German 3,7 FLAK

[josephc]

I believe this to be pretty complete; what are the threads for on the inside bottom of protectile? Can anyone attribute a dollar value to this Flak piece?

[Kevlar]

I can't help you with the value, but the threads at the bottom as you describe them is something called cannelures.

Source: http://www.dtic.mil/get-tr-doc/pdf?A...c=GetTRDoc.pdf (page 39 for cannelures)

I'm not sure, but my best guess is that it's purpose is to keep the bullet/projectile steady in the air and to maximize velocity.

[Frundsberg]

Around 100 euros in Europe. Maybe a little bit more in UK and USA.

[cat66]

I paid 100 US dollars for mine

[TonyE]

I can't help you with the value, but the threads at the bottom as you describe them is something called cannelures.

Source: http://www.dtic.mil/get-tr-doc/pdf?A...c=GetTRDoc.pdf (page 39 for cannelures)

I'm not sure, but my best guess is that it's purpose is to keep the bullet/projectile steady in the air and to maximize velocity.

The cannelures on the outside of the shell below the driving band are for crimping the case to the shell. They have nothing to do with ballistic efficiency.

The poster wanted to know about the threads on the INSIDE of the shell base, These could be for a strengthening base plate but more likely to receive an external tracer capsule.

Regards
TonyE

[josephc]

Thank you. Joe

[Matt L]

Yes, they're for the screw-in tracer cup; I got a loose one for the 3,7cm shell I had some years ago to really complete it.