Unknown Case


I obtained this from a friend who was in the Air Force and whose job was to keep F16 and A10 armed I got the 30 mm and the 20 mm but I do not know what this is?
39.48 mm inside diameter
46.03 mm case length
15.00 mm primer diameter
43.63 rim diameter

thanks Vic


looks like a fired 40mm grenade case . Must be several hundred if not a thousand variations. At least two case major case lengths, one short for the troops & one longer for helicopter use. I’m speaking generally here as someone has probably interchanged them in some system or other.


Pete, the 40mm long casings are now used in the Mk 19 automatic grenade launcher. The Corps has had them since around '83 when they went to Beirut.

The casing shown looks to be for 40mm’s used with the M203 or M79.


Not to forget the MK47.

In short there are two types.

The so called “LV” (low velocity) in 40x46. Used in weapons like the M203 and M79 and all related types all over the world.

The so called “HV” (high velocity) in 40x53. Used in automatic grenade launchers like the MK19 and MK47 and many others.

There a new one upcoming called the “MV” (medium velocity) which shall be the successor of the LV. It will use the same case (40x46) but has a higher velocity and the weapons will be new ones. As I understood the development was initiated by FN in Belgium. They still have problems to get an acceptable recoil with weapons using it. I wonder if that one will go anywhere.


Ummm so now it’s 1003 vaiations,
Thanks bacarnal! & EOD


EOD, Been out for 10 years and haven’t heard of the Mk47. Looked it up on the IN. Is everything going to Video Games? Seems no one can use Iron Sights anymore.


Bruce, yes, it seems so. I recently had a look at one and found it overdone. Maybe those having used it can tell us more on the advantages of it.