Need help zeroing AR iron sights

[jgalt]

I've never done this before, so I've got some questions:

1. The main purpose for this rifle is home defense, and the longest shot I could possibly take in my current home is about 30 feet. This leads me to think I should probably zero it at 25 yards? If not, what distance would be recommended & why?

2. Do I need any special tools to adjust the front post? It is a standard AR fixed front sight base... (Rear sight is a flip-up Troy BUIS)

3. Is there a preferred position to use, i.e. prone or bench? Other? I assume the use of sandbags is recommended?

4. Anything else I am missing?

I will eventually be putting on some type of non-magnified "red-dot" sight, but it won't be for a while.

I am not looking for any "hands on" help (though I probably won't turn it down if it is from someone who really knows what they are doing!) - a link or 3 to good, solid info is all I really need. I am more than willing to learn through trial and error on my own. I've done some searching already and haven't found anything I really like yet - though I'm continually amazed by my total inability to use the correct search words to find what I'm looking for

Any and all help will be greatly appreciated - thanks!

[elmerfuddem]

"1. The main purpose for this rifle is home defense, and the longest shot I could possibly take in my current home is about 30 feet."

How close is your nearest neighbor?

Google this:sighting in ar 15

[jgalt]

How close is your nearest neighbor?

1. If you want to debate ballistics data &/or the pros/cons of using an AR vs. Shotgun vs. handgun for home defense, please start a different thread...

2. Your search suggestion was helpful - thank you!

[ex-LT]

Sight it for 50 yards. At 30 ft, you're only going to be a couple inches off (below) zero. For anything larger than a chipmunk, that's going to be more than accurate enough.

[Stradawhovious]

If you are zeroed at 50 yds, and are using 55gr ammo (assuming 3,000 fps), you will be good to go with +/- 1" from point blank to 200 yards. FWIW

[jgalt]

My home defense ammo is Hornady TAP, 5.56, 75g BTHP @ ~ 2700fps. Does it make a difference?

(The question is not opening a debate on my choice of ammo, just on whether or not it makes any difference in sight-in procedure...)

[jgalt]

Sight it for 50 yards. At 30 ft, you're only going to be a couple inches off (below) zero. For anything larger than a chipmunk, that's going to be more than accurate enough.

If you are zeroed at 50 yds, and are using 55gr ammo (assuming 3,000 fps), you will be good to go with +/- 1" from point blank to 200 yards. FWIW

I'd like to think I'd only be taking a shot inside if my target is in fact bigger than a chipmunk... Unless it is a really evil chipmunk.

Based on other things I've read, it looks like the difference between 25 & 50yd zeros is that the corresponding zero will be either 300 or 200 yards respectively. Right or wrong?

Why choose the 50yd zero over 25yd?

Either choice uses the same process to achieve the actual zero, right? So once I pick a distance at which to zero, the steps will be identical?

Thanks all so far - keep the advice comin!

[Stradawhovious]

By the looks of it, with 75gr boolits moving at 2700fps if you zreo at 50, your corresponding zero will be at about 160 yds. At 200 yds you will have a little better than a 2"drop. If you zero at 25 yards, your corresponding zero will be at around 280. The big differencte is that at around 125 to 150 yards you will be a solid 5" high on your target, whereas with the zero at 50, at 150 yards you will be no more than about a half an inch high.
(these numbers are based on my calculator, for those of you in the know, please feel free to correct me if I am wrong about this.)

I think, for my personal preference, 1/2 inch high at 125/150 yards is a lot more acceptable than 5" high. FWIW
This is neither here nor there though, for shots under 30 feet, set it wherever the heck you want.

[elmerfuddem]

It don't matter what you set your zero for if you can't see your sights. You said home defense weapon right?
Get yourself a set of night sights, then zero your rile: http://www.gunaccessories.com/ar15/AR15nightsights.asp

[jgalt]

It don't matter what you set your zero for if you can't see your sights. You said home defense weapon right?
Get yourself a set of night sights, then zero your rile: http://www.gunaccessories.com/ar15/AR15nightsights.asp

Not helpful - I've got what I've got right now, and need to make do with that right now. I will get some type of optic whenever I can afford to do so...

[jgalt]

By the looks of it, with 75gr boolits moving at 2700fps if you zreo at 50, your corresponding zero will be at about 160 yds. At 200 yds you will have a little better than a 2"drop. If you zero at 25 yards, your corresponding zero will be at around 280. The big differencte is that at around 125 to 150 yards you will be a solid 5" high on your target, whereas with the zero at 50, at 150 yards you will be no more than about a half an inch high.
(these numbers are based on my calculator, for those of you in the know, please feel free to correct me if I am wrong about this.)

I think, for my personal preference, 1/2 inch high at 125/150 yards is a lot more acceptable than 5" high. FWIW
This is neither here nor there though, for shots under 30 feet, set it wherever the heck you want.

Thank you very much! Is there a good on line calculator I can use to do these calculations myself?

[elmerfuddem]

It don't matter what you set your zero for if you can't see your sights. You said home defense weapon right?
Get yourself a set of night sights, then zero your rile: http://www.gunaccessories.com/ar15/AR15nightsights.asp

Not helpful - I've got what I've got right now, and need to make do with that right now. I will get some type of optic whenever I can afford to do so...

Some of the "red dots" will light up your AR and your position like Rudolph. Some won't.
Sorry it wasn't helpful, but it does get dark here in River City.
If you fear for you safety, talk to some of the instructors on other steps you may take to protect your abode.

[Stradawhovious]

I downloaded "Ballistics Lite" for my Ipod touch.

[jgalt]

It don't matter what you set your zero for if you can't see your sights. You said home defense weapon right?
Get yourself a set of night sights, then zero your rile: http://www.gunaccessories.com/ar15/AR15nightsights.asp

Not helpful - I've got what I've got right now, and need to make do with that right now. I will get some type of optic whenever I can afford to do so...

Some of the "red dots" will light up your AR and your position like Rudolph. Some won't.
Sorry it wasn't helpful, but it does get dark here in River City.
If you fear for you safety, talk to some of the instructors on other steps you may take to protect your abode.

Thanks for the suggestions. I know it isn't obvious based strictly on writings on an internet forum, but I have done a number of other things that will hopefully keep me from ever having to pull the trigger of any weapon I own in defense of my home. Getting the sights zeroed is just one of the many things that needs to be done, and that is up next on my list.

I'd like to think that I don't have an "unreasonable" fear for my safety - just the normal, prudent amount...

Thanks again.

[ex-LT]

I use this....

http://www.remington.com/products/ammunition/ballistics/remington_shoot_ballistics_software.asp