Crayford queries.

[SG500]

Attached are a few pictures of some 40mm Crayford rounds.

The one on the left is a "standard" one for comparison purposes.
The one in the middle has a very unusual profile. When unscrewed the base is solid copper. I know of one other round idential to this one.
The one on the right is rimless. I know of 2 other rounds like this one.

Does anyone have any further information on these unusual Crayfords. The 2 rounds on the right do not appear to be standard and do not have any markings on them. I am assuming that as there are other similar rounds out there that came from completely different sources that these are genuine and not made up rounds (they certainly feel and look like real ones).

All inert and legal with nothing nasty in them.

Dave.