50 yard zero

[Chace grubb]

Would you consider this a decent 50 yard zero? Shooting from prone with a backpack supporting the gun.

AR-15
Sig Romeo 5 red dot
12.5 Rosco barrel
Rise armament RAV140 trigger
Surefire Warcomp
62grain 5.56 Fortis Scott ammo

 

[ELCO82]

Absolutely not.

 

[GIXXER2000]

No the only thing I zero at 50 is my 22lr

 

[hlee]

The only question that matters is “does this zero allow you to use the rifle the way you need to use the rifle?”

 

[strikeeagle1]

What Hlee said!
I have this 4.5" and here are some 30 yard targets. Good enough for its intention.

 

[Rerun7]

Not good at all. Both from the size of the group and the POI.

 

[Rerun7]

What Hlee said!
I have this 4.5" and here are some 30 yard targets. Good enough for its intention. View attachment 8144843View attachment 8144844View attachment 8144845View attachment 8144846

It’s stuff like this that makes me think maybe the dems are right and people should have to take an exam before owning guns…

 

[Makinchips208]

Would you consider this a decent 50 yard zero? Shooting from prone with a backpack supporting the gun.

AR-15
Sig Romeo 5 red dot
12.5 Rosco barrel
Rise armament RAV140 trigger
Surefire Warcomp
62grain 5.56 Fortis Scott ammo


View attachment 8144325

Just remember to CENTER THE GROUP. It appears the center of the group is off, maybe you pulled the two low right?
If you like the 50 yard zero and personally are happy with the group size, then center the group and you are done.

 

[OREGUN]

Nice first post.
Why shoot it prone? Not exactly a precision setup. Stand up and blast a home intruder size target. Are you staying in the center of mass? Good enough.

Objectively, your zero is off and your group kinda sucks.

 

[strikeeagle1]

It’s stuff like this that makes me think maybe the dems are right and people should have to take an exam before owning guns…

Post-up your 4.5" 5.56 targets...standing by.

 

[OREGUN]

Post-up your 4.5" 5.56 targets...standing by.

I thought he was referring to the gawd aweful looking collection of parts lashed to a hog saddle. But maybe the targets too.

 

[ELCO82]

What Hlee said!
I have this 4.5" and here are some 30 yard targets. Good enough for its intention. View attachment 8144843View attachment 8144844View attachment 8144845View attachment 8144846

 

[hlee]

If I have learned anything from my extensive time at YouTube university, it is that “the mission drives the gear.” The OP hasn’t defined the mission, but I think we can make a few inferences from the gear.

Let’s start with the postulate that a “rack grade” m4 shooting m855 ammunition would be hard pressed to shoot an equivalent group. Could it be done? Yes. But the internet says that is a 3-4 moa combo.

Is this a PRS/NRL/ELR (any flavor of precision) rifle? No.

3gun rifle? Honestly, I don’t know much about 3gun, but what I have seen suggests that shooters like longer barrels for this (16”-18”). Let’s call it a NO for 3gun.

Hunting rifle? Most hunters like a magnified optic for hunting, so probably not, but we can’t totally discount a “hog gun.”

Truck gun? Possibly, but I generally equate a truck gun to a generalist hunting rifle, and would expect a magnified optic like a LPVO. I suppose it could be a “get home rifle,” but if your commute makes the use of a defensive carbine a reasonable likelihood, I’m questioning your living situation. And, I’m not leaving a NFA item lying around in a mobile glass box for extended periods.

Run and gun? I’ve seen a number of competitors using guns like this. Mark it a maybe. The targets are generous and relatively close. Like full sized ipsc targets at 300y and in. A 2 moa group is more than sufficient for this. The orientation of that zero is unlikely to be the sole cause of a miss here.

Home defense rifle? This looks like a HD gun to me. Most shooters would be hard pressed to shoot an equivalent group with their HD pistol at 1/2 the distance, but consider it quite adequate to the task. If a softball sized group at 10 yards is sufficient for a HD pistol, a $0.50 piece sized group is sufficient for a HD rifle.

Is it a “good group?” Meh.

Is it “good enough?” Yes.

