Elevation adjustment on a 1911

[Robk]

Hello, I need some input on this issue I have with an adjustable rear sighted 1911. I am decently proficient with it at normal combat ranges, perhaps to 10 yards. But am having issue with 25 yards, it is shooting low. I believe I may have made a mistake in adjusting the rear sights all the way up. Seeing as in some simple searching, the trajectory for a 230 grain bullet at about 850fps should actually be ever so slightly above target that 25 yards. So did I make a mistake? Should I have just left the sights alone for zeroed at 10 yards and worked from there? any input would be greatly appreciated.

Thanks again,

Rob

 

[cecILL]

Generally, for longer ranges, I just aim higher. Hardly ever move the sights.

 

[45_auto]

Seeing as in some simple searching, the trajectory for a 230 grain bullet at about 850fps should actually be ever so slightly above target that 25 yards.

The height of the trajectory relative to the target depends upon the range that the pistol is zeroed. Since the bullet trajectory is a curved path, if the sights are above the barrel, the trajectory will cross the line of sight (be zeroed) twice, once as the bullet rises through the line of sight and again as it drops through the line of sight. In the real world, unless you are an Olympic class bullseye shooter, these differences are insignificant. Most people zero at 25 yards and call it good.

If you zeroed your 1911 at 10 yards, the bullet will be right on target at 10 yards, right on target again at 20 yards, 0.20" low at 25 yards, and 3.06" low at 50 yards. Chart is here:

http://www.shooterscalculator.com/ballistic-trajectory-chart.php?t=488c97f5

If you zeroed your 1911 at 25 yards, it will be right on target at about 8 yards, 0.08" high at 10 yards, right on target at 25 yards, and 2.64" low at 50 yards. Chart is here:

http://www.shooterscalculator.com/ballistic-trajectory-chart.php?t=8bbd759a

If you zeroed your 1911 at 50 yards, it will be on target at about 4 yards, 0.62" high at 10 yards, 1.34" high at 25 yards, and right on target at 50 yards. Chart is here:

http://www.shooterscalculator.com/ballistic-trajectory-chart.php?t=218a09aa

 

[Bob Wright]

My remedy draws a lot of flak, but works for me. If the gun is hitting low, I place the rear sight about mid height, or a little lower, and file the front sight until I am on target. I've found that zeroing at twenty five yards, using a six o'clock hold on a six inch bull, works best for me over a wide range of distances. When sighted in, touch up the front sight blade with cold blue.

If the gun hits high, file down the rear sight blade.

I had a Colt Gold Cup once (Yes, I have experience with the auto pistol) that so sighted, was deadly on crows out to about seventy five yards, using the 185 gr. Sierra Jacketed Hollow Cavity bullet.

Bob Wright

 

[Boncrayon]

You normally move the rear sight in the direction you want to correct the hit. You may have lowered the rear sight. I have my Desert Eagle 1911 set for 10 yards...that was the setting out of the box. To shoot longer distances, I triangulate the front and rear sight to compensate. If you use your 1911, you'll want to keep it in the 6-10 yard range and compensate for longer distances. I changed to fixed Mepro-Lite tritium sights that glow constantly, even in storage. This is better for night shots.

I'm a proponent of leaving the manufacturer's settings the way they are tested.

 

[tipoc]

Hello, I need some input on this issue I have with an adjustable rear sighted 1911.

What does your manual say?

tipoc

 

[walks with gun]

Not trying to be a jerk in any way, I just went through this with my son in law yesterday, But are you sure you are not pulling the gun down when you shoot, it gets much more pronounced as you increase your range. It's kind of nice to have another good shooter try it before monkeying with the sights.

 

[tipoc]

Good points above.

tipoc

 

[tipoc]

Ok if your gun is zeroed in at 25 yards (this means for either point of aim is also point of impact, or a 6 o'clock hold) with a 230 gr. bullet at 12 yards the round will shoot about .400" of an inch high. Which for most shooters is barely noticeable and not worth concern.

You say that at 10 yards...

I am decently proficient with it at normal combat ranges, perhaps to 10 yards.

Well if at 10 yards you can place all your shots inside a 3" bullseye then there will be no more than a few inches of difference at 25 if at all. But if the gun is shooting low at 10 yards and you have to hold high at 10 to land in a 3" bull, then it makes sense the gun would shoot low at 25.

A fixed sight gun that can hit a 3" bull cleanly at 10 yards can also hit a 6" bull at 25 yards. It would be near impossible for it not to.

If you adjust the sights back so you can hit the 3" bull at 10 yards (draw a 3" or 2" square or circle if you have to) and you still can't land at 25 then it's either the ammo, or shooter or both. Try shooting off a bench.

tipoc

 

[Robk]

Thank you all for the input. As this is an aftermarket site, a Novack Adjustable, the manual is of no help. I think from the discussion, i should try to zero it back to 10 yards and see how that works for me. I may be pulling, but do not think so. As pointed out, it would be nice to have someone else there to critique me. Thank your all the information, I will be sure to look it all over carefully. Now if I can just get back to the range.

 

[Jim Watson]

As 45 auto pointed out, if you zero at such a short range, the trajectory drop is steep farther out. Whereas if you zero at the longest range you can hold a group, the midrange rise is not much at all. I was slightly above center at 50 feet (17 yards) today and that is ample for my IDPA.

