Advanced Site Zeroing Tricks

[Sanch]

What are some advanced tricks and tips to zeroing carbine sights? Let’s not limit this to AR15s necessarily, but that’s what I’m mainly interested in.

First question: can an upper be put on any lower and have the same zero set? Are zeros interchangeable when switching uppers to different lowers?

If so, then maybe zeroing with a lower that has a lighter weight competition trigger like the SSA-E would be beneficial even if the lower assigned to a particular upper has a GI trigger which would make zeroing less precise.

Also, if someone has an AR pistol without a full buttstock, perhaps if the person also owns an SBR, you can put the pistol upper on the SBR lower to zero it with a more significant buttstock.

I recently learned about foam wedge blocks that look like yoga blocks but with triangles cut out. That seems like it could come in handy to zero. Maybe with a precision shooting sandbag for the rear.

In the past I’ve always zeroed ARs using the lower it was assigned to, from prone, without any kind of support. I feel like if I can temporarily swap things around, I could get a more precise zero.

[Sanch]

Other topics/questions:

If you zero a 5.56 AR using a 25/300 or 50/200 zero, I’ve heard some claim on the internet that they like to do the initial zero at 25 or 50 and then confirm it at 200/300 when they can take it out to distance and adjust as needed. I’m wondering how plausible that is to use a 2 MOA red dot at 200 or 300 yards, coveting 4” or 6” of the target, respectively to make small enough groups to refine a zero at distance. Now that I’m learning more of shooting, I’m calling bullshit here but open to the possibility it’s a legit thing.


Are some people doing custom zeros? Like an 87 yard zero or something fancy, where for their intended purpose, they get a flatter trajectory within that narrower set of distances? Any thoughts on these kinds of non-standard zeros?


Are people DOPE-into their red dot carbines, or are they plugging barrel length and round into a calculator program to find trajectory? I assume people don’t bother with actual DOPEs since the application of a red dot carbine doesn’t make much sense for for that. Do you really need to know the holdover is 3.5 inches at 185 yards? Or do you just put the dot on the target out to 200 and call it good enough? And the. Possibly memorize the holdovers for 300, 400, 500, 600 for 5.56 out of your gun, in the event of some crazy shot you need to make with nonmagnified red dot? Which holdovers outside of zeroing range (200 or 300) do you find useful to know?


Do you zero for “duty” loads like 62 gr soft point or 75 grain TAP, and then shoot cheaper 55gr FMJ to learn offsets with that cheaper practice round? And then if taking a class, you apply those offsets as needed for longer shots?


Is it possible to zero the gun for duty ammo, then shoot cheaper 55gr FMJ, identify the exact zeroing adjustments, say it’s 5 clicks down and 2 clicks right. Then for a training class, dial those adjustments into the aimpoint. And when done, dial the same ones backwards, and would that return you to the zero for the duty rounds? I assume this should technically work, although I also assume that most classes for carbines are 90% out to 50 yards or less, and 10% of the class might be 100 yards, due to logistics of open enrollment classes lacking access to longer ranges and open enrollment student base not interested in 200 yard carbine shots.

My point being, I’d bet it would work to temporarily adjust the aimpoint zero with a note on how to revert it without shooting any duty ammo, however the offset is likely irreverent to the average open enrollment class. Although, the effort seems fairly low, if it technically works. Show up to the class with the gun zero for duty ammo. During the zero portion of class, shoot the cheaper ammo. Take good notes on how many clicks you made. And then revert later at end of class.


With ammo availability being touchy, I wonder if I can identify the five different commonly available 5.56 cheaper 55gr loads I buy. Like I used to get magtech but that dried up and now it’s X-tac. And I wonder if I can take the effort to record the zero differences compared to the baseline duty loadout. So the gun stays zeroed for the duty ammo. And if I can find magtech then I look in my notes where 3 years ago I had identified the zero difference is 7 clicks down and 2 clicks left relative to the duty ammo zero. And then not even need to take the effort to zero it, just dial those clicks I previously identified. Or maybe the different lots of non-match grade ammo are so different over time, it won’t hold true?


As I’m getting more into carbines, I realize there’s the potential for some interesting ideas beyond the basics of zeroing.

Do any of these ideas have merit? What advanced zero techniques do you use?

[UNM1136]

If you zero a 5.56 AR using a 25/300 or 50/200 zero, I’ve heard some claim on the internet that they like to do the initial zero at 25 or 50 and then confirm it at 200/300 when they can take it out to distance and adjust as needed. I’m wondering how plausible that is to use a 2 MOA red dot at 200 or 300 yards, coveting 4” or 6” of the target, respectively to make small enough groups to refine a zero at distance. Now that I’m learning more of shooting, I’m calling bullshit here but open to the possibility it’s a legit thing.

