Three Sided Hollow Bases

[nkbj]

What do yall think about this design that was shown on a recovered relics website?
Was it a means of insuring that the base didn't shear off and leave a ring in the barrel?

 

[nkbj]

 

[Whitworth]

It's a French import. I've got one kicking around here somewhere.

 

[nkbj]

Yep, French, like in post #2.

Anyone have ideas on the engineering?