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)
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:
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.
Serial numbers that end in "D" were duplicates and one was changed using this letter.
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.
"Older" does not always mean pre-ban as per Corey Sattler.
"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.
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.
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).
Who's next? Syria
Isaiah 17:1The burden of Damascus. Behold, Damascus is taken away from being a city, and it shall be a ruinous heap.