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Posted: 6/9/2006 6:11:41 AM EDT
| I have zeroed my m4gery in a 25 yards at the range and it shoots dead on. I am using SPOT MKIII red dot sight (Aimpoint clone). I moved out to 50 yards and I was about 2 inches high. Now I know there is definite bullet rise but is that normal?? One thing I have notced at the range I shoot at is that the center of the target board at 25 yards is definitely above the top of the shooting benches meaning that I am probably centered at 25 yards but shooting up at the target as opposed to being level with the target to begin with. Any thoughts |
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The Bullet does NOT rise when it leaves the barrel...But you knew that. The weapon fires the bullet in an arc determined by the point of impact you have adjusted your sights for. I'm only speaking in general terms everyone, off the cuff...give me a break. Sighting in at 25 yards provides an approx. target zero (impact) of about 300 yards. So, your bullet is fired up into the air (due to your sight adjustment), then falls back to the target. A. The top figure is your bore alignment when using sights.. B. The bottom figure is shooting the weapon with the bore "Parallel" to the ground without using sights. Both show the affect "gravity" has on the bullet. http://img322.imageshack.us/img322/5505/bore2dd.png |
| because the ar15 sight's are a couple inches above the bore, and if you're zeroed for 25 yards and you drew a line from your sights to the target and a line from the bore to your target, the line from your bore would have to be going upwards in order to converge with the flat line from your sights. thus, the bullet is rising |
The scale of the chart is compressed so it looks a bit funny and this is a comparison between zeroing at 50ys with the irons (2.6" above bore axis) and a std handle mounted scope (3.6" above bore axis), but it gives you an idea of the actual trajectory of M-193 ammo in an AR.
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Ok I guess I my haste to write I wasn't real clear on my question. First I understand that the bullet doesn't rise that there is a natural arc due to gravity etc. I guess I was surprised that there was such a difference of being dead on at 25yds and over 2" high at 50yds. The way the shooting benches and targets are setup gives the feeling of shooting up slightly unless you stand or use a high bench rest. I wasn't sure if that had any affect on zeroing. I went to the range today and zeroed at 50 yards. Didn't get a chance to test at longer ranges however. |
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I'm glad you understood what you were talking about AZA2. Sorry to butt in. I just wanted clarity in the issue. You should be careful how you use "BULLET RISE" in a conversation. The un-informed may take that to mean a bullet actually rises when fired from a weapon. "BULLET TRAJECTORY" is closer to what you are talking about when zeroing/firing a weapon. The term "Bullet Rise" is an accepted term that can be mis-understood if not used correctly. A Bullet will not "RISE" above the bore (angle) of your weapon. A Bullet may/will "RISE" above your Sight Plane due to the angle of your bore. Prove this wrong and win a Nobel Prize... "The Law of Gravity" has been SUSPENDED until further Notice.... hort |
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