From the US Army's FY2022 budget documentation:
"The Abrams Tank Production Program upgrades existing Abrams tank variants to the M1A2 SEPv3 tank configuration in order to enhance tank survivability, lethality, and mobility while improving overall system reliability and durability. The M1A2 SEPv3 incorporates turret and hull armor upgrades, mine blast improvements, reactive armor tiles, lightweight belly armor, improved countermine equipment, Improvised Explosive Device (IED) jamming equipment, a Total Integrated Engine Revitalization (TIGER) engine, an upgraded transmission, an Auxiliary Power Unit (APU), improved power generation & distribution, Ammunition Data Link (ADL) for smart munitions, Embedded Training, Blue Force Tracker, Block 1 Second Generation Forward Looking Infra-Red (FLIR) technology, and improved computer systems with Line Replaceable Modules (LRMs) to include microprocessors, high-definition color flat panel displays, increased memory capacity, Gigabit Ethernet, and a new operating system designed to run the Common Operating Environment (COE) software.
The Abrams Tank Production Program funds the costs required for the daily operation of the production plants producing M1A2 SEPv3 tanks and components. The Abrams Tank Fleet Modification Program applies Materiel Developer and Combat Developer approved modifications to the fielded Abrams family of vehicles either through field modifications at the unit or through application during vehicle recapitalization. Common Abrams modifications include Active Protection Systems (APS), lethality enhancements to fire the latest smart munitions, gun tube durability improvements, vehicle smoke, Network upgrades, GPS enhancements, cyber security measures, Power Train Improvements, safety improvements, light weighting, and any other modification identified in existing requirement documents or validated by the Army. Funding is also used for recurring improvements for Industrial Base facilities and their components by focusing on planning, maintaining, improving, optimizing, and modernizing contractor's manufacturing facilities."
What is involved with :"gun tube durability improvements"? Possibly a new alloy or manufacturing process?