballistics calculator, or my own shooting. I put the sight height as 2.6 in., standard AR height, set wind drift at zero, and set temp at 69 degrees. I selected three common rounds from Winchester, and you can see the results below. The first column is the distance, and the third column is drop. This goes with my own personal experience, on at 25, high at 50, back on around 70, and low at 100.


Ballistic Calculator
Ballistics | Winchester Ammunition Ballistics Calculator & Ammo Ballistics

Simulated Shooting Conditions

Sight-in Range: 25 yds Max Range: 100 yds
Cross Wind: 0 mph Temp: 69 F
Altitude: 1000 msl Sight Height: 2.6 in

22 Long Rifle 36 gr. Xpert Lead Hollow Point
Ballistic Coefficient: 0.084 - Muzzle Velocity: 1280
DISTANCE TIME ELAPSED LINE-OF-SIGHT DROP WIND DRIFT VELOCITY ENERGY
0 0 -2.6 0 1280 130.84
10 0.02 -1.4 0 1226 119.97
20 0.05 -0.4 0 1177 110.62
30 0.07 0.2 0 1134 102.7
40 0.1 0.7 0 1096 96.01
50 0.13 0.8 0 1064 90.35
60 0.16 0.7 0 1035 85.5
70 0.19 0.2 0 1009 81.28
80 0.22 -0.6 0 985 77.55
90 0.25 -1.8 0 964 74.21
100 0.28 -3.4 0 944 71.18

22 Long Rifle 40 gr. Wildcat Lead Round Nose
Ballistic Coefficient: 0.1384 - Muzzle Velocity: 1255
DISTANCE TIME ELAPSED LINE-OF-SIGHT DROP WIND DRIFT VELOCITY ENERGY
0 0 -2.6 0 1255 139.75
10 0.02 -1.4 0 1223 132.69
20 0.05 -0.5 0 1193 126.24
30 0.07 0.2 0 1165 120.4
40 0.1 0.7 0 1139 115.12
50 0.13 0.9 0 1115 110.37
60 0.15 0.8 0 1093 106.07
70 0.18 0.4 0 1073 102.19
80 0.21 -0.3 0 1055 98.67
90 0.24 -1.3 0 1037 95.45
100 0.27 -2.6 0 1021 92.5

22 Long Rifle 40 gr. DynaPoint®
Ballistic Coefficient: 0.1486 - Muzzle Velocity: 1150
DISTANCE TIME ELAPSED LINE-OF-SIGHT DROP WIND DRIFT VELOCITY ENERGY
0 0 -2.6 0 1150 117.35
10 0.03 -1.4 0 1127 112.69
20 0.05 -0.4 0 1106 108.47
30 0.08 0.2 0 1086 104.63
40 0.11 0.6 0 1068 101.13
50 0.14 0.7 0 1051 97.93
60 0.17 0.4 0 1035 94.98
70 0.19 -0.2 0 1020 92.26
80 0.22 -1.1 0 1006 89.73
90 0.25 -2.3 0 992 87.36
100 0.28 -3.9 0 980 85.15

 

[cyphertext]

Tom7171, here is what I am going to do next time at the range.

I am going to re-zero for 25 yds, with the rear dial set to Z. I am assuming that there is enough adjustment in my front sight to support this.

Once zeroed for 25 yds, I am going to move to the 50 yrd line. With the 25 yd zero, I should be high, and will shoot to confirm. Then, I will move the rear sight down to the 5/3 setting, bottoming out the sight. I am hoping that this will give me enough adjustment to get on at 50 yds. If not, will have to go back to 25 and re-zero with the rear sight higher.

If it does give me enough adjustment, then I will move to 100 yd line and move the rear sight up, past the Z, and experiment from there to see how many clicks past Z will put me on at 100.

 

[tomcatt51]

Not according to the Winchester Ballistics calculator...

Yes, brain fade, but we're splitting hairs. An 18 yd zero puts you on at 100 yds assuming a 40 gr bullet @ 1250 fps with a .12 BC and a 2.6" - 2.7" sight height.

With a 25 yd zero you make a less than 3 moa sight change to be on at 100 yds. That's a 3/4" change in your group center at 25 yds. How many can shoot good enough groups to to find a 3/4" change?

I corrected my post.

 

[cyphertext]

I made it out to the range and was able to try my theory. I am shooting a CMMG Quebec A with the rear sight from a M&P 15-22 and a front sight that is similar to the stock 15-22 sight, only taller as the "gas block" rail was not on the same plane as the receiver rail.

I was able to set the 25 yard zero at the Z setting on the rear sight. The front sight had enough adjustment, although I think I would like to get a taller pin, just so that more of the threads are down in the sight.

After zeroing at 25 yards on Z, I moved to the 50 yard line and moved the sight 3 clicks down to the 5/3 setting, bottoming out the sight. This did put me on at 50 yards.

I then turned the dial to raise the rear sight, past the Z to the 4 setting and attempted to shoot at 100 yards. By this time, the front had moved in and there was a pretty good breeze blowing across the range. I was hitting high and to the left. Also, the front sight pin appeared as wide as my target, so I would like a thinner front sight post for shooting at 100 yards. Plus my eyes are not what they were in the past. Sometimes I had trouble just keeping the front sight in focus.

As a side note, the bargain bin Bushnell Trophy multi-reticle red dot that I picked up from Cabela's is really fun to shoot with!