U.S. Munitions 12 ga. "BLOCK BUSTER" Shell & Box

Below are photos of a plain white 25 round box for 12 ga. shells with spars information rubber stamped in black ink on the front of the box.
The red plastic shot shells are low base brass (brass plated steel?) and the case is marked “BLOCK BUSTER” along the side of the plastic hull.
This belongs to a friend and in my haste I forgot to take a photo of the headstamp, but as I recall it was somewhat generic without a specific name.
In the last photo you can just barely see through the plastic hull what appears to be some shot (#7 size or there about) mixed with small plastic beads/granules.


U.S. Munitions is mentioned twice in the IAA Journal:

#393 page 9-

#469 page 39 shows a drawing of an all plastic shotshell attributed to U.S. Munitions

Can anyone provide additional information on U.S. Munitions?

My assumption is the BLOCK BUSTER round was an attempt at a door breaching round for the law enforcement market. Can anyone confirm this was the manufactures intent for this loading?

Any feedback, corrections are most welcomed!



1 Like

That should be a sort of cheap AP type of load (they’re all cheap in 12ga), meant as something to fire at an engine “block”, hence the name. Some of these were nothing more than a large steel ball bearing in a cup, while others were cheap slugs with a steel rod core. Some call these “gun show loads” of the sort like tracers & incendiaries which are aftermarket boutique made for gun show types of sales. What loos like small birdshot should actually be powder that leaked up a bit and is visible through the hull.

1 Like


Great information!

When the opportunity presents itself I will test the cartridge with a magnet.



Hi Brian, great box, thanks for sharing. The headstamp of this cartridge is 12 ☆ 12 ☆ 12 ☆ 12 ☆ (case made by Cheddite).

This was a short lived company that only existed between the early 1990’s (1991?) and 1996, when it became Pacific Cartridge, Inc., who continued offering “US Munitions” cartridges and also had a headstamp of their own: PACIFIC 12 USA 12.

US Munitions made several special loads, but also standard cartridges. An interesting variant is the Sioux Empire Cartridge Collectors Association (SECCA) 1994 commemorative.

Som examples:


SECCA box:



1 Like