Going to a gun show this week and I'm new to AR's.
I just want to know what i should look for in a used AR?

thank you

i'd be kinda disinclined to buy a used ar at a gunshow if i wasn't highly capable of inspecting it myself.

you will find some VERY good folks on the EE

Ok,  how do I buy a used AR-15

Look at the outside of the gun.  
Is it clean?  
Look for pitting, funky paint like non anodized finish (spray paint)
Is the pistol grip and butt stock tight?
Is the front sight straight up and down?
Do the pins for the trigger and hammer show more wear than the lower?  Like they have been beaten out several times with a hammer?
Is the upper and lower reasonably tight or do they have a lot of play?

Check all features.  Dry fire.  
Now check the disconnector.  Hold the trigger back and Pull the bolt back and let it go.
Now release the trigger.  Did you hear a click and the trigger reset?.  
Pull the bolt back and slowly lower it to see if it binds on the hammer.  If it hangs up halfway thru lowering it then that’s bad.

Open the gun up.  Pull the bolt out.
Look at the face of the bolt.  Is it pitted?
Look at the trigger group.  Is it clean and neat or dirty or rusty?
Cock the hammer.  Pull the trigger and catch the hammer before it strikes the lower (you can damage someone’s gun if you let it fall.)
Hold the trigger back and manually cock the hammer.  There is a little hook that holds the hammer back called the disconnector.  Is is making positive contact with the back of the hammer?

Look at the buffer.  Is the face of the buffer heavily warn?  

Look at the inside of the upper.  There is a tube that comes from under the hand guard  and sticks into the upper is the tube running straight down the channel or is it toqued to the right or left?



Buy a little light to inspect the barrel.
Look for pitting, rust, and dirt.

Quoted: Going to a gun show this week and I'm new to AR's. I just want to know what i should look for in a used AR? thank you

This is quite tough, as mentioned above, your chances of detecting a good "used" buy at the fun-show will be in direct proportion to your ability to detect "parts is parts" built rifles from factory original rifles.

Definitely not something a neophyte should attempt (not that you are one, but dealers there are not quite as up-front with those that they ID as such, some have no scruples at all and will sell ya junk, that they know is junk, just to get rid of it), it's just that even experienced AR aficionados can at times overlook details like cheap parts and mis-matched components.

My advice would be to contact folks on your Hometown Forum, and ask them for help as for certain a few will be attending and rely on them to help you with your choice. There are a lot of great guys here with loads of knowledge, that will insure ya get what your paying for.....

Most will be more than happy to help, I'm sure.

Mike

PS - of course if your a former military armorer or Colt/Bushmaster/RRA/DPMS AR factory employee, disreguard everything I said, as you've probably forgotten more about ARs than we ever knew in the first place......

thanks for the replies.
My buddy has one that i can shoot and i watched him take it apart but his was new.
I was gonna buy a kit and stripped lower for around $590 but if i can get a better deal at the show then i could save some money.  
From reading on the this forum and from watching him take his AR apart i believe that i could check everything that was listed above.
The show is this Saturday, so i will let you guys know how i made out.

thank you