ACOG BZO

[Fr0ntSight]

I spent three hours trying to zero in my new ACOG today but couldn't quite get it. I keep reading online that you need to tap on the dials after making an adjustment. Has anyone else experienced this? I'm going back to the range tomorrow to give it another shot but don't wanna spend 3 hours with no improvements If any of you have any tips PLEASE share

FS

[Gunfighter420]

At what range are you starting your BZO? I had a ACOG and I started at 25 yards to get on paper. I then moved to 50 yards and zeroed it again. After my final BZO was at 100 yards. If you start at 100 yards off the bat, your wasting ammo just trying to find yourself. And yes you should tap it after every adjustment to seat the prisms.

[Fr0ntSight]

I got new BUIS also and at 50 yds was able to get 1/2" MOA in like 10 min no problem. Tightened it down then threw on the new ACOG. Put my target out to 100yds and looked like it was shooting low left...so i made some adjustments ( no tapping ) but couldn't quite see POI (no spotter, and not the best eyesight) so i kept shooting till the next ceasefire and shots seemed all over the place...every few shots i would be dead on but it felt like it wasn't consistent at all. Tomorrow I'm going to take your advice and start at 25yds and move up slowly with tapping. Thanks for the help !

[Gunfighter420]

I'm sure you been shooting for awhile and know all the fundamentals. My son had the same problem when setting BZO at 100 yards on his rifle. If your pretty much zeroed in at 50 yards with some nice groups, usually the farther out you go its all about trigger control. I told my son to not anticipate the hammer drop expecially at 100 yards cause any little movement has a big effect at that range. It helped him and I'm sure you already knew that

[Fr0ntSight]

Sorry...I meant I was zeroed in with my irons...i didn't shoot the ACOG anything less then 100yds But your ABSOLUTELY right about the fundamentals and how important they are at distance. I really wish I had tried at around 25-50yds though. Tomorrow the plan is start at 25yds then slowly move back and whack the dials after each adjustment. Could the tap on the dials really cause this much of an inconsistent group? Also, do you know why the tap helps? The Trijicon manual I have mentions nothing about it..but it seems to be common knowledge for AR guys online. Plus tomorrow I'm bringing a spotter! That should speed things up a bit

[Gatordev]

What kind of ACOG are you using? If it has a cross-hair w/ BDC, the manual mentions putting one of the BDC reticles on the bull at 25 or 50 yards (I can't remember which and don't have the manual here). That will get you pretty close and then you can move out to 100 and put the main reticle on the bull to refine your zero.

I haven't shot a Chevron or Donut type reticle for an ACOG, but I'm guessing you can do the same thing since they also have the BDC.

[Fr0ntSight]

It's the TA31RCO-M4

[morthrane]

The manual for the TA33 red chevron has the 25m zero using the upper tip of the vertical red line below the chevron. I made the mistake at first of using the top tip of the chevron for my 25m zero, which made 100m shots a handful (3-5?) of inches too high.

No issues with adjusters, no need to whack them so far but its only been a couple hundred rounds.

OP, what have you done to isolate the shooter as issue while zeroing? I've found that my own behavior has far more influence on grouping than the optic-- just breathing wrong or holding my breath seems to negatively influence grouping, let alone trigger jerk, fatigue, or any one of 101 ways to ruin accuracy. It sucks to waste ammo chasing a POA/POI that's constantly on the move because of the shooter, not the ammo or optic.

[Fr0ntSight]

So I went back yesterday and think I finally have it dialed in. I took gunfighters advice and started closer at 50yds got it zeroed in then moved out to 100. A few things i did differently this time was I banged on the sight after each adjustment and I bought 62gr ammo instead of the 55 i was using before. I am going to upload a couple pics of the target from 100yds but i think its good enough.....I think the rest is just human error..breathing, trigger control, follow through, etc...let me know what you guys think. Should the sight perform any better than this from 100yds on a somewhat windy day? The first pic was my first mag and the second was after i adjusted only 1 notch left to adjust. Thanks again for all of your input!!!

FS

[Fr0ntSight]

I also emailed Trijicon to get an explanation on the tapping after each adjustment and will post their reply as soon as I get it.

FS

[Fr0ntSight]

Trijicon response

So I finally got a response, albeit a vague one, from Trijicon. They said you should indeed tap after each adjustment IF the scope is new. I requested a bit more information and will post it as soon as I hear back from them.

FS

[Press Check]

While this obviously is not the case with all ACOG's, some do in fact need to be tapped, which resets the prism.

For those that don't know, ACOG's are set at 100m when they leave the factory, so realistically, you should have automatically been on paper at 50m to 100m. From there, you should be able to attain zero within 10 rounds or less.