FWIW I sent my OG TiRant 45 to AAC last week for a “rebuild “. $60 and three days later it’s in the mail back to me.
It was “pre-21” so not covered under current lifetime warranty.
It had many, many rounds though it and while fairly clean, carbon or something got in the 3-lug system and I could not get the hub/piston/lug assembly apart. I tried for weeks; soaks, solvents, heat. It initially un- threaded about 1/3 of a turn, but then locked up solid. Best $60 I have soent in a while. The $35 return shipping made me sad.
ZY