36yd zero?!?

[JPitts0117]

If this has been discussed feel free to remove, although I did search for it and found nothing I may not have used the correct search words. I was flipping through YouTube the other day watching some videos, and came across one from a training company known as Vigilance Elite called,” A Spec Ops Dudes favorite combat rifle zero”. In the video “ex-navy seal” Shawn Ryan, talks about the normal zeros...25,50,100, but he also speaks of an unusual one of 36 yards. He goes over bullet drop for each specific zero, and overall the 36yd zero has the closest gaps from 0-300. Granted no bullet weight value was given so I’m guessing he was using xm193. Has anyone used this 36yd zero? If so was it nearly as close of a group as he suggested in the video?

 

[JPitts0117]

 

[ggammell]

What exactly do you intend to shoot? And in what terrain?

 

[Matt Landfair]

is combat zero like combat accuracy?

 

[JPitts0117]

Thatd be my guess Matt. The rifle I’m mainly asking about will my 6920, a backup to my issues duty rifle,and a training rifle in all sorts of terrain. Mostly flat range stuff, but pretty much whatever the need calls for.

 

[Matt Landfair]

So many factors - what am I using it for? what caliber? what gun (barrel stats)? what ammo? what terrain?

We had a great discussion where the novice sees only black and white, yet the experienced knows the grey and exceptions.

 

[JPitts0117]

My personal gun would be a 6920 5.56 1/7 twist 16” basically new barrel less than 200rds in this particular gun federal equivalent of xm193 for ammo. Terrain would be mainly flat but situational dependent, also used for training. I know that there’s obviously tons of variables as with anything, I was just wondering about the viability of this zero system vs standard zero yardages.

 

[Matt Landfair]

dependent on the trajectory using all the factors.

 

[iFeelBad]

I have not used a 36 yard zero, but I did find this chart most of us have probably seen from Molon on some other forums.



While not the same as 55gr out of a 16in barrel, this might help.

 

[JLL2013]

There are some issues with a 36yd zero, much like a 25yd zero, and 10yd...something...are that you aren't getting enough data at that distance to true the weapon. You'll zero at that distance then shoot at 100, 200, and further and realize you're left/right because there's going to be an imperceptably small deviation that you can't see when zeroing that close.
The other issue is that all of these close range (25, 36, 50) zeroes are really the shortcut for something else whether its 25/350yd, 50/200yd, or 36/300yd. They're fine to get a starting point. But all the data and benefits as far as elevation deviation is really only present if you have a true 200 or 300yd zero.

 

[krax]

I couldn't make it through more than the first 20 seconds of that video. I'd avoid that channel, honestly. Once you added certain things to your social media profiles, you instantly become either a fraud and/or OPSEC-violating POS.

I've got nothing against a 25, 36, or 50yd zero if you don't have a longer range or plan to confirm at longer distances soon after you zero at the shorter distance. Doing something like a 7-50yd zero initially saves some time and ammo when mounting or moving an optic. The math we use at those distances is pretty generic though and rarely takes into account ammo, barrel length or atmospheric variables. You've got to know what your rifle does at rifle distances to progress past neophyte, and by "know" I don't mean what the chart on ATRAG, AB, or Strelok says.

I like either a 100 or 200yd zero for red dots. If you've got 200 yards/meters available, then use that. Ideally, find a range that'll allow you to zero at 100-200 and then get data at 7, 10, 25, 50, 100, 200, 300, and beyond if possible. You may get some weird looks at your local 1000yd range when you show up with a red dot, but that's because people trying to do it "right" are the weirdos these days.

 

[Sunshine_Shooter]

I have not used a 36 yard zero, but I did find this chart most of us have probably seen from Molon on some other forums.

View attachment 2688

While not the same as 55gr out of a 16in barrel, this might help.

A max ordinate of about 5" above the dot at 175 yards doesn't seem useful. I get that there is a time and place for everything, but this zero's time and place must be very specific to make it useful.

 

[Low_Speed_Notper8or]

A max ordinate of about 5" above the dot at 175 yards doesn't seem useful. I get that there is a time and place for everything, but this zero's time and place must be very specific to make it useful.

