What 20mm drill cartridge is this?


Added this to my modest “collection” today, but I am a little confused…
Case lenght is 110 mm.
Case diameter at head (rim) 24,8 mm, below shoulder 24,2 mm.
Bullet diameter is 19,4 mm (body) 20,75 mm (driving band) 19,6 mm (forward copper band).
Cartridge length 187 mm.
Bullet stamped with Bofors logo (B with a horisontal arrow through it) and 46, under that a script N or V.
The open tipped brass inert Fuze unscrews and has a small locking screw in its side, projectile is hollow and has an open bottom, with a narrow flange.
~7,8 mm Berdan primer pocket.
It might be swedish, but the 20 mm autocannon M/40S we had back in the forties shot rimmed ammo.



Soren, this is a 20x110 HS 404 case with a 20x145R M40 projectile. Nickel plated and stuffed together to look good.


John, this is the Bofors logo.



EOD - Thank you. I could not see from the photo, on my screen, that the letter was a “B.” I could only see the verticl line dissecting the arrow’s shaft. Check out page 60 of Franczyk’s “Polska Amunicja Strzelecka 1919-2004,” down in the lower left corner. You will see the similarity of the Polish Mint Mark with that of Bofors. Sorry about that. I get into trouble everytime I wander into these threads outside of my own auto pistol specialty.

I will delete my previous answer, as it adds nothing to this thread, now that I know what the actual mark is on that 20 mm dummy. Well, what do you expect - a dummy writing an answer to a question about another dummy! Sorry about that.


John, I knew that Polish logo and figured that you misread the Bofors logo since it is easy to happen when one is not into Bofors.
After all you do not need to apologize for a simple missunderstanding, it happens to all of us.


[quote=“EOD”]Soren, this is a 20x110 HS 404 case with a 20x145R M40 projectile. Nickel plated and stuffed together to look good.[/quote]Ok I follow you but: Why? -why take a very rare projectile body and stuff it into a rather dented chrome plated (not nickel) Hispano 404 case, roller crimp the case neck around the projectile bottom after turning a deep cannelure above the boattail. Seems like a lot of trouble to create a non-existent round of 20 mm ammo.
I’ll keep it and call it: Fake swedish air force drill cartridge.


Those projectiles are remnants of the demil operations of the Swedish stocks of 20x145R. These projectiles float around every now and then and I have even seen them turned into cork-pullers.
Note to worth that the cases as per Swedish regulation get a hole punched into the side as part of the demilitarization process. That may also explain the absence of 20x145R cases in general.
I would assume that your Hispano case is a fired one and not a demilled one. Such things also appear when people without interest in ammunition try to make a souvenir or just something that “looks cool”. Pimping desktop ornaments by chrome plating is also not uncommon. Have seen many rare items being ruined this way.

As human nature is he tries to stuff any holes with anything on hand, that also goes for ammunition and creates so many “bastard” cartridges.
I know plenty of people which consider themselfes to be collectors (certainly no researchers) which can not stand to see a case without a projectile or vice versa, what then follows is just sad.


Another reason to repeat your question:


Just to round it all off (pun intended)



Good point, can you tell us anything about the Danish made components?


Hmm. I have two 20x145R Bofors cases but only one projectile (a short AP type). My other case would love one of those long HE projectiles if there are still any going spare…