Just installed my first free float handguard. It is a MI M LOK 12" and installation was straight forward. The only issue i see is the top rail of the handguard bottomed out on the receiver before it could nottom out on the barrel nut. My question is: Is this normal/common/acceptable? It seems to be aligned propperly in every other way and seems to be quite secure. There is a small, about 1/32" gap between the rear of the handguard and the teeth of the barrel nut. The alignment tabs are engaged and i dont believe it will move. I just wonder if this is something I should correct with barrel nut shims or by filing the rear of the handguard rail, or am I creating a problem out of a non issue?

Non issue.  Most people want the top rail to butt up against the upper receiver.  I have 5 or 6 MI SSK and Gen 2 rails and none of them bottom out on the barrel nut.  That is the way they are designed to ensure the top rail does bottom out.

Thank you sir. This was my first install and my OCD was getting the better of me.
On an unrelated topic...... how the heck do I upload pictures to a post?

You need a host server like Photbucket.  You open a free account, upload the pics to PB, then copy/past an IMG link to your post that you want the picture to show up in.

Thanks again bud. I am interweb challenged at times.