 

[Rerun7]

Post-up your 4.5" 5.56 targets...standing by.

I wasn’t even talking about your scattergun looking groups

That’s a real redneck meth-head looking build you got going there.

 

[OREGUN]

Is this actually a “my barrel is shorter than your barrel” thread?

 

[shoobe01]

Edit: I confused the OP with a response...

• Why do you have such a short gun, with a folding stock? If there is a reason, tell us what it is so we can advise.
• The rear sight needs to go ALL the way to the back.
• The front sight needs to be more forward. If it has to be back this far, and generally for expected ranges and the reliability of most RDS, I'd dump both of the irons instead.
• Can you activate the light switches? If not, consider putting it underneath.
• I find it hard to believe that the buttstock is at optimal length for your body all the way in.
• Again need mission, but it's unlikely it's a good idea to have the spare mag on the gun. Bulky, and the gun is already too tail heavy to shoot well without it.
• I'd think about a VFG. With barrels this short, handguard grabbing can be hard. I mean it: think about it. Make sure you are comfortable shooting this, and if not then fix the problem.
• Another option is a longer handguard. Most often with suppressors, but I have seen people add a couple inches to guns like this when they go with linear-comps or blast cans, so no gas comes sideways at the handguards. The hand stop gets more important though!
• Your zero is off. Or you are pulling all shots, but you should be able to hit the center of the plate,
• Your groups are too big. Offhand at 50 with a stocked firearm you should be striving for under 3" circles. On a tripod, if not under 2" something is wrong.
• I'd zero at 100 or MPBR (look it up, find a calculator). Not 50. No matter how short, it is a dotted stocked rifle-caliber firearm. You should be able to engage things to say... 200 yds.
• 50 yd zero will get your trajectory rising above the POA ... and falling below it at other ranges. MUCH harder to remember all this under stress.
• 100 yd zero will rise to the 100 yd range, and be only 1/2" low at 50 yds. Your MV influences drop a lot at distance but you are looking maybe...6" low at 200 so worst case if you forget to hold high then you still most likely hit.
• With your barrel length, after about 200 yds your velocity even with the best bullets for this start to just poke .22 cal holes in the target, and may fail to penetrate intermediate barriers. Maybe shorter than that depending on the MV you are getting.

 

[msgriff]

• Why do you have such a short gun, with a folding stock? If there is a reason, tell us what it is so we can advise.
• The rear sight needs to go ALL the way to the back.
• The front sight needs to be more forward. If it has to be back this far, and generally for expected ranges and the reliability of most RDS, I'd dump both of the irons instead.
• Can you activate the light switches? If not, consider putting it underneath.
• I find it hard to believe that the buttstock is at optimal length for your body all the way in.
• Again need mission, but it's unlikely it's a good idea to have the spare mag on the gun. Bulky, and the gun is already too tail heavy to shoot well without it.
• I'd think about a VFG. With barrels this short, handguard grabbing can be hard. I mean it: think about it. Make sure you are comfortable shooting this, and if not then fix the problem.
• Another option is a longer handguard. Most often with suppressors, but I have seen people add a couple inches to guns like this when they go with linear-comps or blast cans, so no gas comes sideways at the handguards. The hand stop gets more important though!
• Your zero is off. Or you are pulling all shots, but you should be able to hit the center of the plate,
• Your groups are too big. Offhand at 50 with a stocked firearm you should be striving for under 3" circles. On the tripod, if not under 2" something is wrong.
• I'd zero at 100 or MPBR (look it up, find a calculator). Not 50. No matter how short, it is a dotted stocked rifle-caliber firearm. You should be able to engage things to say... 200 yds.
• 50 yd zero will get your trajectory rising above the POA ... and falling below it at other ranges. MUCH harder to remember all this under stress.
• 100 yd zero will rise to the 100 yd range, and be only 1/2" low at 50 yds. Your MV influences drop a lot at distance but you are looking maybe...6" low at 200 so worst case if you forget to hold high then you still most likely hit.
• With your barrel length, after about 200 yds your velocity even with the best bullets for this start to just poke .22 cal holes in the target, and may fail to penetrate intermediate barriers. Maybe shorter than that depending on the MV you are getting.

