This picture shows a C&S drum on the right and an early Vector drum on the left. The early Vector drums used copper tubing for the dummy rounds which were later replaced by Swedish practice rounds. Rex at Vector told me that the Swedish ammo was so cheap for them it was actually cheaper to use it than the copper tubing. The C&S drums use aluminum dummy rounds. Dummy rounds are required to push the last rounds up in the mag tower.
This picture shows the Vector drum on the left with the ring welded on the back to prevent you from accidentally releasing spring tension on the drum.
As you can see from these pics the welding of the Vector drums are very nice. But it did not run as well as the C&S drum. The C&S has been flawless for me since day 1. It can also keep up with the high ROF of the MINI Uzi which is pretty impressive.
Making these drums yourself looks to be a pain. Mike Maguire made these type of drums for the MP5 and the 9mm Colt. I watched him work on one and it doesn’t look fun. The Uzi/MP5 both normally use a double feed mag. These drums change it to single feed. So a plate is welded in the feed tower to make all the rounds feed from the right side. “Tabs” also have to be welded in place to keep that plate in the proper position.
This picture shows the newer generation drum that I received from Vector using the Swedish dummy rounds.
Even after receiving this second drum from Vector, I still had feeding problems and decided to send it back since I had a perfectly working C&S drum.
Note that the latest version of the Vector drum I had seen used metal dummy rounds that look just like the ones in the C&S but more shiney. Maybe made from SS?