In discussing the "need" for an AR 15 in another thread, it brought to mind I recently zeroed my Savage MSR Recon with a new Vortex UH-1 sight and I'm curious what distance others zero their AR 15 rifles (36 yards? 50/200 yards? 100 yards?). I did a quick zero on mine at an indoor range. I wanted a 50/200 zero, but my indoor range doesn't go to 50 yards, so I recalculated at 10 yards. For my setup (2.85" above bore scope shooting 62 gr. .223/5.56, I figured I should be about 1.9" below point of aim at 10 yards. Hopefully I'll get a chance to hit an outdoor range soon to validate that. The 50/200 yard zero seemed to be one of the more popular zeros, but I'm curious if others zero differently.
I like the 50/200 zero also. Anything from 0 yards to about 250 you can put your sight on the target and hit within 2 inches of your point of aim. You're probably right on the money being just shy of 2 inches low at 10 yards. Should be about 1.2 inches low at 25.
I zeroed mine at 50yrd also. I put a 3x prism scope on it. I originally had a 1x prism scope on it but didn't like it. I zeroed by PCC (CZ scorpion pistol with brace) with a 1x prism scope at 25yrds.
He calculated where the POI should be at 10 yards based on a 50 yard zero and adjusted to that. he assumed that adjusting his sights to hit 1.9" low at 10 yards will result in a 50 yard zero based on ballistics charts/calculation. Personally I would have gone with a 25 yards instead of 10, but it definitely still needs to be checked on a longer range. It will be plenty accurate for home defense situations though.
mrhutch is correct - I zeroed for 50/200 by setting the point of impact 1.9" below the point of aim at 10 yards (based on the height of my scope above the bore axis). It is only a rough zero at this point.
What is the purpose of this rifle? I think I would answer that question and then select a zero distance.
Well, I don't think that a bunch of thugs will break into the house (at least I hope not), so the reality is that this will be a range gun. The Vortex site does include a second aim point in the reticle for ~10 yard shots when engaging closer targets.
Where is your location? What is around you? What are you going to destroy and or terminate? How much training have you had at these ranges? How consistent are you at these ranges? How will you handle the stress of being under fire? Is it dark-night / light of day? How many perps / attackers? How many shots to confirm a hit? (refer to night) How many magazines are actually available at in an emergency situation? I think the math is impressive. knowing your weapon is crucial. Personally I think 250 yards is a good range to shoot for, (no pun), unless doubling your weapons duty as providing food on said table. IF you become proficient enough, 100 to 350 yards is doable for both rapid response and calculated termination.
I've always been an advocate of a 36/37 yard zero (or maybe 35 meters). It always seemed to keep the bullet within a few inches either above POA out to any reasonable distance. Unfortunately no scope I have has aiming points that match.
Most zeros will allow you to maintain a ~5" radius from POA between roughly 250 - 350 yards. Some zeros (eg, 50/200) can tighten that radius up. The outlier is a 25 yard zero which has a bigger apex. This is for combat shooting, not match shooting. You might find these articles interesting. I don't like to reinvent the wheel. 55 grain bullet trajectories: https://www.ar15.com/content/page.html?id=659 75 grain bullet trajectories: https://www.ar15.com/content/page.html?id=660
I know that some really like the 36/37 yard zero, but it always seemed like to me that the 50/200 had it beat until you're at distances > ~270 ft. If I had a 1-6x power scope on the rifle then I may actually be ale to see out that far, but with my 1x holographic, I don't think I'll be going out that far. Yeah I got a trajectory graph for the American Eagle .223 62gr. that I'm using. Until my rifle skills improve, I will just have to take the manufacturer's word for it.
Unless I have a highpower rifle match scheduled, I kept my AR's zeroed for the longest possible "point blank range" where a dead-on hold keeps the bullet within 4" of the aiming point. I forget exactly where the first and second zero points were, and that probably depends on the load the barrel length and the type of sights or optic the gun has. But it was only good for a couple hundred yards. I do 99% of my shooting of such rifles at 100 or 200 yards. So that's where I want my zero to be. And with a round like the 223 and the bullet zipping along at over 3000 ft./s from the muzzle, the difference between the impact points at 100 yards and 200 yards is almost insignificant.
This is an interesting article about battle sight zero. Saw this on Greg Ellifritz's newsletter. https://robarguns.com/blog/2013/11/24/battle-sight-zero-bzo-who-has-it-right/
Reading that pretty much convinces me that a 100 yard zero is best for what most of us would do with a self defense rifle.
If you are outside of a larger city area, you might want to go to 200 yards. Nemo https://www.washingtonexaminer.com/...1-democrats-see-violence-next-in-war-of-words
In reading the article, the only thing it really says about the 100 yard zero is: I think the real issue with why someone chooses the 100 yard zero over the 50/200 is that for any distance between 50 and 200 (with the 50/200 yard zero) your shots are going to be a little high (a couple of inches). Shooters seems to be a little more comfortable with holdovers vs. hold-unders, so they don't like to hold-under (aim below desired POI) for shots. I can see where the 100 yard zero may be desirable on hunting rifles with scopes that have a parallax set at 100 yards by default, but even then it would depend on where you're hunting - if you're likely to be taking ~ 300 yards shots, your not going to want to hold over the 10+ inches when you could have simply zeroed for a greater distance like 200 or 250. I think seals use the 100 yard zero for CQB operations because of the flat trajectory from CQB to 100 yards and some spec ops people even go for a 36 yard zero. If I had just a red dot reticle, I might consider a 100 yard zero too as the likelihood of shooting > 100 yards for this rifle is pretty low, unless I find a good range to shoot at. However, with the Vortex optic on it, the reticle includes a CQB point of aim marker, so I really don't have to think about the hold-under for shots in the CQB range.
So all the antifa froggyness we've seen over the past four years isn't considered to be violence? What are they? A quilting club? Anyway, all the zeros mentioned get you well into 200+ yards.