Are you conflating the OP with post #5 (not the OP)? If you're addressing post #5, it would help if you quoted that post to cut down on confusion.

 

[TonyTheTiger]

• I'd zero at 100 or MPBR (look it up, find a calculator). Not 50. No matter how short, it is a dotted stocked rifle-caliber firearm. You should be able to engage things to say... 200 yds.
• 50 yd zero will get your trajectory rising above the POA ... and falling below it at other ranges. MUCH harder to remember all this under stress.
• 100 yd zero will rise to the 100 yd range, and be only 1/2" low at 50 yds. Your MV influences drop a lot at distance but you are looking maybe...6" low at 200 so worst case if you forget to hold high then you still most likely hit.

You're making the 50 yard zero thing more complicated than it is. If you can remember .5" low at 50 and 6" low at 200 for a 100 yard zero and eyeball enough Kentucky elevation to make a hit on vitals at those ranges, then clearly you can see how that same logic can be applied to a 50 yard zero and realize that a 2" hold under from 90-170 yards and a 2" holdover out to 250 is basically a dead hold from 40-240 yards on anything bigger than a squirrel.

 

[redbullitt]

I kinda like the 50 yard zero for red dot 5.56 . : / lol

 

[D1gger]

I actually went with a 60yd zero on the rifle I use for team matches (18" 556, 77gr SMKs). Based on my ballistic data, its about a dead hold to 200 and it lines up my 300yd with 2mils, 400 with 3mils and 500 with 4mils, or within .1 or .2-good enough for hold over stages. If I know the exact distance and have time, I'll dial. So far so good

 

[houndog]

OP - Not sure why you'd settle for "good enough" when you can do better. Why not take the time to shoot of a solid rest and try to shrink and center those groups? No matter what kind of shooting you do after that, you've given yourself your best chance of hitting what you're shooting at.

As to what distance to zero you're rifle at - my somewhat simplistic rule is: 1) if it has a magnified optic on it 100 yard; 2) if it has a red dot on it 50 yards; 3) if it's a PCC 25 yards.

My rational is pretty simple. My scoped rifles generally have longer barrels and are set up for shooting at distance. That means primarily from the bench or from a semi-supported position - i.e. prone, sitting, etc. Yes, I have one rifle with a 1-6x scope that I sometimes shoot offhand at 50 yards and in, but not that hard to remember to hold a little high. My red dots are generally on rifles with barrels under 12". I shoot these almost exclusively offhand, predominately at 50 yards and in with some shooting out to 100. Because I have a pretty significant astigmatism, shooting these rifles out to 200 is pretty challenging. 50 yard zero seems like a decent compromise. My PCC is zeroed at 25 because I generally use this to shoot steel challenge and targets generally range from 7 yards to 35 yards - with most targets being 25 yards and in. Again seems like a pretty good compromise.

 

[mark5pt56]

OP, while it may seem "acceptable" to some, I would shoot at longer distances if possible to check impacts, my guess they will be to the left. Remember though that your dot intensity, lighting and even target type can affect things. Shoot 10 rounds and tweak if necessary.
Other than that, the 50 yard zero with a dot is very useful. With a dot, if you can see it, you can hit it, dudes aren't going to be wearing bright jumpsuits waving "shoot me!, shoot me!" And that doesn't change because one has a LPVO

 

[TonyTheTiger]

OP, while it may seem "acceptable" to some, I would shoot at longer distances if possible to check impacts, my guess they will be to the left.

You bring up a good point. What's close at 50 may be 3" high and left at 200. 50 is too close to really fine tune a zero if you are intending to use the rifle much further than 100 yards.
I've got quite a few rifles that have 45, 50, 60 yard zeroes, but those are just the initial sight in distances. What I really have, and verify at distance, are mostly 210, 220ish yard zeroes. This gets all my scopes with BDC's lined up very well out to 5-600 or so.

