Sort of about replacing. Well, yes. Anyone interested is putting a reflex sight on any semi-auto?Well, 2 of my Glocks have the factory tritium ones on them, those are steel.
The other 2 had the plastic ones, but not any more (1 has Ameriglo operators, other has Trijicons) The Glock plastic ones really suck. The G19's lasted for about a year, then the front sight started spinning. The 17L's rear (adjustable) sight broke within a week + the front one got loose in a hurry. Rather than send it back to Glock for a new set (that'll last 6 months maybe) I just put in the Ameriglos.
If you're thinking about replacing your plastic ones...DO
Check out www.sight-mount.com This small picatinny rail attached with there screws. (requires
drill and tap) Then any reflex sight can be attached (choose one with a picatinny mount)
So anyone can have (well, close) a Sig X-FIVE pistol on the cheap. The Sight Mount folks are
great to do business with.