tips on zeroing a red dot on an AR for 100 yards

[30 cal slob]

well, went out to the range and tried to zero an aimpoint comp red dot sight for my .223 AR.

it was boresighted before i left.

was all over the place, couldn't even get on target at 100 yards. was pretty embarassing. did all sorts of things from trying to eyeball the POI on the berm (spot dust plumes) etc.

i cut my session short after shooting 25 rds of M855PD (feder/lake city 62 gr green tip). i understand this ain't the greatest ammo, but i suspect i'm doing something wrong.

help?

thx.

-slob

p.s. if there are any economical alternatives with slight magnification as an option, i'm all ears. i was looking at the leupold mk4 cq/t (1-3x) but got sticker shock and few seem to have it in stock anyways.

p.p.s range won't let me shoot centerfire rifle at a 50 yard target.

 

[rero360]

try cowittnessing the red dot to your irons if you have the ability to do so, that should get you pretty close. I've never been all that good with red dots, just good enough to put holes in the pumphouse doing CQB drills

but i would imagine that it would be like normal scopes, focus on the dot and have the target fuzzy,

 

[briansmithwins]

Check for looseness: scope, scope mount, barrel.

What groups does the rifle shoot with iron sights? If you get 3" groups with irons and 3' groups with the dot, you know it's not the rifle.

What type of red dot are you using? Some (like the $20 types) just will not hold a zero.

Start real close in, like 5 yards. At that range your POI should be about 2.5" below your POI, but windage should be dead on.

I use and recommend a 50 yard zero. It's the most flexible and takes advantage of the 5.56 NATO cartridge's flat trajectory. More on 50 yard zero here: http://groups.msn.com/TheMarylandAR15ShootersSite/improvedbattlesightzero.msnw

BSW

 

[pgeleven]

What type of red dot are you using? Some (like the $20 types) just will not hold a zero

couldn't be more true, my $125 ATN sh#t-the-bed on me before AND after i sent it in to get a warranty fix. some optics aren't meant for the AR bolt carrier slap

i agree by referencing your iron sights in respect to the dot, that would be your best bet. first-time red dot operation can be a bit tricky sometimes. if you dont have iron sights i have 2 solutions that have worked for me in the past:

free solution: get closer to the target so you can figure out where the round is going, use the pistol side of the range. or,

not-so-free solution: buy a lower-cost laser boresighter and align it

just understand with a red dot, dont expect to hit the wings off a fly at 100 yards, be happy with a small group. its meant for close-quarters and quick target acquisition, not tack driving