 

[Rerun7]

For my general purpose rifle I haven’t found anything better than a 200yd zero. Anything between 25yd-250yds is just a dead hold. I’m not shooting groups with it or dialing drops and I have the need to quickly transition across multiple target ranges quickly so it’s very fast. However, that’s from a 16” barrel. OP is shooting a 12.5” barrel so velocity is reduced.

OP, at 50 yards it’s reasonable that your groups should be about 1”-1.5” because standard XM193 bulk will group at around 2”-3” at 100 yards on average. If you’re reloading that should shrink considerably.

 

[Molon]

Why shoot it prone? Not exactly a precision setup. Stand up and blast a home intruder size target. Are you staying in the center of mass? Good enough.

Objectively, your zero is off and your group kinda sucks.

Because people who actually know what they're doing know that zeroing a semi-automatic AR-15 with a red dot sight from the prone supported position is a good way to quickly obtain a solid zero and many people are interested in doing more than just "blasting at a home intruder size target".
...

 

[Molon]

Post-up your 4.5" 5.56 targets...standing by.

Were your groups fired off-hand, or from that tripod that the AR-15 is strapped into in your picture? Either way, here's a quick 10-shot group fired off-hand at 25 yards using a AR-15 with a red dot sight.

....

 

[Molon]

Let’s start with the postulate that a “rack grade” m4 shooting m855 ammunition would be hard pressed to shoot an equivalent group.

The OP wasn't using M855. He was using match-grade Fort Scott ammunition. An AR-15 with a quality chrome-lined, NATO chambered barrel shooting match-grade ammunition from the prone supported postition using a red dot sight is capable of significantly better accuray/precision than what the OP obtained.

The 10-shot group pictured was fired from one of my Noveseke barreled AR-15s from the prone supported position using an Aimpoint sight using match-grade ammunition.

 

[hlee]

The OP wasn't using M855. He was using match-grade Fort Scott ammunition. An AR-15 with a quality chrome-lined, NATO chambered barrel shooting match-grade ammunition from the prone supported postition using a red dot sight is capable of significantly better accuray/precision than what the OP obtained.

The 10-shot group pictured was fired from one of my Noveseke barreled AR-15s from the prone supported position using an Aimpoint sight using match-grade ammunition.

My point is that a rack grade m4 with m855 is “good enough” for most applications where a shooter is employing a red dot equipped SBR. This gun is shooting as well or better than that. This is not a precision set up. It is more than sufficient for a home defense gun. Can it be better? Yes. Is that a requirement? Not necessarily.

 

[Molon]

I wasn’t even talking about your scattergun looking groups

My handguns can produce better groups than those.

...

 

[Molon]

My point is that a rack grade m4 with m855 is “good enough” for most applications where a shooter is employing a red dot equipped SBR. This gun is shooting as well or better than that. This is not a precision set up. It is more than sufficient for a home defense gun.

No one claimed that his set-up is a precision set-up and neither is my Noveske-barreled AR-15 that produced the group I posted above. Show us, exactly, where the OP claimed that he was only going to be using his set-up as a home defense gun.

.....

 

[carbonbased]

What Hlee said!
I have this 4.5" and here are some 30 yard targets. Good enough for its intention. View attachment 8144843View attachment 8144844View attachment 8144845View attachment 8144846

That thing must be whisper quiet.

 

[Rerun7]

That thing must be whisper quiet.

And virtually no flash or concussion.

Probably a real joy for the shooter and all those around him.

 

[carbonbased]

And virtually no flash or concussion.

Probably a real joy for the shooter and all those around him.

I think to improve his groups, he should add a brake. Tame that recoil.

 

[Molon]

• I'd zero at 100 or MPBR (look it up, find a calculator). Not 50. No matter how short, it is a dotted stocked rifle-caliber firearm. You should be able to engage things to say... 200 yds.
• 50 yd zero will get your trajectory rising above the POA ... and falling below it at other ranges. MUCH harder to remember all this under stress.
• 100 yd zero will rise to the 100 yd range, and be only 1/2" low at 50 yds. Your MV influences drop a lot at distance but you are looking maybe...6" low at 200 so worst case if you forget to hold high then you still most likely hit.