I think you need to define purpose. If you are a bench rester/Camp Perry type I suspect you are right. General/defensive use 50/200 is just fine for me and the couple of hundred officers I work with and/or have trained. I have wrung my 6920 out at 717 yards, then the farthest steel I could shoot at my old range. I have always used a 50/200 zero, with a 2 MOA Aimpoint or an Eotech (although the Eotech, while having the superior reticle was given up about a decade ago). I know my holdovers/offset, and have learned to use my 2 MOA dot for rough range estimation. My purposes are to shoot minute of felon. Your purposes may be different.

pat

[TWR]

I know a guy that shoots Camp Perry and he beds uppers to lowers and found very minimal benefits at 300 and beyond but for most of us, a zeroed upper will still be zeroed on any lower.

Red dots and bullseye shooting don’t mix. I zero 50/200 and confirm at 200. I center the group and make hits just fine at 300 knowing my holdovers.

I mainly shoot 77 grain SMK’s and that’s what I zero with. At closer ranges I can get acceptable results with M193. Scoped guns are different and zero’s are better defined, I shoot the ammo they’re zeroed for.

I’m not a bench rest shooter, hate it actually. I hunt and shoot steel.

[Wake27]

What are some advanced tricks and tips to zeroing carbine sights? Let’s not limit this to AR15s necessarily, but that’s what I’m mainly interested in.

First question: can an upper be put on any lower and have the same zero set? Are zeros interchangeable when switching uppers to different lowers?

If so, then maybe zeroing with a lower that has a lighter weight competition trigger like the SSA-E would be beneficial even if the lower assigned to a particular upper has a GI trigger which would make zeroing less precise.

Also, if someone has an AR pistol without a full buttstock, perhaps if the person also owns an SBR, you can put the pistol upper on the SBR lower to zero it with a more significant buttstock.

I recently learned about foam wedge blocks that look like yoga blocks but with triangles cut out. That seems like it could come in handy to zero. Maybe with a precision shooting sandbag for the rear.

In the past I’ve always zeroed ARs using the lower it was assigned to, from prone, without any kind of support. I feel like if I can temporarily swap things around, I could get a more precise zero.

I’ve never noticed a difference between lowers. I try to minimize the types of triggers I have but everything is typically zero’d with an Atlas bipod, rear sandbag, full stock on an SBR lower if needed, and SD-E.


Sent from my iPhone using Tapatalk

[Wake27]

Other topics/questions:

If you zero a 5.56 AR using a 25/300 or 50/200 zero, I’ve heard some claim on the internet that they like to do the initial zero at 25 or 50 and then confirm it at 200/300 when they can take it out to distance and adjust as needed. I’m wondering how plausible that is to use a 2 MOA red dot at 200 or 300 yards, coveting 4” or 6” of the target, respectively to make small enough groups to refine a zero at distance. Now that I’m learning more of shooting, I’m calling bullshit here but open to the possibility it’s a legit thing.


Are some people doing custom zeros? Like an 87 yard zero or something fancy, where for their intended purpose, they get a flatter trajectory within that narrower set of distances? Any thoughts on these kinds of non-standard zeros?


Are people DOPE-into their red dot carbines, or are they plugging barrel length and round into a calculator program to find trajectory? I assume people don’t bother with actual DOPEs since the application of a red dot carbine doesn’t make much sense for for that. Do you really need to know the holdover is 3.5 inches at 185 yards? Or do you just put the dot on the target out to 200 and call it good enough? And the. Possibly memorize the holdovers for 300, 400, 500, 600 for 5.56 out of your gun, in the event of some crazy shot you need to make with nonmagnified red dot? Which holdovers outside of zeroing range (200 or 300) do you find useful to know?


Do you zero for “duty” loads like 62 gr soft point or 75 grain TAP, and then shoot cheaper 55gr FMJ to learn offsets with that cheaper practice round? And then if taking a class, you apply those offsets as needed for longer shots?


Is it possible to zero the gun for duty ammo, then shoot cheaper 55gr FMJ, identify the exact zeroing adjustments, say it’s 5 clicks down and 2 clicks right. Then for a training class, dial those adjustments into the aimpoint. And when done, dial the same ones backwards, and would that return you to the zero for the duty rounds? I assume this should technically work, although I also assume that most classes for carbines are 90% out to 50 yards or less, and 10% of the class might be 100 yards, due to logistics of open enrollment classes lacking access to longer ranges and open enrollment student base not interested in 200 yard carbine shots.

