just a thought; but when at shows and when viewing diggers collections, there are always readily amounts of brass Bormann underplugs to be seen. And as we surmise, these are typically CS manufactured and used. But, we hardly ever see US iron plugs. Probably 50 to 1 ratio, I would guess. The US Bormann fuze is noted as being much more reliable than the CS Bormann copy, and the federals used it throughout the war. The CS copy has a supposedly dismal record of reliability, and was phased out early in the war. So... if the CS Bormann copy was ineffective, then why do we see so many brass plugs from blown balls ??
And I can only figure we only seldom see iron federal plugs because diggers don't know what they are and think they are just a rusted washer or something not worth keeping to them
Did the Federals use brass underplugs too ??