As the title says I have access to a 25 yard range indoors where I can sight in my 14.5inch M4ergy. I usually use a 55gr FMJ round, typically the XM193 or Remingtons loading of a 55gr. Metal Case (MC) .223.

With that in mind I would like to sight both my Aimpoint and BUIS so that they hit exactly where I am aiming them at 50 yards. For what I have heard if I sight in my weapon at 50 yards I will be good to go out to about 300 yardd, is this correct?

How do I need to sight in my Aimpoint and BUIS at 25 yards in order to hit a target at 50 yards? Thanks!

I could be wrong here (since I always seem to get this backwards), but I believe you need to be about 2-3 inches low at 25, to be on at 50. Hope that helps  hug.gif

nevermind

Check around...it may be worth a little drive to find a nice range that goes out to 100. I'm sure theres one around ya somewhere. The sightin in procedure your talking about is what I believe they call the Improved Battlesight zero...I use this on my AR.
groups.msn.com/TheMarylandAR15ShootersSite/improvedbattlesightzero.msnw

The Maryland AR15 site linked above will have the exact info you need but IIRC impact at 25y should be approx 1 1/4 inch low to be on at 50y.

It would help if you had stated what type of rear sight you are using, and whether or not your aimpoint is cowitnessing the sights. If you have an A1, rotate it to the "L" aperture, and zero it. It will be a little off, as it is suppose to be zeroed at 25 meters (27.3 yds). Flip it back when you are done, and it will be zeroed for about 250 meters.

If you have an A2 rear sight, rotate the elevation wheel to "4", use the small aperture, and zero away. When you are done rotate the wheel to "8/3" -2 clicks for an A2, or "6/3" -4 clicks if it has a removeable charging handle. If you use the large combat sight just leave it at "8/3" or "6/3". It will get you close enough to be able to zero at 50 yds later. Of course, it goes without saying that you adjust the elevation with the front sight, leaving the elevation wheel on the "4" setting.

Then adjust your aimpoint, again assuming that you have it mounted so that it can cowitness, so that when you have a good nose to charging handle shooting position the red dot is split by the top of the front sight post. Remember that your zero should always be checked at 50 yds, and then rechecked at 200 meters (220 yds) if possible.

All this is explained on the Maryland AR-15 site under the zeroing section. You can find it here It is a good resource, and even has trajectory charts for the different zeroing methods, ammunition, and barrel lengths. It is well worth reading.

Stay in General Discussion if that's the level of contribution you are capable of. Thanks Aimless

Quoted: 25 yard range ! lol move out west man, our ranges have a distance limitation of how far can you see... and you want to have it sighted in for a longer distance ? why ? can you shoot anywhere that far ? stick to bb guns for your indoor range, and lemme guess you only get 15 minutes at lunch to play !! is this a serious thread ?? 25 yard range ?? flame me, trash me or whatever. but i am sitting here laughing ...25 yard indoor range...unbelieveable !!

You wasted a post to say that?

If you think this thread is funny ...A while back some guy posted asking the same question because he was having trouble sighting in his 3X ACOG at 25 yards!

LOL

Quoted: 25 yard range ! lol move out west man, our ranges have a distance limitation of how far can you see... and you want to have it sighted in for a longer distance ? why ? can you shoot anywhere that far ? stick to bb guns for your indoor range, and lemme guess you only get 15 minutes at lunch to play !! is this a serious thread ?? 25 yard range ?? flame me, trash me or whatever. but i am sitting here laughing ...25 yard indoor range...unbelieveable !!

Really helpful post there.

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Death_006, here's some data I generated for a 14.5" bbl, M193-spec Q3131A.  I used this calculator: http://www.eskimo.com/~jbm/calculations/traj/traj.html

You mileage may vary, but this should hold you over until you uproot your family, quit your job, leave your life behind and move to New Mexico to shoot at longer ranges like a he-man.   Or, maybe you're using this carbine for home/suburban/urban defense, in which case you're doing everything exactly right already.


Assumes: 3050fps muzzle velocity
55gr bullet
ballistic coefficient = .243
sight height = 2.6in.
Temp = 65 deg F
no wind

14.5" bbl with IBZ - CQB Trajectory
Q3131A (M193)


Range(yd) Impact(in) Velocity(fps)
0    -2.6    3050
5 -2.3 3019
10 -2 2999
15 -1.72 2979
20 -1.44 2959
25 -1.17 2939
30 -0.92 2919
35 -0.67 2899
40 -0.43 2879
45 -0.22 2860
50 0 2840
55 0.2 2821
60 0.39 2801
65 0.58 2782
70 0.75 2763
75 0.91 2744
80 1.05 2725
85 1.19 2706
90 1.31 2687
95 1.42 2668
100 1.52 2650


14.5" bbl with IBZ - 50yd zero - Same trajectory as above but with impacts out to 300yd
Q3131A (M193)


Range (yds) Impact (inch)
0 -2.6
25 -1.2
50 0.0
75 0.9
100 1.5
125 1.8
150 1.8
175 1.4
200 0.7
225 -0.5
250 -2.2
275 -4.3
300 -6.9

larry ,
let's get over the heman stuff right now..
i just find it unbelieveable that a 25 yard range is all that is available...
and if his intentions are for home defense then he should be sighting in dead on for the ranges in his house..

it's all fine and dandy on paper to try to figure out a sight in, but there are a lot of factors involved with it.
humidity,altitude, actual velocity of the round, etc.. get the picture..
unless you actually shoot the distance you will never know what the bullet is actually doing...
anyone who has tried this knows that computer/paper ballistics, really don't equate to real life shooting...


and yeah i wasted a post for that, i just can't comprehend having to live in a place where all you have is a 25 yard range..

