I agree with you regarding the Naval Postgraduate School thesis. If their data suggests a BMP-2 has 450mm of protection, that is clearly an error in their simulation model, and I am happy to discard that specific source to maintain quality standards.
However, I have to push back hard on your interpretation of the CBO Report , the Federal Register , and the timeline regarding the SEPv3.
“Heavy Armor” is a Proper Noun, not a generic adjective.
You argued that “heavy armor” in the CBO report is just a generic description of weight. You cannot cherry-pick the usage of the word “heavy” from a paragraph about air transport weight limits to disprove a technical designation in a specification table.
The Federal Register (Vol 63, No 134, July 14, 1998), a primary federal legal document, explicitly defines the term.
Title: "Proposed Finding of No Significant Impact (FONSI) for the M1 Abrams Main Battle Tank Heavy Armor System "
“This EA focuses specifically on the assembly, use, repair and disposal of the heavy armor package… The current use of the depleted uranium (DU) armor package on the Abrams MBT has been re-evaluated.”
In 1998, the Army legally defined “Heavy Armor System” and “DU armor package” as interchangeable terms. Therefore, when the 2006 CBO Report (Table A-1) lists “Heavy armor added to hull and turret” for the M1A1 AIM, it is using the official Army nomenclature for the DU package established 8 years prior.
If “heavy armor” were just a generic description of weight as you claim, the IPM1 (which gained weight over the M1) would be listed with “Heavy armor” too. It isn’t. It is listed as “Improved composite.” The CBO uses specific technical designations in that row, not adjectives.
The SEPv3 Timeline is Impossible.
You stated: “By then [2016] the newest variant was the SEPv3, which we know is confirmed to have DU hulls.”
This timeline is factually incorrect.
The M1A2 SEPv3 did not enter Full Rate Production until late 2020 .
The NRC License Amendment in question is from 2016 .
The CBO Report citing “Heavy Armor” in the hull is from 2006 .
The Federal Register confirms the “Heavy Armor” cut-in happened in 1996 .
You are suggesting that a CBO audit from 2006 and a production cut-in from 1996 are referring to a tank (SEPv3) that wouldn’t exist for another decade. The NRC license covers the operational fleet (M1A1 SA and M1A2 SEPv2) that was circulating through depots at that time.
The Federal Register explicitly states: “In 1996 , a design change to the armor package was made by the Army and cut-in to production… effective with Job #1 M1A2 Phase II .”
That “Job #1” refers to the M1A2s built 25 years ago, not the SEPv3. The “Heavy Armor System” (DU) in the hull has been the factory standard since 1996. Linking the Devblog about the “5 school tanks” relies on an outdated 2006 license limitation that was superseded by the later amendments authorizing broader possession.