The main purpose of my personal m4 is home defense, but I have also taken it, and likely will in the future, predator calling. It wears a Primary Arms Micro on it, and I really dig the sight. I had it sighted in at 100, but got to thinking that I will not likely shoot that far with the rifle in its main purpose. I then sighted it in at 50 and this seems like a much better set up.


Thoughts?

I think 50 is perfect for open sights or a red dot.
Only about 3" drop out to about 275 yards depending on your load.

I use a 50/200 meter zero on my scoped guns but like the 100 meter zero on my red dot sighted gun. Check out this thread.

http://www.m4carbine.net/showthread.php?107572-Zen-of-the-100-Meter-Zero

At HD distances (10 yards max in most homes) the sight height offset is going to be more of a factor than the range you're zeroed at. You're going to be holding 2ish" high regardless of where your zero is. No practical zero is going to compensate for that.

I'd zero for whatever range your predator hunting needs and then deal with the inevitable sight height offset.

From the M4C link

"Holding at the top of a 3" circle will place the round in the lower 1/3 of the circle at 3 yards, and in the upper 1/3 at 70 yards.
Holding in the upper 1/3 of the 3" circle (1 inch high) will place shots within the 3" circle from 30 yards to around 200 yards (though most shooter/weapon/ammo combinations will not be able to maintain that level of precision past 75 yards or so). "

Doesn't get any simpler.

That AR's gonna be LOUD indoors.

Reminds me of this.

Zero at 100 yards, it isn't going to make a difference worth mentioning in a HD situation. A center mass hit, is a center mass hit.

I have an EOTech on my HD AR, and a scope on the rifle I use for hunting. They do different things, and I want different sights on them.

50 yards dead on, its about 1.5 high at 100 with 55's. Just remember everything is low close up, you got to shoot the rifle at all distances and understand it.

This, plus the fact 2 inches won't matter at all ever in HD situations....and I doubt anyone would even remember to aim much at HD room defense situations.

Of course unless your rooms are in a multi million dollar house sized rooms. LOL

Ditto, I've got a 20" heavy barrel with a 3.5-10 Leupold that i 99.99% of the time I take predator calling. I enjoyed carrying the m4, ill likely do it again.

This.

Not only do I disagree with the above, but it is flat incorrect.

1). Guns, even 5.56mm, aren't death rays and still require proper shot placement. Lung shots, even with good 5.56, may or may not have the effect you need, even then HIGH center chest is where we should be to have an effect on the heart, spine, and/or great blood vessels- to say nothing of effective head shots. The heart is the size of a clinched fist.... 2 inches matters.



2). Any one that has been to a real training course and practices correctly at all- will use their sights if using an Aimpoint. No question. If they don't, they seriously need to reevaluate what they are doing.

Do you use absolute co-witness or 1/3 Cowitness

I prefer lower 1/3rd flip ups stowed in the down position.



That's necessarily what I would recommend others do.

50/200 for both BUIS and dot, lower 1/3rd cw mount, is my fav. KAC 50/200 200-600 micro flips track, and holdover for the dot when needed is my SOP.

The thing with the 50/200 is you have to hold over and under from zero to 200. The unique thing about zeroing at 100 is the bullet never rises above the line of sight.

Being a red dot is at its best up close to medium range all I have to remember is hold over, hold on and hold over. I would not use a red dot on a coyote past 150 yards so why sight in for a useable range of 300 that increases hold over and introduces hold under at 100?

this is from Travis Halley/AR-15.com, 50 on left, 100 in the middle, 300 on the right.

I use irons and I only see a blur in room distance targets. I have no problem making center hits. I"m not striving for all in the heart. I run the other way, I'd just as soon put as many bullets in as many vitals as I can.

YMMV, but sight height has never been an issue. Not even in IDPA matches, I still don't loose points due to sight height.

Jimmy, I can't explain Travis' results as they differed from mine. Properly sighted in at 100 yards, my 25, 50 and 75yard targets are low where Travis shows high for his 100 meter zero. I just haven't had this happen.

Also, no one is going to shoot that precise with a red dot to be able to zero at 300 meters with a red dot on a blank silhouette. Most red dot groups from 100 yards run 3" or so.

The 25/300 zero is nothing new and has had plenty of problems for years, don't know why it's supposed to work now.

I'd suggest shooting all 3 and see which works for you.

