Guidance for zeroing - convergence?

[GJM]

Almost every centerfire rifle I have is zeroed for 200 yards, my drops are based on a 200 yard zero, and many of my scopes have a 200 yard center with holdovers for distance. 50/220 simplifies things for me, but ultimately this vs a 100 yard zero is personal preference. For the same reason, my shotguns and PCCs are zeroed at 25/75 — it keeps things common and thus simple for me.

[texasaggie2005]

I've always found Jack Lebua's "Zen of the 100 Meter Zero" a persuasive argument.

https://www.m4carbine.net/showthread...100-Meter-Zero

[shane45]

I understand what your saying. But the arc is the same no matter where you zero. So essentially you are picking your dispersion. 50/220 splits the arc. 100 yd zero is all down. Splitting the arc to live within the dot size and minumise dispersion from poa makes sense to me. (Replying to Rob)

[entropy]

This is one of those online “discussions” that never ends. Pick your flavor, press on. I have found that using an app such as Ballistic allows you to play around a bit to find the best zero for the particular load you are using. If you use a generic zero, it becomes a “one size fits all” issue that may work well if you have a rifle or two and limit your loads to a single factory round or two. When you start dealing with multiple guns and ammunition, it becomes more complicated. What I’m presently doing is zeroing the rifle with the chosen load, then taking a downsized copy of the drop card off Ballistic and either sticking in the grip, or keeping it with the rifle. Most of my dedicated bolt guns have stock packs with drop cards in them for reference. ARs have it tucked in the grip. I’ve scribbled basic zeros on tape as well and applied them to the stocks....

[okie john]

100 here as well. I don't want to think about whether I should be holding over or under, and for any distance I'd be shooting an AR (and well over any distance I can conceive of a justifiable defensive shot) I'm within ~2.5" of total potential deviation. 50/220 gets you a potential total deviation of 5" (2.5" low, 2.5" high) which is more than I want. with a 100 yard zero I put the dot on the target and press the trigger and know that I'll be within 2" (assuming I can actually shoot) out to any distance I consider reasonable/realistic, and for anything at indoors range I know some basic holdovers but even then putting 28 rounds into a spot 2.5" low is probably going to achieve my desired result.

Incidentally, if you decide to go 50/200 or 50/220 or whatever, if all you do is confirm POA=POI at 50, then all you really have is an initial zero confirmation at 50. IMO 90% of the reason that "zero" gained popularity is that people that can't shoot are looking for the shortest distance they can get POA=POI and feel like they can claim some sort of tactical righteousness. If you ever actually go shoot at 200 you may get yourself a surprise. But if that's the way you decide to go, you should get an initial intersection at 50, then a true zero at 200, and then test your holds at 7, 25, 50 & 100 (at a minimum).

I kinda think of the "get a 50 yard initial intersection and quit" as the "barfcom zero".

In my experience, you will definitely get yourself a surprise at 200 if you do this.

Always check your work as far as you plan to engage anything. Ammo doesn't always group as well as expected as range increases. Drops can be greater than expected. Maybe wind will move your group around. Maybe your reticle covers up a lot more target than you thought it would. Maybe you're just a crappy shot and you need to hold your fire at ranges beyond 50 yards for liability reasons.

That can happen no matter where you zero. Always confirm and verify your POI as far out as you plan to engage anything, then make notes and learn to live within your limitations.


Okie John

[frozentundra]

I'm not sure it matters as long as you don't use 25. Just pick either 100 or 50/2xx and know your offset inside 25. Then practice at distance if you want to be able to hit at distance with any given load.

I've used a roughly 200 yard zero on most centerfire rifles for most of my life. It's a habit that's worked afield, so I just stick with it.

I find a 50/2xx to work better for shooting coyotes at unknown distances with .223/5.56 outside of a square range. I've haven't found the slight rise in trajectory between 100-200 to be detrimental for hitting these relatively small, sometimes quick, moving targets. If it works on coyotes in the field, it would probably work on villains too, I suppose. This is mostly with LPVOs, but I just keep it consistent with red dots out of habit.

I'm certainly no world class shooter, but my preference is to zero windage at 50 yards regardless of elevation zero. Then I drag it back as far as I can to confirm what happens at various distances. Windage shouldn't really be changing outside of optical parallax errors. I cant remember ever being too surprised by the outcome. I have occasionally been quite surprised by inconsistent groups or POA/POI shift with various different loads, but that is a different problem than zero scheme.

[Casual Friday]

I've always found Jack Lebua's "Zen of the 100 Meter Zero" a persuasive argument.

https://www.m4carbine.net/showthread...100-Meter-Zero

Indeed. I have messed with different zeroes over the years and always go back to the 100m zero. When I started shooting 11.5" guns full time, I played with a 25, 36, 50/2hundredsomething and came to the conclusion that I prefer 100m zero no matter the barrel length.

[Doc_Glock]

I am no expert but I do prefer the 100 yard zero for all the reasons listed above, and also the added reason: if I miss or don't estimate range properly, the miss will typically be low with the potential to skip the bullet into the intended target and visually evident.