I'm wanting to buy a preban AR-15, with a flat-top and a flash suppressor. Preferably a full size, (20")? version. What should I look for in buying an AR, especically a preban version, at a gun show? (Barrel twist rate, bolt condition, how to check for wear, misuse, etc.)...

Also, what are some standard prices for ARs, (like for a blue label h-bar, this amount, for a standard sporter preban, this amount, etc.)

Slinger --

Colt's command collector's prices at gun shows.  Find a serial number listing (maybe here) and take it with you before believing any rifle is a "pre-ban."

Since you're not going to get any bargains at a gun show, and may get an illegal weapon I recommend you see what "Pete in NH" has in stock and buy from him to be shipped to your local, friendly FFL.  

As far as the actual weapon is concerned note that the typical 20" barrel is the horrible HBAR (heavy barrel) and is more than a pound heavier than the M16A2 -- and all the weight is infront of the magazine.  Heck, a 16" HBAR is heavier than the M16A2.

Unless you carry a set of nearly unobtainable gages checking for more than overall condition is impossible.

1/7 twist is first choice.  1/9 is second.  Avoid 1/12.

-- Chuck

I agree with Chuck. Check in the Equipment Exchange for your preban. Gun Shows rarely have any "deals".
I paid about $300 too much for mine. I could have gotten a better deal from a fellow AR15.com member here in the EE.
CHeck here first. Then take along a preban serial# list from Biggerhammer to the gun show.

www.biggerhammer.net/ar15/