What's new
British Ordnance Collectors Network

This is a sample guest message. Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Unknown 20 mm drill/ballast round.


Well-Known Member
Help guys!!
Had this kicking around & still no idea as to origin!!
It is 20mm & case is 95mm. Base 25mm
Made from a heavy steel alloy -almost like white metal & it is slightly bent. Base is a sttel insert threaded & bonded with two op[posed flats for a spanner.
It is cast & has DCMT 54 BALLAST & a dimple castembossed in it.
Projectile is 73mm so o/al length is 168mm.


  • DCP01564.JPG
    96 KB · Views: 87
20 mm ballast

These rounds were used to fill ammunition boxes in Aircraft .They weigh the same as a live round but are obviously a lot safer.When aircraft are being test flown the C of g is the same as a fully armed aircraft. I have seen these rounds in 30mm Aden but not 20mm.
Hi ,
I have one of these as well though it doesn't have a base rim , just a beveled base.

I understand these were used soley as ballast rounds and not for gun functioning or feeding ,hence no need for an extraction rim.

cheers Rob
20mm hispano variants
ballast,drill,SAPIR,SAPI,HEI,BALL,TP french electric primed


  • 131.jpg
    97 KB · Views: 67

refer to 20mm hispano SAPI(R) in Projectile thread.
Had me a bit concerned when i first got this as i knew (?) yellow signified explosive and blue meant inert or training .
Fortunately got hold of the correct Air Pub. before i got carried away and handed it in!.
cheers Bob.
I've got some similar rounds. The base is just flat and closed off. They came from a Shakleton that had been retired from the RAF in the 80's.