Since I haven't seen this posted on the new site yet, though it probably has been, I am submitting it for future reference.

Lot's of people ask about their AR's serial numbers, and whether or not their rifle is pre or post ban. Well here's the break down.......

[red][size=5]AR-15 Serial Number List[/size=5][/red]

Disclaimer:  This list is correct to the best of my knowledge. [blue]ALL SERIAL NUMBERS SHOULD BE VERIFIED FROM THE MANUFACTURER PRIOR TO ANY PURCHASE OR ASSEMBLY[/blue].

If any information presented here is found to be incorrect or you have additional information to contribute, please contact me so I can make the notations/corrections here.

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

[red]American Spirit Arms[/red]
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.

[red]Armalite/Eagle[/red]  (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.

[red]Bohica[/red]
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.

[red]Bushmaster[/red]  (800)998-SWAT or (800)883-6229
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

[red]Century Arms[/red] Lower
Marked CIA.  All are Post-Ban.  Made with Olympic Arms Receivers under contract.

[red]Colt[/red]  (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

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

[red]DPMS[/red]  (800)578-3767
Below 10300 - Pre-Ban.
Some or all lowers are cast.  Black in color.  Some lowers are Stainless Steel.

[red]Eagle Arms[/red]  (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.

[red]Essential Arms[/red]
All are Pre-Ban as they went out of business in 1993. (DPMS bought them prior to the Ban)  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.

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

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

[red]J.L.M & Sons*[/red]  (603)425-1860
SC001 through SC250 are Pre-Ban.  All others are post ban.

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

[red]Military Manufacturing (M2)[/red] 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 - 18 deg magazine angle and square mag release.

[red]Nesard[/red]
See "Sendra" below.

[red]Olympic Arms[/red]  (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 through 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.

[red]Professional Ordinance[/red]
All are post ban (including all of the pistols).

[red]PWA[/red]  (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.

[red]Rocky Mountain Arms[/red]
Producer of AR-15 type pistols.

[red]Sendra[/red]
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

I have posted this before, do not rely on the S/N only, just remember it's not you who determines if pre/post but the ATF.

Check the web site listed at end of post.
Ron

1.Almost all Eagle Arms rifles bearing the notation "Eagle Arms Div ArmaLite"
  are post-ban rifles.  The only exception will be on serial numbers under
  30,000.  Receivers with pre-ban serial numbers marked with the ArmaLite name
  are new receivers produced to repair legitimate pre-ban rifles.
2.Many Eagle Arms lower receivers were sold to customers and assembled outside
  the factory.  ArmaLite has no way of knowing which of these arms were
  legitimately assembled into "pre-ban" rifles before the Crime Bill went into
  effect.  
3.ArmaLite's history specialist will conduct research into the
  production history of a given serial number and provide a letter attesting
  to its factory designation and shipping date.  The research will be
  conducted at a cost of $25.00 per firearm.  The customer name CANNOT be
  provided due to privacy constraints.

Also note that simply because a given lower receiver has a "pre-ban" serial
number does not necessarily mean that the firearm was assembled prior to the
ban, only that the receiver was manufactured before the effective date of
the ban. In order for an assault weapon to be "grandfathered", it must have
been configured as an assault weapon prior to the ban (the effective date of
the ban was September 13, 1994.) If a stripped lower receiver was in a dealer's
bound book at the time the ban took effect, and it is later discovered in an
assault weapon configuration, it could be rather easily ascertained that it
is not a grandfathered firearm. Receivers in private hands on the day of
the ban are a little more ambiguous as who is to say if it was or was not in
an assault weapon configuration on the date of the ban, and then later stripped?
As always, buyer beware.

Link for more info:
http://home1.gte.net/bblakley/ban/

If anyone is wondering what you get for this, it is a form letter signed by the president of Armalite that says, for example:"Serial number ##### was originally shipped to Utah in June 1996 as a pre-ban M15A2 M4C carbine." Then it has a disclaimer that Eagle sold many pre-ban lowers and doesn't know which of those were assembled into legal pre-ban rifles before the deadline. The letter goes on to say what features are legal on pre/post ban rifles.