Colt Government S70. When I re-entered the slide stop pin upon reassembly, it used to click in against the plunger tube pin. Now it just drops in silently. I fired 50 rounds through it without an issue and the thumb safety works, plunger tube isn't loose or anything. Slide stop can also easily be taken out during disassembly. All original parts, less than 1000 rounds through gun. Issue?