You seem to not understand the usage of a battle-sight zero. A 50 yard battle-sight zero is an extremely useful battle-sight zero for engagements out to ~250 yards. There is nothing to remember, no hold-overs, no hold-unders, when using a 5.56mm AR-15 with a red dot sight and a 50 yard battle-sight zero (beyond DQB distances) out to ~250 yards.

6" low at 250 yards is a MISS, all day and every day on an opponent that has half a brain in his head and knows to shoot from over cover or from a defilade position.

AR-15 Zeros and Trajectories

The 100 yard zero with a .223/5.56mm AR-15 carbine is a unique trajectory in that the bullet just “kisses” the line of sight at 100 yards and rides along it for approximately 10 yards before dropping back down below the line of sight. (Technically, the bullet does travel above the line of sight, but by only 0.010”; a fraction of the diameter of the bullet itself.)

For all other zeroing schemes, there are going to be two points were the bullet crosses the line of sight; the near-zero and the far-zero. For the near-zero, the bullet will cross the line of sight while traveling upward from the muzzle toward the apogee or “maximum ordinate,” its highest point of travel. For the far-zero, the bullet will cross the line of sight while traveling downward from the maximum ordinate.

Now, when assigning a name to a particular zeroing scheme, it would be helpful if that name gave descriptive information about that particular zero; that is, the name should give us information about the trajectory and how it is unique and differs from other trajectories.

As a point of reference, the Santose Improved Battlesight Zero is often referred to as a 50/200 yard zero, however this is incorrect. It is actually a 50 yard/200 meter zeroing scheme; and this is only with a very few particular combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore. As an example, a 20” barreled AR-15 A2 firing 62 grain M855 will not match the 50 yard/200 meter IBZ. Neither will a 16" barreled RECCE firing 77 grain MK262, nor a 14.5” barreled M4 carbine firing the 70 grain 5.56mm Optimized "Brown Tip" load. The same concept applies when people refer to a 50/225 yard zero. Only a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore will match that description.

What this is all leading up to is this; except for a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore, a 50 yard zero is a different zero than a 200 yard zero. For a 200 yard zero, we know that this trajectory will produce a far-zero in which the bullet will cross the line of sight at 200 yards in its downward travel from the maximum ordinate. (It is physically impossible to produce a 200 yard near-zero with any of the commonly available loads and barrels lengths used in .223/5.56mm AR-15s.) Other than for a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore, the near-zero of the 200 yard zero will not be at 50 yards.

Conversely, a 50 yard zero tells us that this trajectory will have a near-zero in which the bullet crosses the line of sight at a distance of 50 yards in its upward travel to the maximum ordinate. For those who think that a zeroing scheme must be named after its far-zero, it is physically impossible to produce a far-zero of 50 yards with any of the commonly used loads and barrel lengths in .223/5.56mm AR-15s. The 50 yard zero can only be the near-zero.

Here are a couple of illustrations to aid in understanding some of the concepts described above. Lets start with the 100 yard zero as a reference point. As described above, with a 100 yard zero, the bullet’s trajectory just “kisses” the line of sight at 100 yards. Now, let’s increase the elevation setting of the sights/scope. As this is done, the near-zero can only move closer and closer to the muzzle. Concomitantly, the far-zero moves farther and farther away from the muzzle.

For the next illustration, we’ll start with the 100 yard zero again, only this time let’s decrease the elevation setting of the sights/scope. As this is done, the bullet’s trajectory can only fall away from the line of sight. The bullet will never cross the line of sight again; no zero at all.

Other than for a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore, the far-zero of the 50 yard zero will not be at 200 yards; and for all practical purposes it matters not one bit. Whether the bullet crosses the line of sight for the second time (far-zero) at 189 yards, 200 yards, 215 yards or 225 yards will not make the slightest bit of difference in the practical application of the AR-15 as a defensive weapon. In each case we will be holding the same POA (beyond CQB distances) and know that we will be hitting within approximately 2 inches above or below that POA out to 200 yards (or farther depending upon barrel length and load.) You should have an idea what your actual far-zero is when using a 50 yard zero and confirm such at distance when possible, but again it’s most likely not going to be a 200 yard far-zero and again it does not need to be.

