In CT the Barrett M82A1 was banned for years.  Now that there is a loophole I want to get one before our POS governer makes that illegal again.  How do I tell if a Barrett on the auction sites is older or a preban?  I've seen some differences in the muzzle device and what is the serial number cut off?

Thanks

Ask for a pic of the serial number of the barrel, bolt and bolt carrier. If they are all pretty close, nothing has been replaced and you have a close date of production.
Bolts and barrels are serial numbered together through the proof testing process to match back up after magnufluxing.

The bolt and barrel will be dated  12/2014  for example this month's production but have an individual number prefix .
Can't remember, but I think bolt carriers have just month/year date stamp. It also helps track heat treat lots.

If a radical change in serial numbers in parts is evident, a part has been changed from the original. Your only recourse is to call customer service at Barrett and ask to see when the rifles born on date was.

Receiver serial number is the only determinant of "pre-ban". Part serial numbers won't matter in the least, matching or not.

Find out the serial number and call Barrett. They will tell you. If it is in fact pre-ban, then send a letter to them asking for confirmation in writing. You will want that and a reputable FFL wil want that proof.

I realize the actual serial number will determine whether or not it is preban or not. I was letting the OP know a quick way to look at his rifle and geusstimate his rifles date of manufacture.

I appreciate both answers.  I visual clues help, but does someone know the serial cutoff?

You'll have to contact Barrett for that. You don't want to be wrong...

I called Barrett and they said they will mail me a litter stating that My 82A1 was made and shipped to my FFL dealer before the ban.
What else do I need to sell it to a ban state ?

That's all you'd need.