My point being, I’d bet it would work to temporarily adjust the aimpoint zero with a note on how to revert it without shooting any duty ammo, however the offset is likely irreverent to the average open enrollment class. Although, the effort seems fairly low, if it technically works. Show up to the class with the gun zero for duty ammo. During the zero portion of class, shoot the cheaper ammo. Take good notes on how many clicks you made. And then revert later at end of class.


With ammo availability being touchy, I wonder if I can identify the five different commonly available 5.56 cheaper 55gr loads I buy. Like I used to get magtech but that dried up and now it’s X-tac. And I wonder if I can take the effort to record the zero differences compared to the baseline duty loadout. So the gun stays zeroed for the duty ammo. And if I can find magtech then I look in my notes where 3 years ago I had identified the zero difference is 7 clicks down and 2 clicks left relative to the duty ammo zero. And then not even need to take the effort to zero it, just dial those clicks I previously identified. Or maybe the different lots of non-match grade ammo are so different over time, it won’t hold true?


As I’m getting more into carbines, I realize there’s the potential for some interesting ideas beyond the basics of zeroing.

Do any of these ideas have merit? What advanced zero techniques do you use?

If the goal is a 200 yd zero, you absolutely need to do it at 200. A “multipLe distance zero” or whatever you want to call it is a very general rule of thumb depending on a lot of variables like velocity. Don’t think that just because you zero’d at 50m, it means you’ll be POA/POI at 200m. As far as dots at distance, you absolutely can, but it is difficult depending on target size unless you’re talking accuracy by volume. If I expect that more than 1/4 of my targets are at 200+, I’m taking a 14.5 with magnification.

No point to a rando zero. 50 or 100 covers every base I have.

Most of my shooting has always been 100 or under. However if not for the ammo craze, I was getting into longer range shooting and planned on throwing a card on my buttstock with holds since I don’t do mental numbers well. Again, if you’re talking about precision, it absolutely needs to be the same round.

I zero everything with the round it was built to fire - typically my HD round of 75gr GD or something like MK262 for the distance guns. However, I’ve found that 75gr AE is pretty close to GD so I’ll actually zero with that and then confirm with a five round group of GD. I’ve never worried about zeros for classes. I’ve taken a bunch and very rarely have we shot past 100 or even 50. I’ll shoot whatever is cheapest for that and not bother rezeroing.

Theoretically, you can run multiple zeros by taking notes and readjusting based on the round. There will be some variation lot to lot but if you’re not detailed enough to be rolling you’re own and especially if you’re shooting a dot, you probably won’t notice. It’s easier to do it with an LPVO with zero stops and numbered turrets, but still possible. However, a good rule of thumb would be to always confirm with the duty ammo after making adjustments.


Sent from my iPhone using Tapatalk

[Wake27]

One thing I forgot to mention on the multiple zeros - the quality of the optic definitely matters. All clicks should be created equal, but may not necessarily. Turret tracking and other stuff comes into play here.


Sent from my iPhone using Tapatalk

[Sanch]

One thing I forgot to mention on the multiple zeros - the quality of the optic definitely matters. All clicks should be created equal, but may not necessarily. Turret tracking and other stuff comes into play here.


Sent from my iPhone using Tapatalk

I haven't heard of "turret tracking" before but I'm running Aimpoint Micro T1s and T2s.

[Wake27]

I haven't heard of "turret tracking" before but I'm running Aimpoint Micro T1s and T2s.

More of an magnified optic thing but may be a concern for RDS as well. Above anything else though, I'd probably be concerned about parallax with the T1s.

[TWR]

So thinking about different ammo and I’ve always been able to get by with M193 as a cheap substitute for practice, I decided to see just how close everything is.

Started off with my 16” Sionics pencil barreled gun with the Trijicon Accupower 1-4 with the segmented circle reticle. It’s zeroed for my hunting reloads consisting of a Nosler 55 grain ballistic tip at 3100 FPS with TAC. I put the dot on top of the top white label and fired 5 shots. Not really shooting for groups just shooting as soon as the dot came back on target. This was at 200 yards and I aimed high because it is zeroed at 100 yards.

Then I shot IMI M193 at the second label in the center not thinking about the 100 yard zero.

The third was my 77 grain MK262 clone again center of the label.

The fourth was my 62 grain MK 318 clone, I knew I pulled the low shot.

The only load that was really off is the MK 262 about 2” right. I thought maybe I had my head not centered or who knows what so I shot another 5 shots on a different target with the same results.


Everything was about 1.5 moa and that’s all I expect from this gun and my shooting. Not bad for a chrome lined pencil barrel at 200 yards with a 1-4 scope.