Choose your zeroing scheme based on the pertinent facts; not nonsense about “shooting through a cone.” When shooting at human targets, in the grand scheme of things there isn’t going to be any practical difference between a point of impact that has a negative deviation from the point of aim, (e.g. the bullet strikes 1.5” below the point of aim) and a point of impact that has an equal positive deviation from the point of aim (e.g. the bullet strikes 1.5” above the point of aim.) In other words, the absolute value of the point of impact from the point of aim (how far the point of impact deviates from the point of aim, regardless of whether it is a positive or negative deviation) is what we need to be concerned about. Therefore, one of the main points to consider when choosing a battle-sight-zero is this: What zeroing scheme produces the smallest absolute values for the deviations of the points of impact from the point of aim, over the distance that we reasonably expect to engage a human target in our intended usage?

The chart below illustrates the above concept. The chart compares the absolute values of the deviations of the points of impact from the point of aim (0.0 inches on the graph being the point of aim/line of sight) for a 50-yard-zero and a 100-yard-zero, using Hornady 5.56 TAP T2 ammunition.

As you can see in the graph above, from the muzzle (0 yards) to approximately 62 yards, the 50-yard-zero has a slight advantage over the 100-yard-zero. Between the distances of 62 yards and 165 yards, the 100-yard-zero has the advantage. From the distance of 165 yards out to the 250 yards shown in the graph, the 50-yard-zero has a distinct advantage over the 100-yard-zero. Choose your zeroing scheme based on the pertinent facts.


.....

 

[Molon]

I actually went with a 60yd zero on the rifle I use for team matches (18" 556, 77gr SMKs). Based on my ballistic data, its about a dead hold to 200 and it lines up my 300yd with 2mils, 400 with 3mils and 500 with 4mils, or within .1 or .2-good enough for hold over stages.

The OP is using a red dot sight, not a scope with a reticle.

...

 

[OREGUN]

You seem to not understand the usage of a battle-sight zero. A 50 yard battle-sight zero is an extremely useful battle-sight zero for engagements out to ~250 yards. There is nothing to remember, no hold-overs, no hold-unders, when using a 5.56mm AR-15 with a red dot sight and a 50 yard battle-sight zero (beyond DQB distances) out to ~250 yards.

6" low at 250 yards is a MISS, all day and every day on an opponent that has half a brain in his head and knows to shoot from over cover or from a defilade position.

AR-15 Zeros and Trajectories

The 100 yard zero with a .223/5.56mm AR-15 carbine is a unique trajectory in that the bullet just “kisses” the line of sight at 100 yards and rides along it for approximately 10 yards before dropping back down below the line of sight. (Technically, the bullet does travel above the line of sight, but by only 0.010”; a fraction of the diameter of the bullet itself.)

For all other zeroing schemes, there are going to be two points were the bullet crosses the line of sight; the near-zero and the far-zero. For the near-zero, the bullet will cross the line of sight while traveling upward from the muzzle toward the apogee or “maximum ordinate,” its highest point of travel. For the far-zero, the bullet will cross the line of sight while traveling downward from the maximum ordinate.

Now, when assigning a name to a particular zeroing scheme, it would be helpful if that name gave descriptive information about that particular zero; that is, the name should give us information about the trajectory and how it is unique and differs from other trajectories.

As a point of reference, the Santose Improved Battlesight Zero is often referred to as a 50/200 yard zero, however this is incorrect. It is actually a 50 yard/200 meter zeroing scheme; and this is only with a very few particular combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore. As an example, a 20” barreled AR-15 A2 firing 62 grain M855 will not match the 50 yard/200 meter IBZ. Neither will a 16" barreled RECCE firing 77 grain MK262, nor a 14.5” barreled M4 carbine firing the 70 grain 5.56mm Optimized "Brown Tip" load. The same concept applies when people refer to a 50/225 yard zero. Only a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore will match that description.

