AR shooting strangely/POA vs POI problems

[BCP]

One of my ARs is acting up and I can't figure it out. The groups open up and the windage will be way off the farther out I go. Like, groups 3" wide and 4" to the right at 200 when it was sub inch @ 100 and dead nuts vertically above the bullseye. Swapping scopes didn't do anything and the bench and targets are all level as is the rifle and scope.

The barrel doesn't have a ton of rounds through it, maybe 2000, and it's the same load I've always used that always worked (until now).

Thoughts?

edit: FWIW it is my varmint rifle RRA 20" 223 stainless

 

[Captain Kirk]

Re: AR shooting strangely/POA vs POI problems

What type of optics ? You could be dealing with a major parallax issue. Most tend to settle in behind the rifle in the same place, but any movement behind the ocular lense when your paralax is off can cause groups to open up considerably. You already verified its not scope tracking, are you using the same scope mount ? Try factory ammo ?

Kirk R

 

[TheLion]

Re: AR shooting strangely/POA vs POI problems

Parallax is my guess as well. I have a similar issue with a m223 scope as I reach out. With the m223 very slight adjustments of my checkweld had noticeable effects. Which to be honest is good at helping me keep consistent.

 

[Mike_in_FL]

Re: AR shooting strangely/POA vs POI problems

Are you reloading? If so, when this began have you had to change any of the components you use? Same powder lot, primers, bullet lot? Same brass? Did anything on the front end come loose? Shot from bipod or bags? Is the gas block clear of the FF tube?

 

[BCP]

Re: AR shooting strangely/POA vs POI problems

Nothing is loose, scopes are both known-good, one has parallax adj the other doesn't. Ammunition is good as well same batch of reloads I have been using in this rifle for a long time. I'm at a loss with this thing so I'm taking it to a friend to run a bore scope through the barrel. I'm thinking maybe the throat or muzzle has some wear and the bullets aren't leaving 100% stable.

edit: I was able to unscrew the barrel nut by hand. I guess 'nothing is loose' wasn't 100% correct

 

[997/2man]

Re: AR shooting strangely/POA vs POI problems

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BCP</div><div class="ubbcode-body">Nothing is loose, scopes are both known-good, one has parallax adj the other doesn't. Ammunition is good as well same batch of reloads I have been using in this rifle for a long time. I'm at a loss with this thing so I'm taking it to a friend to run a bore scope through the barrel. I'm thinking maybe the throat or muzzle has some wear and the bullets aren't leaving 100% stable.

edit: I was able to unscrew the barrel nut by hand. I guess 'nothing is loose' wasn't 100% correct </div></div>

Holy shit. Get your torque wrench...
It didn't make sense, known ammo, good scope, I would have asked WTF also. Cool beans you figured it out.

 

[TallShot]

Re: AR shooting strangely/POA vs POI problems

I was gonna suggest that lol....

I had a very similar issue a couple years ago, drove me nuts. I said to myself one day, the hell with it, I'm tearing it down and starting another build. Got to the barrel nut, and was like; whoa... I'm an idiot.

Tightened it up and was gtg.