Of course its on the AR-15 website so it just must be true!!! I have no idea what ammunition he was supposedly using however I just use a 50 meter and will continue to do so as my brain is slow and old, but I can hit a baseball sized rock at 25 yards (dot goes on top) 50 (dot goes in center) 100 on a 3 inch red target (dot goes on bottom I cannot see a rock that good at 100) shooting off of a pine tree all without overthinking the situation nor having to learn Tactical speak.

The video/target from Travis is what happens when you use improper tests- how is he insuring that he is holdIMG in the exact spot for each shot? He's not.


We use a 100 yard/m zero across the board where I am. After lots and lots of testing, theory, and actual use- a 100 yard zero results in the most hits on realistic sized (8 inch and smaller) targets from contact to 200 yards and matches the 200m zero from 200-300 yards for hits on the same targets for a variety of reasons-


1) The bullet never crosses your line of sight- it's always on the dot or low.

2) You do not have a "200 yard" zero unless you make point of impact match point of aim AT 200 yards.

3) 100 yards is close enough that shot groupings are small enough to adequately find the center, yet far enough to show errors in zero the are masked at closer ranges. Farther than 100 yards and environmental factors start being a problem.

4) Red dots are truly 200m and in optics, and really 100-150m and in. The 100 yard or meter zero is iptimiz d for these ranges. Optics other than red dots are zeroed at 100 regardless. Continuity is good.

5) Offsets from side gun are significantly reduced with a 100 yard zero compared to all others.

6) Human tendency is to aim right on the target or high when under stress of any kind. Aiming under the face and into the wall that the person is hiding behind and shooting at you from is difficult for most people mentally and emotionally.










Intersting. How long do deer live when you "put as many bullets in as many vitals as you can"....?

And if they were a person how many rounds could/would they fire in that time...? And how may of those rounds could/would hit family, you, or innocents.....?

[video:youtube]ovYFkxdKJ8g[/video]

Another good read http://www.m4carbine.net/showthread.php?65679-AR-15-Zeros-and-Trajectories

Zero your gun regularly. Novel advice.

100 yd zero I don't know, let me try it this week

Never mind, this one was linked early on in the thread.

The net is good for ideas but you really need to shoot for yourself.

A lot of the folks who use the 50 yard/200 meter zero never know that their load does not match. I zero my scoped AR's at 200 yards because it fits my coyote hunting. I'm also just over an inch high at 100 yards after confirming for myself. This allows me to hold on fur out to 300 yards and I've had very few instances where shots were less than 50 yards, even fewer less than 20. If I set up for close shots, I carry a shotgun or a red dot equipped AR.

The red dot zeroed at 100 yards is set up for close range with the ability to reach out to 150-175.

Deer I would hope everyone would treat differently. I put an arrow in the deer and let em run off.....

You can do what you want, but Lord forbid I ever have to shoot someone, I"m going to put more than one round in them. I don't have family. I"m ok. Everyone in my house is in the same room. I"m still ok.

I live in the country. Any round I fire is going to have to go at least 400 yards before the chance of hitting someone else.
YMMV

Discussions of the US Armed Forces doctrine for a (BZ) Battlesight Zero vs. the later Lt. Colonel Santose’ doctrine for an (IBZ) Improved Battlesight Zero vs. the even later civilian (Revised) shorter range RIBZ, will often degrade into a debate much like an optics pissing match over who makes the best scope. What works for one, may not work for another.

To the OP, you can slice it up six ways to Sunday, bottom line, look at what you have, what you intend to shoot, and how far you need to shoot and still hit the darn thing. The below link has a pretty good visual target simulation, using an SBR, 14.5 Carbine, 16 Carbine, and 18 Rifle; shooting 193, 855, and 262 ammo. Good simple visual aid to compare POI with the differing combinations. Though USMC 318, and FED LE 62 training ammo is omitted, I’ve run both, in addition to those listed, and they all run pretty close to the same within those ranges. However, the 262, the 318, and even the 62 training ammo start to show their stuff, compared to the 193 around 400 yards or so, and of course, I think 855 is junk, so I pay it no mind. If you shoot an SBR, the 262 seems to upset well in terminal performance at the slower velocities when compared to the 193, so it is not just a good long range round.

It sounds like you have little interest in shooting beyond mid-range. I, however, would not let a micro, even a 4moa dot, and for that matter, even a good BUIS set, preclude me from shooting center mass on a man sized torso, or a predator the size of a ‘yote, well beyond 150 yards.