What this is all leading up to is this; except for a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore, a 50 yard zero is a different zero than a 200 yard zero. For a 200 yard zero, we know that this trajectory will produce a far-zero in which the bullet will cross the line of sight at 200 yards in its downward travel from the maximum ordinate. (It is physically impossible to produce a 200 yard near-zero with any of the commonly available loads and barrels lengths used in .223/5.56mm AR-15s.) Other than for a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore, the near-zero of the 200 yard zero will not be at 50 yards.

Conversely, a 50 yard zero tells us that this trajectory will have a near-zero in which the bullet crosses the line of sight at a distance of 50 yards in its upward travel to the maximum ordinate. For those who think that a zeroing scheme must be named after its far-zero, it is physically impossible to produce a far-zero of 50 yards with any of the commonly used loads and barrel lengths in .223/5.56mm AR-15s. The 50 yard zero can only be the near-zero.

Here are a couple of illustrations to aid in understanding some of the concepts described above. Lets start with the 100 yard zero as a reference point. As described above, with a 100 yard zero, the bullet’s trajectory just “kisses” the line of sight at 100 yards. Now, let’s increase the elevation setting of the sights/scope. As this is done, the near-zero can only move closer and closer to the muzzle. Concomitantly, the far-zero moves farther and farther away from the muzzle.

For the next illustration, we’ll start with the 100 yard zero again, only this time let’s decrease the elevation setting of the sights/scope. As this is done, the bullet’s trajectory can only fall away from the line of sight. The bullet will never cross the line of sight again; no zero at all.

Other than for a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore, the far-zero of the 50 yard zero will not be at 200 yards; and for all practical purposes it matters not one bit. Whether the bullet crosses the line of sight for the second time (far-zero) at 189 yards, 200 yards, 215 yards or 225 yards will not make the slightest bit of difference in the practical application of the AR-15 as a defensive weapon. In each case we will be holding the same POA (beyond CQB distances) and know that we will be hitting within approximately 2 inches above or below that POA out to 200 yards (or farther depending upon barrel length and load.) You should have an idea what your actual far-zero is when using a 50 yard zero and confirm such at distance when possible, but again it’s most likely not going to be a 200 yard far-zero and again it does not need to be.

Choose your zeroing scheme based on the pertinent facts; not nonsense about “shooting through a cone.” When shooting at human targets, in the grand scheme of things there isn’t going to be any practical difference between a point of impact that has a negative deviation from the point of aim, (e.g. the bullet strikes 1.5” below the point of aim) and a point of impact that has an equal positive deviation from the point of aim (e.g. the bullet strikes 1.5” above the point of aim.) In other words, the absolute value of the point of impact from the point of aim (how far the point of impact deviates from the point of aim, regardless of whether it is a positive or negative deviation) is what we need to be concerned about. Therefore, one of the main points to consider when choosing a battle-sight-zero is this: What zeroing scheme produces the smallest absolute values for the deviations of the points of impact from the point of aim, over the distance that we reasonably expect to engage a human target in our intended usage?

The chart below illustrates the above concept. The chart compares the absolute values of the deviations of the points of impact from the point of aim (0.0 inches on the graph being the point of aim/line of sight) for a 50-yard-zero and a 100-yard-zero, using Hornady 5.56 TAP T2 ammunition.

As you can see in the graph above, from the muzzle (0 yards) to approximately 62 yards, the 50-yard-zero has a slight advantage over the 100-yard-zero. Between the distances of 62 yards and 165 yards, the 100-yard-zero has the advantage. From the distance of 165 yards out to the 250 yards shown in the graph, the 50-yard-zero has a distinct advantage over the 100-yard-zero. Choose your zeroing scheme based on the pertinent facts.


.....

Jeezus. Thank gawd someone is finally here who knows what they’re doing. . Did you go to the air farce academy?

 

[hlee]

No one claimed that his set-up is a precision set-up and neither is my Noveske-barreled AR-15 that produced the group I posted above. Show us, exactly, where the OP claimed that he was only going to be using his set-up as a home defense gun.

.....

He did not specify a usage. I inferred the usage from SBR, red dot, and “budget barrel.” Nothing on that gun says precision. Maybe the OP could come back and let us know what he intends the rifle for. But, good enough is- by definition- good enough. Perfection is the enemy of progress.

