I need help identifying these two 20mm rounds. The longer 20mm round has an overall length of 7-1/16" with a case length of slightly more than 4-5/16". The primer pocket is red. The case head is marked 20MM MK5. MOD. 0. RNO.7.66. The driving band is marked 20MM MK-11-1 [A] CL11-67-3. The shorter 20mm round has an overall length of 6-5/8" with a case length of 4" and contains what appears to be a primer. There are no markings. The links are marked BLM-6-10 over 6 M14A2. Are the links correct for either or both rounds?