Good luck on whatever route you choose, but note, even if shooting 262s out of an SBR with intent for close quarters inside 50yds, a 50 yard/200 meter zero, ala IBZ, would work exceedingly well. And as for mid-range, on something the size of a yote up through a man sized torso, you’d stay under a couple inches of your point of aim, but in addition, you’d not drop out the bottom more than a couple inches until around 250 or so yards. Even with a 4moa dot, it is very easy to hit a man sized torso at 300 yards holding chest high, 400 yards holding top of head, and though I prefer a T2, even with the 4moa, a dot holdover above the head will drop the bullet into the chest at 500 yards. Very easy peasy, which is why so many follow the later IBZ doctrine to point blank max out the range of the 5.56 cartridge in that platform having a reduced high arc of the older BZ, while for the sake of this discussion, having a reduced and much more manageable holdover for the longer shots, in comparison to the RIBZ, for those who want to stretch the rifle out down range. Even for close quarter stuff with a much slower SBR, the bullet gets closer to your POA, faster, and stays closer to the aiming point out to 50 yards than an RIBZ. But in reality, at the distances you are talking about in this discussion, you’d not miss a yote because of either zero method, or because of having a 4moa dot.

Best, it is all fun, try them all for yourself!

http://arma-dynamics.com/zero-considerations.html

I like the 100 yard zero as well. The only thing I did not like about my SWFA 1-4 is the hashes are set up for a 200 yard zero. I am still getting the feel of it but am leaning towards a 100 yard zero and then just confirming the drops for the rest of the marks.

GaryVA, appreciate the link!

thank you for posting this, I am going to print it out and put it into my reference books.

For my purposes I do not see a distinct advantage for a red dot sighted gun for the 100 yard zero over the 50 yard zero.

Other than splitting hairs what am I missing?????

If you are shooting silhouettes at 25, 50 and 100, you're not missing anything. The 50/200 works just fine.

If you're shooting small targets like say a hostage target where the white target covers all but a 2" portion of the brown at 3 yards or at 82 yards, then your mind has to remember high or low?

Zeroing at 100 is just easier to remember under stress. Throw in a scope where longer ranges can be utilized and expected, then I'll take the 50/200. But in truth the 100 zero is still easier to deal with.

The hashes on the 1-4x SWFA Classic are mil based. All SWFA did was "tell" people that is a BDC, it's not. You can do the exact same thing with any mil reticle.


From center dot to first hash (maybe the gap) is .5 mil, after that it's in 1.0 mil increments.

there does not appear to be a "right" or "wrong" only what suits your anticipated needs and what you are more familiar with.

Like the man said "you pays your money and you takes your chances" on parachutes, life boats, life preservers, SD firearms and AR15 zeros.

I have sold my HK Squeeze Cocker, my AK47's, rarely carry a revolver anymore. Wheres the safety on this gun anyway, press that button to turn on the sight, I can hit a man sized target at 500 yards with my 5 MOA AK47 every time and did so the last time I shot it in 1996....

You having flashbacks on your WASR 10?

some of you guys buy guns like a rat on acid, you got to me more deliberate than that considering the zombies and all.

forgot to use the sarcasm font again.

TWR, I get it remembering everything is under the line of sight is easier. AL (all low)!

The last deer I killed ran past me at about 10 yards and yes I shot low into its shoulder, this scoped 6.8 was zeroed at 100 and sure it shot lower than I aimed so I had to shoot it again.

The nuances of the gun are often forgotten when the shooting starts. I have shot off a branch or 3 in my life and once shot a 1 inch diam tree down with a black powder gun but I killed that deer too.

Here is my question to the group. Given this discussion regards the AR always hitting low within inside the home ranges, should we be reconsidering single purpose shotguns?

2 inches low should be about all the low you see.

I don't know many that can consistently hit a 2 inch target in the heat of the moment anyway... chest cavity is big....

YMMV.

There's a reason lot's of 3 gun guys use off set sights for close shots.

Not saying this is right or wrong but I prefer to think of it as an angle from the bore to meet up with line of sight at 100 yards. It's easier in my simple mind to say at 50 yards it's half the drop instead of I'm on at 50 but at 30 I'm low and at 80 I'm high. The difference is only at most 2.7" but that can make a miss if you're counting X's or hearts.

