UZI sight-in distances: point blank range analysis
By Alex Nieuwland and JD Lester – Suarez International Staff Instructors
As you can see, the UZI is basically a big pistol. Thanks to its stock, however, even moderately trained personnel can easily push its useful distance out beyond “normal” pistol range, and we therefore need to look at it more like a rifle than a pistol. One of the questions that came up in class recently was: “Alex, what is the best sight-in distance for my UZI?” That is a good question, because a poor choice of zero can have adverse consequences at longer ranges, as we’ll see later in this article.
To answer this question intelligently, we can use a concept that comes to us from rifle ballistics called Point Blank Range Analysis. To determine our point blank range, we must decide what the smallest target is that we are trying to hit, and what ammunition we are going to use. We plug that into a ballistics calculator and calculate at what distance the curved flight path of the bullet will cause us to hit the top and the bottom of the target, while we aim straight at the target.
I chose 4” for the height of the target, because the height of the sights over the bore of the barrel of my UZI is 1.8”, so I will be almost 2” off somewhere along the trajectory. I chose to use Winchester 124 gr 9 mm NATO, because that is the ammunition used by NATO in its UZIs. The Winchester site lists the ballistic coefficient (basically, how aerodynamic the bullet is) of their 124 gr bullet as 0.166. I did not have a chronograph yet, so for my calculation I chose the velocity found by Ballistics by the Inch for a 124 grain 9 mm Luger bullet out of a 16” barrel: 1243 fps.
Plugging those numbers into my NightForce Exbal ballistics calculator yielded a zero point of 92 yards, with hits at the top and bottom of the target at 54 yards and 105 yards, respectively. This shows that, with a careful choice of zero point, I should be able to hold dead-on out to 105 yards, and still hit a 4” high target. Choosing 6.5” (the size of the dot in my RMR at 100 yards) as the target size yielded a zero point of 109 yards, good out to 127 yards. That’s exactly 100 meters, the zero point suggested by the original UZI manufacturer (IMI).
These zero points, however, are all the second intercept of the bullet with the line of sight. I prefer sighting in rifles using the first intercept, before going out to longer distances to verify the zero, because it’s just a whole lot easier. To find the first intercept, I plotted this solution using the ballistics calculator at handloads.com and Microsoft Excel. You can see the calculation for the first solution below. The bullet starts at 1.8” below the line of sight, crosses the line of sight at 15 yards (1st intercept), climbs to about 2” above the line of sight at 55 yards, and then starts to drop, crossing the line of sight again around 92 yards (2nd intercept). Around 106 yards, it is 2” below the line of sight, but by 150 yards, it is already 12” below the line of sight.
I verified this solution at the range. I carefully zeroed my UZI at 15 yards using the RMR, then moved to 50 yards (the maximum possible at this range). At 50 yards, my hits were 2.5” high. Close enough for me.
I also tried 158 gr 9 mm subsonic ammunition with this zero. The slower 158 gr bullets take longer to get to the target, and should therefore drop more at the same range. They did: at 50 yards, the hits were 3” below the point of aim, for a total drop of 5” compared to 124 gr 9 mm NATO.
115 gr 9 mm Luger is a lot more common than 124 gr 9 mm NATO, so I also used Exbal to calculate the point blank range for 115 gr 9 mm Luger with a 0.142 ballistic coefficient at 1295 fps. The calculated zero point was 93 yards, maximum at 55 yards, minimum at 107 yards. For this, a first intercept at 15.5 yards worked better than a first intercept at 15 yards.
For the suppressor-inclined, here is the solution for 147 gr 9 mm Luger with a 0.2 ballistic coefficient at 1073 fps: 83 yard zero point, maximum at 48 and minimum at 95 yards. Note that it was zeroed at 13.5 yards, and note the drop at 150 yards: almost 17”.
The graph below shows what happens if a zero point of 7 yards is chosen with the 124 gr 9 mm NATO load (btw, the zero point distance should be measured from the muzzle, not from where you are standing). The point blank range of this zero point is only about 15 yards. Beyond 15 yards, it is too high according to the 4” target height specifications set earlier. I’d say that this zero is too close, and better results can be obtained by moving it out further.
One issue that has come up while I was doing this, is the difference between UZI iron sights, and RMR sights. There are two kinds of iron sights for UZIs: Model A and Model B. The pictures below shows my Model A sights, and JD Lester’s Model B sights.
The Model A front sight consists of a threaded drum topped by with an off-center front sight post that is screwed into a hole in the receiver. A nut and a lock washer keep the front sight from unscrewing under recoil. The front sight is used for both elevation and windage adjustments. Model B sights have the elevation adjustment in the front sight, and the windage adjustment in the rear sight. The Model B front sight has a detent to keep it from unscrewing under recoil. Each model comes with two flip-up apertures: 100 meter and 200 meter. Each model sight requires a different sight adjustment tool. You can buy the one for the Model A sights here.
JD’s (Model B) front sight is almost bottomed out. My (Model A) front sight is cranked up as high as I can get it without having it pop out of the hole in the receiver, and I was barely able to get a 10 yard zero. A more distant zero would require a longer front sight post. The UZIs currently shipping from Vector Arms are all equipped with Model A sights from Israeli-made UZI parts kits, so we can be reasonably sure that these sights used to work for a 100 meter zero. I’m guessing the difference is caused by the 16 inch “Pinocchio” barrels that Vector has to install to comply with Federal law. If you run into this issue as well, there are a couple of ways out of it: find a longer Model A front sight post (which I have been unable to do), SBR your UZI, or relegate your iron sights to the role of backup sights and install a Trijicon RMR sight.
I went with the last solution. My RMR sight is installed on a TSD top cover and co-witnessed (more or less) with the iron sights. I have filed off the top half of the 200 meter aperture to have a better view of the dot. Be aware that parallax error (how high the dot appears to be in the RMR) can affect things as you are sighting in the gun. I use the lower half of the aperture to minimize this source of variability. Eventually, I will blacken the exposed metal to lessen the glare of sunlight reflected into my RMR sight.
So, the complete answer to the question at the start of this article is: “That depends on your ammunition, the maximum difference between the point of aim and point of impact that you find acceptable, and your sights.”
The easy solution, in my opinion, is to go with 124 gr 9 mm NATO, a TSD top cover with RMR (whenever they become available again) and a 15 yard zero.
Care to comment? You can do so in this thread on WarriorTalk.