[charlie98]

I understand to do some work and parts upgrade but at this time I am not willing to put any money or effort into it.

Well, then, you might as well sell it.

It's shown that it is capable of fine accuracy, obviously something is heating up/moving/binding/shifting/etc once you start really shooting the thing. This is not uncommon and I won't bore you with the maudlin details of all the squirrely firearms I've gotten that required some detective work and a few parts to square them away, but to me the effort was worth it. And this is not to say something like this wouldn't happen with the next M1a no matter what make you would get.

If you are frustrated with it, set it aside for a while or sell it. And, as the others mentioned, maybe get another set of eyes on it... you might be staring right at the problem and not see it.

 

[charlie98]

45.308,

My recommendation,

Remove the optics.

That was also my first thought. I never put an optic on my rail, in fact, I removed the rail on mine, completely. The way the mount is, right on the barrel, right in front of the chamber... that is probably the worst place to put a mount.

...and check the adjustment screw on the rear sight... mine came loose when I was shooting last week... took me a while to figure it out. Duh.

 

[charlie98]

That was also my first thought. I never put an optic on my rail, in fact, I removed the rail on mine, completely. The way the mount is, right on the barrel, right in front of the chamber... that is probably the worst place to put a mount.

I love quoting myself...

Now that I think about it... with your optic mounted on the Socom16 rail... which is mounted on the barrel right in front of the chamber... and you are having issues with wandering zero or shotgun patterns after a few shots. That optic mount turns into a heat sink and what does hot metal do? It expands... or at least tries to.

I'll also say that when I shimmed my gas lock correctly my POI shifted 5", but my groups tightened by 50%.