If all things stood out in the open, it would make no difference but life is not always so easy.

rost said "I don't know many that can consistently hit a 2 inch target in the heat of the moment anyway... chest cavity is big...."

That's why we practice and use as many advantages as we can get. Running a red dot on silhouettes is where this can be easily seen. It is still there in hunting situations but I think we tend to chalk it up to the tenacity of the critters will to live rather than we just missed the vitals.

If you fail to kill an intruder because your sights are off 2-3 inches, its not the zero issue.

If we are talking hostage or head shot only, totally different and I"m expecting anyone doing this is going to know their zero exactly as its not so much a heat of the moment shot but a precision shot.

I know a guy who has been shot and survived in spite of the horrendous scars he has where the bullet actually deflected off bone and exited then re-entered his chest. The bullet bounced all around his chest and stomach missing his vitals. He didn't just lay down and wait to bleed out.

I couldn't care less how anyone else sights in but I hope folks will at least look at the info presented in the links and try it for themselves.

As for hostages and head shots, I've only tried it on cardboard while watching others do the same. It can be quite humbling when a shot slips into the white...

BTW, which red dot are you running on your HD AR?

for me nothing fancy just a T1 Micro with 2 MOA dot at 1/3 Co-witness using the DD "bolt it on with blue lock-tite" mount some steel flip ups forget whose they are now the gun is a DD M4V11 along with a Steamlight TLR-1 HL. Nothing high tech or cutting edge.

I put the T2 on my 6920 and mounted the tlr1 HL on the gas block. Using a Troy rear flip up.

mine is the TLR-1 HPL my mistake. It works outside well.

Thanks GaryVA.
That link confirms I'm very comfortable with my 50 yd. zero.

yes I as well

GaryVA.........thanks for the link.

Here's another one that's also pretty good, developed by Larry Vickers.

Zen of the 100 Meter Zero

MM

MM, did you alter the USMC backup sights on your KAC somehow to run a 100 meter zero?, or you just talking about running a 100 meter zero with the aimpoint, while running the 50/200 zero on your KAC BUIS??

My last training day, I ran a 300 round mix of ammo testing the KAC BUIS with the 50/200 zero. Ran drills from near point blank all the way out to 500, and it was the bomb. I prefer keeping the same 50/200 zero on the aimpoint mounted lower 1/3rd cw. But, there was at least one LMT SBR running the same drills using a 100 meter zero which did well, other than maybe some holdover issues at the longer ranges, but an SBR is not really designed to shoot that far anyway.

Best

My BUIS are set to 50/200 on both KAC's.

The 16" has a 1-4x SWFA scope with turrets zeroed at 100.

The 18" is intended generally for more longer range stuff & has a 3x10x NF with turrets zeroed at 200.

My bangers than have either low x scopes or red dots that are zeroed at 100 with BUIS zeroed at 50.

Different setups for different specifics but still lots of overlap & flexibility.

MM

Gary what kind of accuracy can you expect out of one of the 16 in KAC guns with a chromed barrel!? I got a DD M4V11 that shoot most anything into 2-4 MOA I am not overly happy with it it

What ammo are you shooting that gives you 2-4 MOA?

Mmost anything

Those that desire accuracy need to learn that its paid for in known names.... not DD or crap like that...

You go to a smith, get a Krieger, Rock, Obermeyer, Bartlein etc...

You only do it once and smile. Instead of buying and selling this and that and so on..

YMMV, but the results are likely to be very much the same in the end. Proven will work, the rest are just a guess.

The most accurate chrome lined barrels I have seen have been Colt. Even those will only throw ball ammo into 2+ MOA groups.

I know you might pay a lot for those chrome lined DD, KAC, etc high dollar barrels, but I've never seen them shoot worth a hoot. (<=3/4 MOA for 5 shots or even <= 1MOA for that matter).

Par for the course with these Mod2s seem to be around 1 moa. Shoots 193s surprisingly well, with stuff like the mk262s exceedingly well, at or under moa. Though it is a 5.56, the 16" doesn't seem finicky, shoots quality 223(FED LE 62) without issue so far. I've been shooting around moa +/- with the military and training ammo, not sure how tiny a group I could post from a bench with purpose built match ammo. This rifle is purpose built for battle, not x-count. But it is nice, however, having an ultra reliable battle rifle that also shoots very, very accurately.

http://ballisticradio.com/endurance-tests/kac-sr-15-mod-2/