Quoted: <snip> and yeah i wasted a post for that, i just can't comprehend having to live in a place where all you have is a 25 yard range..

And I can't comprehend being such an ass to a guy that only has access to a 25yd range.

WIZZO

im new here... but do u really need to bash this guy like that? if u dont have anything nice or helpful to say for that matter... dont say it... theres really no reason to be a complete jerkoff... get out some more buddy

oh, i'm just in a mood..
i am sorry guys and gals, i shouldn't be so harsh to him...
i actually feel sorry ...

okay so here is some help..and i do get out alot..

in my experiences, if you would sight in at 25 yards with a 55gr projectile of your choice , be it a fmj, vmax,hp,etc..
depending on the bc and sd of it, a good start would be about 2.5 inches low, with that you should be right about dead center at 50yards , with a starting velocity of about 3,000 fps. which is close to what most ammo is running, advertised velocitied rarly come close..
i know because i have a chrono..
with a 50 yard @dead center sight in, the round is still climbing due to the height of the sights over the bore..the bullets should depending on humidty, and altitude to name just 2 factors be about 3 to 4 " high at 100 yards..

this is a good start...

and again all i apologize for the harshness.. just having a rare non splatter day....as all here that know me will attest to,, i am usually more than helpful in everyway, shape and form...
so i ask for all of you all's foregivness.....

if you need farther out there ballistics, i can look at my cheat sheets i have for my ar's and get you out to 700 meters if you'd like...

the nra range here that i like to shoot gong plates at goes out to 1000 yards, but we dont shoot that distance often due to closing the range and wind....it's too tough to fight it for any serious shooting, with normal stuff,, now the 50 bmg's reign for that..

Quoted: and if his intentions are for home defense then he should be sighting in dead on for the ranges in his house..

Get a good, flat zero and learn the proper offset at the distances you might need to shoot at. The 50/200 zero is extremely flat and works well, in my admittedly limited experience (I'm a shooter, not a .Gov-man-killer) works very well until closer to 400m, where the rifle, ammunition and the abilities of most shooters start to be the limiter.

The 100m zero, for instance, places the bullets POI below the POA at essentially all ranges. It drops like a rock, in comparison.

it's all fine and dandy on paper to try to figure out a sight in, but there are a lot of factors involved with it. humidity,altitude, actual velocity of the round, etc.. get the picture.. unless you actually shoot the distance you will never know what the bullet is actually doing... anyone who has tried this knows that computer/paper ballistics, really don't equate to real life shooting...

It's not a precision rifle. If it looks anything like a real trajectory, within a few inches or so, he'll be fine. When I was zeroing at a class, the instructors got us within and inch or two at 50m and called it good.

.

Just FYI sometimes I go to the indoor range @ 25 yards to do an initial sight-in and function check because 1) I'm a lifetime member and it's free 2) It's closer 3) It's indoor so if it's raining it's no problem and 4) Sometimes it's easier initially to get on the paper and really close to sighted in at 25, at 100 you may be off the paper.  Later I'll drive down to the outdoor range.  Some people don't have access to an outdoor range!

The reason I have posted this is because although I usually shoot at a 25-yard range, sometimes I go out to my grandmothers in the country where I can shoot much farther out. I would just like to have the gun sighted in at the 25 yard range so I don't have to go out there to sight it in. The last time I went, I had quite a time, I wish I went there more often, but its muddy most of the year, and when it isn't the grass is about 3.5 feet tall, too high to see my targets. The last time I shot there, it was perfect, not muddy at all, and the field was just mowed. Since indoors is just punching paper, I would rather be sighted in to take out those milk jugs! Last year, I couldn't even nail a groundhog, I had my gun sighted in at 25. But today, I got it sighted in for 50, thanks to your advice.

I use the improved battle zero so when my rear sight is 8/3 its actually rasied 2 clicks.I sight in at 50 yds and thats good to 200 yds.I never shoot longer than 100 yds.In the real world 95% of defensive shooting takes place under 100 yds and of that 75% of the time well under 50 yds.Line up your sights like the front post is the stick and the round target the lollipop instead of resting the target circle on the post put it in the target center mass and sight it in for POI at dead center.My Marine buddie taught me that way many moons ago as oposed to most Army guys..older ones any way saying to let the target rest on the front post hence lolipop sight picture.To do the improved battle zero click to small peep there is a hole,use either .050 allen key or 1/16 cant remeber wich and put it in and un loosen a few turns until you hold your elevation drum in place at 8/3 and with the bottom part..its 2 piece raise sight 2 clicks up then retighten now when you set at 8/3 you should be able to click 2 clicks low and bottom out the sight and when you click up your new 8/3 level is right on.A proper aimpoint mount gives you the 1" of height needed to properly cowitness the red dot wich when you look through it should sit right on the top of the post depending on the type of rifle any flat top with out an F marked FSB usualy needs a .040 higher front post at least its that way on my Bushy flat top upper.

Gee, what's the standard USGI range to zero in? 25 yards. Been doing it that way for a great many years now, so thanks for your contribution.

i only have access to a 25 yard range, except for 1 sunday of every month when I have a 300 yard public range.

This thread was a great help to me! It just sucks that my rifle was hitting POA at 25 yards...now I gtg mess with it some more.

Thanks!

Quoted: Gee, what's the standard USGI range to zero in? 25 yards. Been doing it that way for a great many years now, so thanks for your contribution.

Actually it's 25 METERS (27.3yards); but it doesn't matter as the Army A2 zeroing method produces sub optimal results.  The 50y method is superior.