Why do i have to aim my 1911 low at 50 yards

[Classic]

Somewhere I have seen a side view showing the various target distances and the "rainbow" shaped path the projectile takes and the height difference at each range. When I saw the drawing I finally understood.

 

[Classic]

Here is a Pic

Bullet path drawing

 

[45calibre]

sights are generally set to shoot point of Aim at 25 yards. as they are above the barrel you must tilt the gun up,( measure the slide to top of front sight, and slide to top of rear sight) by having a shorter front sight than rear sight. As the standard handgun round doesn't drop much between 0 and 50 yards this slit tilt up, means you are "pointing" the bullets path above the point your sights are aiming at.

http://www.google.com/imgres?imgurl...6-sTv2WG8L00gGM0vmeDw&ved=0CEsQ9QEwBA&dur=199 look at this, imagine your pistol is Zeroed at 50 yards, the bullet will continue to rise until 100~ yards. SO to hit where you want to, you need to compensate for the bullets flight path. Thus you need aim on at 50, low at 100, on at 150, then compensate for drop past 150. of course that bullet path chart isn't for .45 acp. but the logic is sound.

ok so if i understand this correctly the OP has to aim low at 50 yards because the bullet is still rising from the muzzle up to the point of 50 yards?

 

[iChokePeople]

ok so if i understand this correctly the OP has to aim low at 50 yards because the bullet is still rising from the muzzle up to the point of 50 yards?

Or hasn't yet fallen back to the point of aim, depending on how the OP's sights are set up.

If anyone doesn't get it, I can draw it out and probably make it clear, if you like.

 

[rvb]

The effect is less noticable w/ an iron sighted pistol at relatively close range (eg 25 yds and under), so many people don't even think about or realize there is a ballistic path.

Shoot something with a scope set way up over the bore (2-2.5") and it becomes very obvious. For instance, my open gun w/ red dot and a 125 gr .355 at ~1375 is zero'd at 10 yds. It hits like 6" high at 50 yds, about 9" high at 75, and doesn't even start coming back down until about 100 yds. Yes, I put in the time learning my holds and shooting groups at those distances.

The difference is for a 10 yd zero, the barrel is angled up is much steeper to hit 2.5" above the bore, where if the iron sights are only ~3/4" above the bore, it's "relatively" flat.

The farther you need to hit, the bigger the arc needs to be, just like throwing a baseball.

Also note that w/ a big arc, you'll usually have two zeros, one close and one when the bullet comes back down. On my pistol mentioned above, the secondary zero is somewhere around 150 yds (not confirmed). On an AR, a 200 yd zero is common, which means that it is also zero'd somewhere around the 50 yd range (300/25 is common also).

lobbin rocks really fast is all we're doing

-rvb

 

[45calibre]

is this very dependent on the cartridge and barrel length?

 

[rvb]

is this very dependent on the cartridge and barrel length?

That's a bit of an oversimplification... velocity and sight height above bore are the easiest factors to understand. Lots of other variables like ballistic coefficient (based on bullet diameter and shape), air temp/humidity/etc, angle of shot, etc.

you can play with any of the free ballistic calculators on line to help get an understanding.

-rvb

 

[slow1911s]

^ excluding the rise in the middle of shooting and it hitting the ground?

It only rises if it is pointing up, of course. Even then, compared to the angle of the barrel, the bullet is always falling. The bullet isn't falling when it hits the ground - it has fallen.

 

[sv40sw45]

Is the barrel fit correctly? Do the primers have the firing pin hit in the center of the primer? If the barrel is fit correctly the line of sight is paralell to the bore of the weapon, it is not fit correctly it will be out of paralell and shoot high or low the farther away the targets is.

 

[DIM TIM]

Glad I came here. A few of these posts explain a lot of what I had a few questions about. Thanks guys.