By now, we as an industry have had the opportunity to play with a variety of zeros. Some things have changed, others have not.
Max effective range
Something that hasn’t changed is being able to define your mission. What do you intend on using your rifle for, like specifically the range to target. Most everyone these days is using the 5.56mm rounds so with that being my base I see as the maximum effective range for that caliber about 300m. Anything past that is a bonus, but I need my gear to be optimized to hit at that range and closer. I would also comment that most everyone is using a red dot optic of some sort and while I can hit known targets at ranges further than that, my ability to locate and identify without the aide of magnification is limited.
Putting aside marksmanship skills for a second and assuming they are dialed in let’s spend the rest of the blog talking about zeros. I’m going to make this quick, if you are using a 50m, 100m, or 200m yard zero you are good to go. If you are going with a 25m or even the 300m zero you need to seriously reconsider and here’s why.
Point blank range
For the most part we want as flat a trajectory for as far as possible. How far is far, that’s a trick question because what I’m really talking about is Point Blank Range. We define the PBR as the furthest range before I have to compensate for my bullets flight path. For combat effectives we define 8 inches as our target zone, so if I aim in the exact center I have 4 inches high and low of trajectory. When my trajectory exceeds 4 inches I’ve exceeded the point blank range.
The hard truth
With 300m as my target range I will see the 25m zero peter out at 75m. Probably the worse zero you could have for a fighting rifle. Then the 300m zero peters out at 150m. What that means is while I will hit at 300m there are closer ranges where I could do everything correct but my trajectory misses because I’ve exceeded my point blank range, again not good for a fighting rifle.
It’s really personal
When you look at the three most common; 50, 100 and 200 they all have great performance out to 300m. One might be slightly better on paper, but the reality is the shooter is not going to see a couple tenths of an inch at 175m. If you could then you would already know this material. The bottom line is your choice is really more about personal preference over anything else, then for some its what their favorite instructor is shooting. My recommendation is to shoot all three, learn them inside and out then figure out which you like the most.
What I can’t stand
One of my pet peeves is those who believe the 50m and 200m are the same. Again, reference my early comment about being able to see a tenth of an inch at some of the ranges. However, while it may say that on paper, it is a completely different ballgame in reality. I know it seems obvious, but there is 150m of difference between the two, which means a lot of room for shooting errors. Just because you’ve shot a 50m zero don’t make the mistake thinking you will hit at 200m. You might, but our observations with students are much different.
One might argue the further zeros are more challenging and I would definitely agree. You first need the distance, which is not too common these days. Then you need the skill, some have it at 50m, fewer at 100m and even less at the 200m. We use MOA as our evaluator as I’m sure most do on their own. If you can hold sub-4MOA at 50m, then you should be able to hold the same at 100m and the same at 200m for a pretty well rounded rifleman. Of course, we’d want the tightest groups possible, but that can be a slippery slope leading to gear and equipment changes that might not be the best for combat/practical.
The bottom line is I don’t give a hairy rat’s ass which of those three you use as long as you hit consistent. That’s the true mark of a rifleman.
"The primary job of the rifleman is not to gain fire superiority over the enemy, but to kill him with accurate, aimed fire." Former Army Cheif of Staff Joseph "Lightning Joe" Collins