Home Forums Hunting & Shooting AR and Tactical Rifles Old school guy here

I am a varmint rifle guy, definitely old school
Today a buddy stopped over with a S&W AR-15. His words were he has only mild interest in the AR-15 but since libtards do not want him to have one he bought it. He also brought a one piece scope mount and a Vortex Diamondback 4-12X scope
I put the scope mount and scope onto the rifle and we went to the side window of my shop which has a high bench for shooting at my 50 yard backstop first shot 4 inches low and 2” left. A few adjustments and the next bullet moved 2”low and a bit to the left. More adjustment and I put the next 3 shots under a nickel onto the small dot I was shooting at
I handed the rifle to the owner and he put 5 shots into a golf ball size group 2” low.
The owner lacks confidence in his shooting. He handed the rifle back to me and it shot 2” low for me 5 shots that could be covered with a quarter
I adjusted but the next shots were the same as the previous. I gave it 4 clicks up with no difference
I have heard that air rifles and AR-15 s can be hard on scopes
I have also heard good things about Vortex but also know this scope was less than $250
What do you think?
That was all the time we had to play. Now I am thinking about the next steps
The ammo was not high dollar ammo but decent. Winchester green tip 62gr

The high end Vortex scopes have a pretty good reputation.
The only Vortex I have owned was a mid level 4-16 with a canted crosshair that I returned and bought a Nikon.
I’ve never heard that AR15s are hard on scopes. I have several with different scopes on each and have had no problems.

Welcome to the world of cheap Vortex rifle scopes. Also, whoever told you AR's are "hard on scopes", are delusional.

That scope has 1/4" clicks at 100 yards.

4 clicks at 50 yards only moves the POI a half inch, well within the margin of error for a "golf ball" sized group.

Diamond backs are not exactly the best Vortex scope. When you hear good things about Vortex scopes it's generally their Razor line.

Winchester M855 gives typical groups for ball ammo, about 2+ MOA at 100 yards, so again, a 1 MOA adjustment on 2 MOA ammo, you might not see it move on paper.

Just the fact that 2 times I moved the dial 3 or 4 clicks and no change in impact when the first two adjustments were more positive

Consistent cheek weld.

Shoot enough and you will find pretty much any scope will eventually fail. Low end or premium, they all fail sooner or later.

Of course the low end have a much higher fail rate.

ARs hard on scopes?
First I’ve heard that and I’ve owned and shot them, scoped for 20+ years with zero scope problems.

3 clicks at 50 yards is 3/8 of an inch.

If you move the scope 1 click at 150 yards with subpar ammo, do you really expect to see much of difference in POI?

Are you using a proper rest, off a proper bench, or just throw you coat over the hood of the pickup?

First I would get a scope that is known to track properly.

If you have any doubts, run a box drill.

Then ditch the green tip ammo and get something that is going to actually shoot well.

ARs are not hard on scopes at all.

Bearing in mind that adjustments were made between these targets, this should give you a clue.




These are 1" squares.

The groups were shot at 100 yds using an AR with a 7 twist match barrel.

Ditch the green tip.

AR’s hard on scopes comes from the thinking that a scope is designed with recoil going one direction. As with some air guns the AR has some recoil going forward when the BCG slams home. Some scopes with light wire reticles tended to break on both air guns and AR’s along with a few other problems.

I’ve never had a scope break a reticle but that was the warning I was given when wanting to scope an AR.

TWR
Thanks. I think that is where I got the idea
I do have a SX-AR that I have put less than 200 trouble free rounds thru but that is not even a good start

He was probably thinking of AR-10s. But there are rifles harder on scopes than those too.

I've found that .30-378 Weatherbys, .416 Rigbys, .450 Rigbys, .458 Lotts, and .44 Mags are pretty tough on even the best scopes.

Not sure AR anything comes even close to these.

there are two types of Vortex scopes. good ones and bad ones. try another known scope as a control.
had the same scope on a Marlin 22 mag that would track half the time. bullseye for 2 shots then it would walk 4 inches high and right. 5th shot was off the paper.
took it back and got the thing replaced. new scope held true. not an isolated incidence.

I’m not a Vortex fan, but I currently own two. If buying new, I d stick with the Viper line on up. I do have a Crossfire that came on my Howa Mini, and it works. I had a Diamondback that was the biggest POS scope over had. Was bad from the get go.
As far as AR’s being hard on scopes, I have not seen it. I’ll be honest, I bought a cheap ass Monstrum Tactical 1-6x24, and I wish it would die. It’s the equivalent of looking through a role of toilet paper. For some reason though, it hasn’t puked on my .223 Wylde yet. Would I buy another Monstrum scope, hell no. You could probably entice me with a cheap Vortex first, at least it has a warranty.

I realize that you are only talking about a relatively few shots but could the barrel heat be affecting the shot placement and it's not a scope issue ?? Was the barrel free floated or did it have a traditional front hand guard ?

I was having some issues with 2 rifles today. Both with light barrels. Shot #1 was to the point of aim but shots #2 and 3 were an inch apart at 50 yards. The temp was about 38 degrees so each first shot was in a cold barrel.

kwg

I've been told that military spec ammo is only guaranteed 4MOA. I don't know that for a fact, so maybe some others can chime in.

I will mention an experience: My POF Renegade .223 using American Eagle M855 will group a very disappointing 4" (1:7 twist). When I swapped to Hornady 55gr SP, I was 1/2". It's a recent gun to me, so I haven't put anything else through it yet.

I'm getting ready to start working up a Barnes 70 gr TSX load as my all-around load.

The trigger on this rifle is heavy and gritty, I am not complaining about group size, The POI shifted and did not respond to adjustments
I wish he had left the rifle with me to put a different scope on it. Like I said my experience with AR style rifles is very very limited and somewhere along the line I got the idea that they were harder on scopes than a normal bolt action rifle of the same caliber

scopes are a steel on steel friction adjustment, they are manufactured and on a shelf for who knows how long, then someone buys it, puts it on a rifle and expects them to move precisely as they are supposed to.
did you turn the adjustments stop to stop a couple times before centering? Thats what I do and seldom have one fail to move, may take a while to get it tracking precisely. Thats why target turrets track better the more ya spin them.

Give the butt of the rifle a couple of bumps every time you make an adjustment. It's a way of making sure you get the adjustment . Takes a second.

I usually give the scope a few bumps with my palm after making adjustments

The problem is the POS scope.

It could have moved bit if shooting 3 or 4 inch groups it's hard to what is really going on.

https://www.shootingillustrated.com/content/green-tip-accuracy-test/