View Full Version : Maybe a dump question but here goes

12-04-2011, 7:47 PM
I was out shooting my ar(.223) at the range. I just built and I have a red dot on it a 1x30. I sighted it in at 25 yards and shoot really good pretty much dead on . Then move the target to 50 yards and it shot 5 inches high or so. My plan was to shot at targets at 15-50 yards or so maybe farther . Am I going to have to choose certain yard , to say 30yards and keep it there.?

12-04-2011, 7:52 PM
The red dot is maybe 1" to 2" above the borecenter.

If you put a paper at the end of the gun and sight using the red dot, you'll have a hole 1" to 2" low from POI (point of aim).

So, when you are aligning at 25' you are compenstating for this parallax.
As distance goes to infinity, this error goes to zero.

Bottom line, sight in at 50 yards and you'll shoot slightly low at both 25 yards and 100 yards, but right on at 50 yards. At these ranges, bullet drop is almost nil.

If you sight in at 25 yards, you'll be high at 50 yards and even higher at 100 yards. I would have guessed 1" high at 50 yards and 2-3" high at 100 yards.


12-04-2011, 8:12 PM
Ok that answer my question . I really like my red dot and dnt. Plan on a scope yet. My propose for this rifle Is range shooting and every now and then we walk my buddy orange grove and take out huge jack rabbits and some time call I coyotes and if I get them in to say 50 yards or so I can take the shoot anything farther my buddy has a dead on t.c contender. Farthest shoot I want to do is 100. I had this sighted in at 25 and shot at 100 yards and didn't hit an 12 circle lol . But I was working on it getting it set at 50 yards before the range closed today.

Dreaded Claymore
12-04-2011, 8:22 PM
Okay, look at this highly detailed technical drawing I made. :D
The black line is the alignment of your sights. Any point along this line will appear to be dead in your sights, whether you're using a red dot sight, a telescopic sight, or iron sights.

The red line is the trajectory of the bullet, approximately a parabola. The straight line of your sights will usually cross the trajectory of your bullet at two points. That's why you'll sometimes hear of rifles being sighted in at "50 and 200 meters," or something: those are the two distances at which your sight line intersects the bullet's path. It means that if the target is fifty meters away, you'll hit it dead on if you aim right at it; if it's one hundred meters away, you'll hit a little bit high; if it's two hundred meters away, you'll hit dead on; and if it's two hundred fifty meters away, you'll hit a little bit low. You can see why from the picture.

12-04-2011, 8:26 PM
lol dyslexic with the b and the p i see

Dreaded Claymore
12-04-2011, 8:57 PM
Just re-posting what D-Claymore had done...

Thank you for showing me how to do that. :thumbsup:

12-04-2011, 9:06 PM
Thanks guys the drawing great lol I'm a visual person so by looking at what I'm reading helps out .