Above are a few of the known experimental M1 Abrams tanks (there might be more that are classified...I just don't know). Want an improved M1 Abrams MBT? No problem....the issues have been worked and it only takes a look into the recent past to get either increased armor protection, drastically reduced weight or both.
Jedsite has done a fantastic job of cataloging all the known experimental vehicles and you can check it out here.
