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I think I've gotten in just a bit over my head. I have sighted scopes before, but they were ones that had been sighted before and just needed minor adjustments.

Today I tried to set up the scope on my AR and decided I'd better get some help before I mess up that expensive scope.

It's my new Colt AR6520 with a Trijicon TA01 and a RM04:



I was trying to adjust the windage on the TA01 at 50 yards before moving out to 100. I've turned the adjuster one full revolution, but it's still hitting about 4 inches left at 50 yards. I'm concerned about the possibility of damaging the internal adjustment mechanism if I go any farther.

The good news is that I have the RMR is hitting very well at 50 yards, which is the intended distance for it.

Would someone be willing to meet me at a range in the DFW area to help me adjust this? I really need to borrow someone's experienced hands.

AndyC wrote:TA01 windage is 3 clicks per inch at 100 yards - so you'll need about 24 more clicks, as 4" at 50 yds = 8" at 100 yds (therefore 8" correction needed, @ 3 clicks/inch at 100 yds = 24 clicks)

Have you bore-sighted it yet, by the way?

The problem is that I was running out of adjustment & didn't want to go any further because I didn't want to damage the internal mechanism.

I don't have a boresight for .223, so I was just planning to do it the old-fashioned way.

Last night, I removed it & made sure both the mount (integral to the scope) and the carry handle were totally clean. When I re-mounted it, I slid it back & forth in the carry handle about an inch in each direction. This was an attempt to make sure I had it properly seated before screwing it down.

While I had it off, I returned the windage adjustment to it's mid-point (or as close as I could).

I'm thinking of of ordering the Leupold Zero-Point boresighter. Midway has it on sale right now and I can use it in the future. Got any feedback on that unit? It seems to have good reviews.

1) Make sure that the Scope mount are installed correctly.
2) Use blue locktite.
3) Boresight at 50 if possible, if not start at 25 yrd
4) Get first shot on paper at 50 yrds, within 2"
5) Dial in at 100 yrds.

I would not mind helping you out with your scope on the range. I plan on zeroing my 556 (Iron sites and Red laser to 25/50 yrs) and 552 ( Red dot at 50 yrd) sometime in the next 2 weeks. Garland Public Range works for well for me. I just hope we get a nice warm weather.

Beiruty wrote:1) Make sure that the Scope mount are installed correctly.
2) Use blue locktite.
3) Boresight at 50 if possible, if not start at 25 yrd
4) Get first shot on paper at 50 yrds, within 2"
5) Dial in at 100 yrds.

I would not mind helping you out with your scope on the range. I plan on zeroing my 556 (Iron sites and Red laser to 25/50 yrs) and 552 ( Red dot at 50 yrd) sometime in the next 2 weeks. Garland Public Range works for well for me. I just hope we get a nice warm weather.

1) The mount is part of the scope's housing. It's made to go into the carry handle and is held in place by an allen-head screw through the existing hole in the carry handle. There is no other mount on this setup.

2) I will, when I'm sure I have everything worked out.

3) Already covered the boresight issue, or rather lack therof.

4) & 5) are precisely what I was trying to do.

GPR works fine for me too, but it would either have to be right after work or on a weekend. Thanks!

AndyC wrote:Ahhh, right - then you've definitely busted it. I can take it off your hands for a small fee, however...

Nice try!

AndyC wrote:If you're running out of adjustment room, then something's wrong (I'm assuming that the barrel is on properly).

Boresight first - you don't need any fancy tools for this. Cradle the rifle in a cardboard box eg with a V-shaped cutout at either end and then do something like this (aim at a small spot on the wall or something):

I'm not sure I can see well enough down the bore (it's tiny!). A long enough space to work is another problem. If we get a warm day with no wind, I could try it outside, I guess.

AndyC wrote:It shouldn't be that far off - like Beiruty asked, are the scope and mount both mounted properly?

Shortly after my first post, it occurred to me that some little piece of grit or something might've gotten between the mount & carry handle. That's why I removed the scope & made sure both the mount & carry handle are clean.

What really has me scratching my head is that this should be an easy installation. The groove in the carry handle and the matching shape of the mount should insure the scope is very close to the correct axis, shouldn't it?

Yep, if the mount is simple, it should be made to line up fine. If not, then there is a problem. The first I do when sighting in a new scope is to use the screws on the rings/mounts to line up then dial in with the scope cross hair knobs.

On the weekends are best for me for the range. I am waiting on Red dot for my 522 and some Mags that I ordered and some warm weather.

I have bore sighted a few AR rifle by taking the upper off and resting on top some yard furniture or a steady camera tri-pod, pull out the bolt/carrier and look down the barrel. I know the hole is small but the smaller picture you have the closer it will be when you make adjustments. I stood on the far side of my back yard and put a small orange sticker on the opposite fence. Get the hole in the barrel pointed directly at the orange sticker on the fence, mount scope re-align with sticker on fence and make adjustments to the scope. Or if you have your piggy back red dot sighted in at 50yds then adjust the scope cross hairs to the same point of aim.

What really has me scratching my head is that this should be an easy installation. The groove in the carry handle and the matching shape of the mount should insure the scope is very close to the correct axis, shouldn't it?

This may not exactly be real helpful to you. In my numerous years of building AR's, I have encountered a number of carry handle mounted optics that do exactly what you are encountering. The reason being that the iron sights have far greater tolerance for misalignment and so a slightly out-of-spec upper casting (with the carry handle) causes a handle mounted scope to not have sufficient adjustment to zero properly.

My not-so-great solution in some cases was to file down the affected sides and shim the scope the other way. Of course, which part to file on is the real issue - carry handle of an expensive rifle or mount of an expensive scope.

You probably know that regular bore sighters may not work on an AR with the optics that high above the bore. You can boresight using the upper removed from the lower, bolt carrier removed. Use some of those bright orange dots at about 25 yards and set the scope at the adjustment midpoint. That should tell you if you have a gross alignment problem or not. Sorry I don't have a good solution. Wish you had gotten a flat top upper.

I can't tell from the picture, are your iron sights still usable with the sight mounted? If so, are they sighted in? When I mounted my Eotech, I adjusted it to the same sight picture as my iron sights as a starting point.

A friend and I went to Top Gun his morning and I got the ACOG sighted in.

The only issue was me being too afraid of damaging the scope. I took it back to CTD last weekend and the guy had no problem adjusting it. We mounted it on a rifle just like mine and used the Leupold Zero Point. At least, if the scope got damaged, they did it!

Anyway, today it performed well at 100 yards (when I did my part) and I was even able to consistently hit an 8" steel plate at 200 yards. I ran out of good ammo, or I might've tried 300 yards.

BTW, this rifle does not like Tula hollowpoints. It was impossible to even begin to dial in the scope with it because it was all over the place. After I changed over to Fiocchi, sighting in was easy. I tried the Tula again afterwards and wasn't even getting "minute of barn door" accuracy.

Anybody want 3 boxes of Tula (white box) hollowpoints?

Glad to hear all worked out. It can be VERY frustrating to have to expensive pieces of equipment that don't behave properly.