Yeah seems like something that might be useful in a military context where you are shooting at Hadj at extended ranges and want that long max point blank.

Though for me shooting things like 2 gun, being 5 inches high at 175 means with the inherent accuracy of my ammo and my marksmanship stacking into missing over the top of a mini-ipsc at 175. Shooting 55 grain stuff out of a 16 inch barrel I like the 50 yard zero because its basically point and click out to 225-50ish.

Heres a interesting chart I found

 

[Yondering]

A max ordinate of about 5" above the dot at 175 yards doesn't seem useful. I get that there is a time and place for everything, but this zero's time and place must be very specific to make it useful.

Instead of being very specific, it's actually used for a very general application in military use, so that soldiers can aim dead on to a torso out to 300 yards. This is done partly so they don't have to think about drops and hold-over.

Some guys like to use it, but IMO a reasonably proficient rifleman can do better with a 100 yard zero and learning his dope for extended ranges.

 

[Sunshine_Shooter]

Yeah seems like something that might be useful in a military context where you are shooting at Hadj at extended ranges and want that long max point blank.

Though for me shooting things like 2 gun, being 5 inches high at 175 means with the inherent accuracy of my ammo and my marksmanship stacking into missing over the top of a mini-ipsc at 175. Shooting 55 grain stuff out of a 16 inch barrel I like the 50 yard zero because its basically point and click out to 225-50ish.

Is hitting 5" above zero still considered point blank range? I personally run a 50yd zero on my rifle, max ordinate being approx 1.5" above zero. I've yet to have a need to shoot it beyond 60-70 yards, so I can't actually say what it does very far out.

@Yondering I guess hitting 5" above the center of a dude's chest is still in his neck, so that would be an effective hit. It just sounded like a lot when I first saw it.

 

[ArmedNovelist]

So, here's the other thing. I've always read the 36-300 zero to be a USMC doping procedure for their ACOGs (RCOs, as they are referred to), but it may be more broad or more simple than that explanation. It's referred to as a "field expedient zero" in the USMC Rifle Zeroing handbook. And, I am assuming, that it is predominately for an M4 with a 14.5-inch barrel length using whatever their standard ammo is (thank you Low_Drag for digging up that photo).

I have tested this dope on a 16-inch platform, same reticle type as the RCO, from 36- to 100-yards (range restricted) and the shot placements don't look all that different from the charts at that short range; but, you'd probably get more variation in elevation beyond 100-yards. About the only reason, and I have look at doing it seriously, for a 36-yard zero is to get more range out of the dope for a situation where I knew I wouldn't be able to fiddle with the turrets at all. The 400-yard hits, according to the chart that Low_Drag provided, show shots just above to dead on the pelvic girdle. This assuming you don't hold over slightly and just go for the chest.

I see merit to it, but with BDC reticles, there's merit in 100-yard doping after you learn the reticle.

 

[Low_Speed_Notper8or]

Is hitting 5" above zero still considered point blank range? I personally run a 50yd zero on my rifle, max ordinate being approx 1.5" above zero. I've yet to have a need to shoot it beyond 60-70 yards, so I can't actually say what it does very far out.

@Yondering I guess hitting 5" above the center of a dude's chest is still in his neck, so that would be an effective hit. It just sounded like a lot when I first saw it.

Depends on your target

Max point blank range depends on how large your target is. There is actually a ballistics calculator that will calculate your maximum point blank range depending on the size of your target.

If I could find it I will link it.

Also good stuff on your blog, I read some of it and really enjoyed it

 

[Low_Speed_Notper8or]

Point blank range caculator

http://www.shooterscalculator.com/point-blank-range.php?df=G1&bc=0.105&vi=1070&sh=1.5&ts=1.

I don't have access to it at work but I believe you can include MPBR on Shooters calculator when generating drop chart and table

 

[Ryan St.Jean]

Per the manufacturers manual ACOGs are to be zeroed at 100 meters.

 

[tact]

Per the manufacturers manual ACOGs are to be zeroed at 100 meters.

They are but the USMC first conducts the 36 yard zero and confirms at 100 to make final adjustments for the RCO.