Folks,

Just got an ARMS #18 from the mail to install onto a SOCOM 16. As I'm trying to tighten down on the mount, I noticed that the top rail was not quite lining up with the iron sights. Sure enough, as there is no more to tighten down, I'm seeing the dovetail attachment is not centered nor are the iron sights centered relative to the top rail of the mount--the rail doesn't come all the way to center!

I would imagine that this would later cause a problem with mounting a scope as this would show up as excessive windage.

Is this normal?

Please advise.

I had the same problem with my SOCOM 16.  Bought an Arms18 first but the reciever was so out of spec that there was no way it could work.  Then I bought a Smith which almost fit but almost doesn't cut it.  Finally I bought Sadlak's custom reciever measuring kit and am having them custom fit one for me.  Sell the Arms and do the Sadlak custom fit it'll save you money in the long run.

Yep, it's the receiver that's out of spec, not the mount. That is the biggest optics mounting problem with the M1A/M-14 clones: out of spec receivers.

that sucks...  Would there be any recourse by contacting springfield about this?  That's unsat...

That pretty much bites . . .

On the up note, although I was tempted to take out my rasp and file, I didn't. But after tinkering around for a couple of hours I was able to line up the rail and iron sights fairly close to center (not sure how it happened). Also appers pretty much in line with the scout/barrel rail portion as well. I haven't taken a level to it to confirm, though. Not sure if I'll ever take it off now. And I did have to cut a small notch on the top plastic hand guard to fit the front set screw properly.

Thanks again for the input, everybody!