Rifle Scopes Parallax problem or scope problem?

[billyjo]

I've lurked on this site for sometime, I've been shooting for quite a while but I have a problem and I need some input. I recently bought a Armalite AR10T carbine and have been trying to find a load to shoot in it. I started with the factory FGMM 175SMK and it didn't shoot them well. Then I tried reloading the 175 SMK with IMR 4064 still not very good luck. I could get groups down to an inch but had vertical stringing.

I decided my problem had to be parallax and searched and read everything that I could find on the subject. The part I don't understand is from what I've read you can't have the absence of parallax in the horizontal without having it in the vertical. It would seem from my observation and my target today that I have NO parallax in the horizontal but I do in the vertical which goes against what I've read.

The middle target was the first one that I shot and I definately wasn't driving the gun like I should have been. The second target (on the left) after the 2nd shot I got on the gun the way I should've been. The third target (on the right) I drove the whole time. I shot the 2nd and 3rd target nose to charging handle.

Anyway the only way I can account for the vertical stringing, since I can't seem to dial it out is parallax. I can see the change by moving my head in the vertical while the horizontal stays stationary. The scope is a Leupold LR 6.5x20 50mm with side focus. The targets were shot off a bipod front and bag in the rear if it matters. The first shot after the bolt is closed is always low, after that they seem to group together if I do my part.

Any input on why I have the vertical stringing would be appreciated.

Thanks,

Bill

 

[sobrbiker883]

Re: Parallax problem or scope problem?

Cheek pressure on AR platforms is pretty unforgiving. Have you had anyone else shoot your rifle?

 

[Lowlight]

Re: Parallax problem or scope problem?

That stringing is on the extreme edge of what might be considered a parallax issue, the target image would probably be completely out of focus and the reticle would look like it was sailing on Hurricane Earl Seas, so chances are it's not that.

As stated 308 semi auto rifles are very unforgiving to shooter error as well some rifles just don't like certain rounds.

While it could be a scope issue, I would recommend looking else where for the root cause.

 

[billyjo]

Re: Parallax problem or scope problem?

I haven't had anyone else shoot this rifle. I have other gas guns and this is the only one that I have a problem with but I will let someone else shoot it to see if the results are the same.

To get the scope to where there is no parallax side to side the target is by no means clear. To be honest I can barely see the bullet holes @ 100 yards on 20 power when I have the side to side parallax adjusted out. Even then I still think I have vertical parallax.

Where else would I look to find the problem? Barrel is free floated and the mount is tight.

Bill

 

[jdgray]

Re: Parallax problem or scope problem?



<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: billyjo</div><div class="ubbcode-body">I haven't had anyone else shoot this rifle. I have other gas guns and this is the only one that I have a problem with but I will let someone else shoot it to see if the results are the same.

To get the scope to where there is no parallax side to side the target is by no means clear. To be honest I can barely see the bullet holes @ 100 yards on 20 power when I have the side to side parallax adjusted out. Even then I still think I have vertical parallax.

Where else would I look to find the problem? Barrel is free floated and the mount is tight.

Bill

</div></div>

Parallax is parallax, if you got vertical, you got horizonal.

 

[billyburl2]

Re: Parallax problem or scope problem?

If you are having that much of a problem with parallax, sounds like maybe your reticle diopter might be out of focus. The reason I say this, you stated the target is out of focus when the cross-hairs quit moving.