Then again, maybe the OP intends the rifle for short range bullseye competitions, or internet points, or overly verbose and repetitive pontification on accuracy and precision. If so, he has work to do.

 

[OREGUN]

Because people who actually know what they're doing know that zeroing a semi-automatic AR-15 with a red dot sight from the prone supported position is a good way to quickly obtain a solid zero and many people are interested in doing more than just "blasting at a home intruder size target".
...

You don’t need to say “semi-automatic AR-15”. That’s like saying 5:00 AM in the morning. Go back to call of duty, bro.

 

[Molon]

OP, at 50 yards it’s reasonable that your groups should be about 1”-1.5” because standard XM193 bulk will group at around 2”-3” at 100 yards on average.

The OP isn't using bulk ammunition. He's using expensive match-grade ammunition.

..

 

[OREGUN]

No one claimed that his set-up is a precision set-up and neither is my Noveske-barreled AR-15 that produced the group I posted above. Show us, exactly, where the OP claimed that he was only going to be using his set-up as a home defense gun.

.....

Thank Ulr yours is a Noveske barrel. Enough with the virtue signaling.


No one cares.

 

[Molon]

You don’t need to say “semi-automatic AR-15”. That’s like saying 5:00 AM in the morning. Go back to call of duty, bro.

Yeah retard, I do. Because if I don't, some piece of shit like you shows up and tries to contradict something that I've said based on the results of a straight-pull AR-15 or fully automatic AR-15 Go back to being a loser who contributes absolutely nothing of value.

..

 

[OREGUN]

Looser. You fucking idiot.

 

[Rerun7]

The OP isn't using bulk ammunition. He's using expensive match-grade ammunition.

..

I know. Making the point that even with bulk ammo it should group tighter than that.

Thanks for noticing though

OP also did not ask if he should use a 50yd zero but we’ve managed to beat that to death.

 

[mark5pt56]

You bring up a good point. What's close at 50 may be 3" high and left at 200. 50 is too close to really fine tune a zero if you are intending to use the rifle much further than 100 yards.
I've got quite a few rifles that have 45, 50, 60 yard zeroes, but those are just the initial sight in distances. What I really have, and verify at distance, are mostly 210, 220ish yard zeroes. This gets all my scopes with BDC's lined up very well out to 5-600 or so.

Yup, Some are shocked when they zero at 50, which is fine and then shoot out at 100, 200 and even 300. Again, what appears to be good, usually isn't.

 

[TonyTheTiger]

Looser. You fucking idiot.

 

[Desert_Racer]

My eyes cannot unsee what I have seen in this thread.

 

[OREGUN]

View attachment 8145526

Our retarded friend went back and edited his post! What a peach.

I should have quoted him.
Or gone with a “looser” joke about his mom.

 

[Makinchips208]

We need to bring back the 7 yard zero.
That’s what I do with my 15.5” semi auto loading gas gun ar15

 

[carbonbased]

Assuming one attaches a manly brake…

Who cares about one’s zero with a 4.5” AR15 shooting 556 with a humongous brake inside a structure at night?

The concussive sound alone of such a setup will IED-jelly an intruder’s brain.

After you groggily awake and realize that yes, you have bested this savage at his own game, half your face will lazily curl into a smile as you stare up at the ceiling.

What is this smile?

The smile of a champion.

The other half of your face will work soon enough.

 

[houndog]

So much going on in this thread. Still trying to understand post #5 by Strikeeagle. Is that really his gun? Did he intentionally set it up this way, and if so does he feel like some Seal Team 6 operator when he shoots it?

How about those groups? Are they something he's proud of? Are they at least offhand or did he really shoot them from that tripod? Is this whole post just a giant goof? I have so many questions.

I don't want to be mean spirited or pick on anyone, and if that gun works for you - that's great. At the end of the day most of us our just enthusiastic amateurs. I'm 65 with a bad back and a wonky heart, so it's not like I'm fast roping out of helicopters. But I've never seen anyone put together top tier parts in a way that makes less sense ... and with crappier results.