I’m after any info this 7.7cm round. I have x4 normal glass bottles for this round and x1 shorter bottle of same diameter BUT don’t have any info on. I do know the germans used two other rounds the 10.5cm and the 15cm that used glass bottles. I have been told there only about 300 of these bottles left in the world. if any one can offer any info on these rounds that would be help full.