 

[rock185]

Hello RobK, regardless of trajectory, ballistics,etc, there is only one sure way to zero your pistol for you personally. Shoot it at the range and adjust elevation, and windage if necessary, till the POA/POI you want is achieved. When I sight in, I shoot from the bench and use a rest of some kind to remove as much human error as possible. Nobody else, no machine rest or whatever can do it for you. No other person, or machine, will grip the pistol exactly as you do, have the same trigger press you do, view the sights exactly the same way you do, etc.

I prefer adjustable sights, and most of my 1911s have them. I don't hesitate to adjust them to achieve the POA/POI I'm looking for. That's what adjustable sights are for after all. I would caution against filing on the sights,especially since you indicate your rear sight is adjustable. Been there, done that. Once filed on a front sight, even though my gun had adjustable sights. Had to have my gunsmith silver solder in a new front and reblue slide. Very unrewarding.....ymmv

 

[T. O'Heir]

"...may be pulling..." Generally speaking, if you can hit the target where you want to at whatever distance, consistently, it's not you.
You do have to know the sight setting for each distance though. Same as you would with a rifle. Sight in at 10, then shot at 25 to see where the thing hits. We'll assume you have a matched set.
This is the Novak sight manual. Adjusting 'em is about half way down. Kind of odd they talk about adjusting and adjustable pistol sight by changing the front and no mention of clicks.
https://www.novaksights.com/Content.aspx?PAGE="Sights 101"
Filing the sight is far too hit or miss. Doesn't take much to file off too much. And filing is for one distance only too.

 

[tipoc]

Robk,

Like you said go shoot at try to get the gun to shoot poa/poi at 12 yards or so with the bullet weight you prefer. If you can do that then you should be good to go at 25 yards for the same.

Like I mentioned before if your gun is zeroed at 25 yards with a 230 gr. bullet it will be good to go at any range less than that (that's why fixed sight guns work). It's called "Mid-range trajectory". If zeroed for 25 yards the bullet rise will be less than half an inch at 12 yards.

If it doesn't do that then it's likely the shooter and not the gun.

You said before that the gun was shooting where you wanted it to at 10 yards but low at 25 yards...how low?

You also said the Novack sights are aftermarket. Who did the install?

tipoc

 

[Master Blaster]

Are you able to shoot a group at 25 yards or are your shots all over the target? It's easy enough to adjust the sights for 25 yards and then try shooting at 10 yards. If you can't shoot a group at 25 yards its probably you flinching.

 

[Aguila Blanca]

Thank you all for the input. As this is an aftermarket site, a Novack Adjustable, the manual is of no help. I think from the discussion, i should try to zero it back to 10 yards and see how that works for me.

Either a 10-yard zero or a 25-yard zero will work for most purposes other than bullseye competition but, overall, the 25-yard zero is better. Take another look at what 45_Auto posted up for your consideration:

If you zeroed your 1911 at 10 yards, the bullet will be right on target at 10 yards, right on target again at 20 yards, 0.20" low at 25 yards, and 3.06" low at 50 yards. Chart is here:

http://www.shooterscalculator.com/ba...php?t=488c97f5

If you zeroed your 1911 at 25 yards, it will be right on target at about 8 yards, 0.08" high at 10 yards, right on target at 25 yards, and 2.64" low at 50 yards. Chart is here:

http://www.shooterscalculator.com/ba...php?t=8bbd759a

Using the 25-yard zero, the deviation at 10 yards is much smaller than anyone can hold (.08"), whereas if you zero at 10 yards the deviation at 25 yards is twice as much (but still better than most people can shoot). And the 25-yard zero is much better than the 10-yard zero beyond 25 yards

 

[44 AMP]

it is shooting low. I believe I may have made a mistake in adjusting the rear sights all the way up.

this is an aftermarket site, a Novack Adjustable

Any chance you have the original rear sight?? So you can compare the height with the new one??

Simply put, if you are out of adjustment and still hitting low at the desired range (and assuming its the gun and not the shooter ) then either the load, or the height of the sights needs to be changed.

Now yes, trajectory is a curve, and the .45 acp is VERY curved, as the distance increases, BUT the difference at short range, between 10 and 25yds is small, smaller than the accuracy potential of most pistols. The drop between 25 and 50yds is another matter.

Having a different shooter try the gun and load (as is) and see what they get. Don't be surprised if they get something different from what you get. Different people look through the sights and shoot differently. More than one additional shooter will help expand the sample. IF a couple of other shooters all shoot low just like you do, or shoot low a different amount than you do its the gun that needs adjustment.

If they get POI=POA then its you that needs adjustment.

 

[RickB]

This is cribbed from another forum:

"With a 230 grain at 850 fps, looks like if you're zeroed at 25 yds, at 50 yds it's 1.9 in. low, at 75 yds it's 6.8 in. low, and at 100 yds it's 14.8 in. low. This is all approx. and is according to Federal."

When I re-zeroed my gun at 50 (carefully, from prone), I didn't notice any change at shorter distances. Not saying it didn't change, just that it didn't change my point-blank range.

 

[ShootistPRS]

Raising the rear sight should raise the point of impact. If you run out of adjustment you can either put a higher blade on the rear sight or file the front sight down (or replace it with a shorter sight).

 

[RickB]

Zeroing at ten yards, other than to make sure the gun is "on paper" in preparation for additional zeroing, isn't going to tell you much; you'll find the elevation and windage errors are often masked by the group size.

I grouped a gun at ten yards, and looking at the group decided it was just about centered . . . until I folded the target in half, and determined that about 2/3 of the rounds had actually hit right of center, and at 25 yards the gun would have probably been a few inches right of POA.