Glock 19 versus Sig Sauer 229 which one is a more dependable weapon under extreme abuse condition?

Sig all the way. Sig is the only pistol that can fire with a bullet stuck in the barrel (specification of the Seals). The sig is less prone to jams with limp wristing because of the steel frame. The sig has fully supported chambers. The sig won't crack in the -50 of alaska.