20 x 102mm PGU-40/B Dummy, U.S

Picked this up at SLICS (available in quantity), 20 x 102mm dummy, only markings are on the projectile: GLN14A852-002 20MM. GLN = Galion Inc., Galion, Ohio, 14 = 2014.
Projectile body is magnetic, dummy nose fuze is nonmagnetic.
In the cartridge base is what appears to be a large button head screw which is nonmagnetic (stainless steel?), the hex slot is filled with what appears to be grey epoxy.
Cartridge case is brass.



This is the ‘new’ 20MM PGU-40/B dummy cartridge.

Found a text about it was for testing the LALS with brass cased dummies

" The current use dummy cartridge, the PGU 39/B, features a steel cartridge case which is considerably more rigid
than the standard brass 20mm M103 cartridge case. When the Linkless Ammunition Loading System (LALS) is
tested, evaluated or checked out with the PGU 39/B, such is not a truly realistic evaluation, e.g., 20mm service
ammunition contains brass cartridge cases exhibiting higher flexure. The purpose of the brass cased 20mm dummy
cartridges is to more closely mimic service ammunition during testing, evaluation, and checkout of the LALS
system. "

Brian, great pictures, thanks for posting. As mentioned above by Geert, this is a PGU-40/B dummy and the most interesting fact about it is that is was made by MAST Technology, Inc. The case markings seems to have almost dissapeared in this specimen -some remains are visible below the shoulder- but these includes the manufacturing symbol “MTL”. Regards, Fede.

Fede & Geert,

Thank you both for filling in the details on this cartridge. Upon closer examination there is a hint of printing on the cartridge case, which may have been removed, as all the rounds for sale that I looked were without obvious printing on the cartridge case. I have changed the title of the thread to reflect the proper designation for this round.


PS - Did a quick web search and found the Federal Business Opportunity web listing for a contract award to MAST Technologies, Inc. on September 28, 2012 to manufacture 20mm Dummy Cartridges, PGU-40/B, in M548 Ammo Boxes, 100,000 cartridges each, for the U.S. Navy.

I believe MAST is now being run by Jim Bell’s son. Jim was the owner of B.E.L.L. Brass specializing in British & out of production bras for numerous other firearms. Also, at one time, made plastic bodied 40mm practice grenades for the Govt. among other things. Used to come to SLICS but Haven’t seen him in a couple of years. A very nice gentleman & free with information.

They’re also available at “Guns & Surplus .com” for $11:

gunandsurplus.com/Inert-Ordnance … dge-Bullet

I’ve been meaning to pick up a few.