Need Help sighting in my AR

[Ranger Dave]

Just bought a flat top AR and put a NcSTAR detachable rear sight. Now how is the best way to get everything sighted in. I would like to have it sighted for 100yrds but only have 50yrd range.

[Solus]

Just bought a flat top AR and put a NcSTAR detachable rear sight. Now how is the best way to get everything sighted in. I would like to have it sighted for 100yrds but only have 50yrd range.

If you know the velocity of the ammo you will be using, preferably when fired from your rifle, but close will come close, you can use a ballistic calculator set to a 100yd zero and look at the chart to see how much above the sight line it should be at 50yrds.  

Then you can set your sights so you are hitting that high at your 50yds target and it will be close to a 100yd zero.

[tombogan03884]

Zero it for 25 yards and it will be on at 100. the trajectory of the bullet makes it even out.

http://www.armystudyguide.com/content/army_board_study_guide_topics/m16a2/zero-and-m16a2-rifle.shtml

http://www.modeerhunter.com/stories/zero.aspx

http://www.abousainc.com/SightIn.htm

It won't give you bullseye accuracy from my experience, but it will be close enough for any other purpose.

[Ranger Dave]

Just got back from the range, sighted in at 25yds. Shooting well enough for now am trying to post pics.
Thanks
Ranger Dave

[Ranger Dave]

Here is the rifle
this is 25yds benchrest
this is 25 standing the two high shots are at 50yds.

[Sponsor]

[tombogan03884]

Looks good.

[twyacht]

Sometimes those A4 front sights can be a tad high or low with the addition of a different rear sight....Looks like you won't need the front sight adj. tool at all....(they're cheap, so get one anyway),....

Good call, and good shooting. I was going to throw a laser bore sight it the mix, but as others posted, start short (25yds.) and I've even tried 15, get it "happy" than the printing at 25-50-75-100 becomes a quick adj.

My AR is red dot zeroed at 50, but I kinda built it for that, anything closer or out to 100 is just a reflex from there, and is minute of paper plate. Every time, all the time.

Mine's not designed for 4-leaf clovers at 100, but zombie elimination.

Take care,

tw

[tombogan03884]

2 Things TW.
1) the 25 yard zero should be on at 100 may need tweaking for cloverleafs but close enough for any other chores like hog hunting.
2) You don't need a tool to adjust the standard AR  sight, it's built to be done with the tip of a bullet, front and rear.

[twyacht]

2 Things TW.
1) the 25 yard zero should be on at 100 may need tweaking for cloverleafs but close enough for any other chores like hog hunting.
2) You don't need a tool to adjust the standard AR  sight, it's built to be done with the tip of a bullet, front and rear.

As usual, the McGyver overcome and adapt of sight adj. is also a very valid point as tom stated.

Thanks tom.