How can i tell the the difference?

To determine whether a rifle is truly a pre-ban, assuming that's what you're looking for, you can tell by the serial number on the rifle.

The rifle had to have been made in to a COMPLETE rifle, by the company prior to the 94 cut off date.

Get the serial number, and either call the company who made the rifle and ask them....or, there are lists of different companies serial numbers before and after the ban available on the web.

Who makes the rifle you're looking at? With any luck it's not an Olympic Arms. They're the only company who will find it almost impossible to tell a pre from a post ban. They had a fire in their main facility a while back and lots of docs were lost.

P.S.- The vast majority of all AR's you'll see in gun shops today are post-ban AR's. You need to provide a little more specific information to have a more detailed answer given.

A receipt of sale dated pre-ban is good enough for the government, or so I'm told.

Advanced Armaments
No information - Apparently machined from bar stock aluminum, lowers are marked as M-15.

American Spirit Arms (Formerly "Sun Valley Traders")
ALL lowers are Post-Ban. Began introduction of lowers and rifles in mid/late 1998. Noted as having good fit & finish. Also, reported to be manufactured by Lewis Machine & Tool.

Armalite/Eagle 800-336-0184
Slightly over S/N 30,000 was the Pre-Ban cut-off, call to verify.* (Some Eagle lowers below the 30,000 range were determined to be POST ban by BATF - call to verify) Armalite sells Eagle lowers, but sells factory complete rifles with Armalite lowers.

Bohica
Made stainless steel lowers, rumored to have also made AR-15 pistols. Lower marked M16-SA. This is NOT verifiable info as it came from the Internet. Out of Business.

Bushmaster 800-998-SWAT
Below L051000 - Assembled Pre-Ban Rifles and some pre-94 lowers.**
L051001-L063000 - Mixed Pre-Ban Assembled Rifles and Pre-Sept 94 Lowers (Call to verify)
L063001 and Up - Post-Ban

Century Arms
Lower marked CIA. All are Post-Ban. Made with Olympic Arms Receivers under contract.

Colt 800-962-COLT
CC001616 and Below - Pre-Ban
CH019500 and Below - Pre-Ban
GC018500 and Below - Pre-Ban
LH011326 and Below - Pre-Ban
MH086020 and Below - Pre-Ban
NL004800 and Below - Pre-Ban
SL027246 and Below - Pre-Ban
SP360200 and Below - Pre-Ban
1963 SP00001-SP00023**
1964 SP00101
1965 SP02501
1966 SP05600
1967 SP08250
1968 SP10750
1969 SP14000-SP14653
1970 SP15001-SP15473
1971 SP16001
1972 SP19401
1973 SP24201
1974 SP32601
1975 SP43801
1976 SP55301
1977 SP67651
1978 SP83400
ST038100 and Below - Pre-Ban
TA10100 and Below - Pre-Ban
BD000134 and Below - Pre-Ban (AR-15A3 Tactical Carbine - very rare model)
MT00001 and Above - Post-Ban
BK000001and Above - Post Ban (CAR-A3)
CST000001 and Above - Post-Ban (Began Late 1997 Production)
CMH000001 and Above - Post Ban
CCH010000 and Above - Post Ban MT6700, MT6700C and MT6700CH series, 1998 production

Dalphon (360) 427-6867
All are POST ban. Cast 356-T6 Aluminum, hardcoat anodized per mil-spec A-8625

DPMS 800-578-3767
Below 10300 - Pre-Ban.
Some or all lowers are cast. Black in color. Some lowers are Stainless Steel.

continued...

Eagle Arms 309-944-6939
Now called ArmaLite. They will not give out a list, but will look up on an individual basis. Lower receiver serial numbers DO NOT begin with EA.

Essential Arms
All are Pre-Ban as they went out of business in 1993. (DPMS bought them prior to the Ban) Call DPMS Lower receiver serial numbers begin with EA. Some or all lowers are cast. Light gray coloring. It is rumored that Ruger investment casted the lowers for Essential Arms.

Frankford Arsenal
All are pre-ban. As rumor has it, Olympic Arms produced the lowers for Frankford Arsenal Call Olympic Arms and then Frankford assembled the weapon. A2 configuration lower. Frankford Arsenal went out of business in 1987. (Info from [email protected])

Hesse Arms
All AR-15’s are post ban. Manufacturing began late 1997/early 1998.

J.L.M & Sons* (603) 425-1860
SC001 thru SC250 are Pre-Ban. All others are post ban.

Knights Armament Co.
All AR-15’s are post ban, very few AR-10’s are pre-ban. No further info at this time.

Military Manufacturing (M2) (FAX 702-263-7875)
All were military/law enforcement only. Full auto lowers were standard, semi were optional. Lowers were machined form raw bar stock with improvements incorporated - 18deg magazine angle and square mag release. (See: http://www.m2corp.com/HOME.htm)

Nesard
See "Sendra" below.

Olympic Arms 360-459-7940
4-numbers only - very very old. Probably machined from bar stock. 1-letter and 4# - older receiver, but forgings. (Some are newer, POST ban castings - call to verify.) 2-letters & 4# - most receivers follow this pattern. 2#, 2 letters, 4# - the first two #'s are year of manufacture of the lower. 2 letters, 6# (separated 2 & 4 - e.g. SA 96 0000) - first 2 #'s are year of manufacture. "ICR" marked lowers are an European customer’s overrun, has an unused additional hole - all ICR lowers are post ban.
Olympic Arms Manufacturer’s Notes:
1. There were some odd variations and some custom serial numbers mixed in thru the years also. And, some receivers manufactured after the ban have the year stamp after the model name, not in the serial #. And if you don't see a year stamp on the receiver, it is not necessarily pre-ban.
2. Serial numbers that end in "D" were duplicates and one was changed using this letter.
3. Recently some serial numbers have left with one or two letters followed by FIVE numbers. The last numbers are either 5's or 0's. 99.9% of these are post-ban.
4. "Older" does not always mean pre-ban as per Corey Sattler.
5. "BL" serial number series lowers are transitional with some pre and some post ban. If you have a "BL" you’ll have to call to verify for certain.

Professional Ordinance
All are post ban (including all of the pistols).

PWA (360) 438-3983
35222 and Below - Pre-Ban (Note:Some lowers are cast not forged. Out of business) Post-ban have a year prefix in the serial number. Rumored to have only sold lowers.

Rocky Mountain Arms
Producer of AR-15 type pistols.

Sendra
Post-ban receivers have a circle milled into the side of the magwell. They were originally bead-blasted to a non-glare finish. All others are pre-ban. (This is unverified info…) Also, they used to be NESARD. Rumored to have been owned by Dick Drasen (currently M&A Parts) and produced lowers only out of Barrington, Illinois. No complete guns were sold (again, unverified info).

there is also a $1000 or multiples in difference. i dont think anyone mentioned that.....