Calling Glock experts again...

[Buddhabelly]

Can I put the extended slide stop, mag release, Ghost trigger kit and springs from my current G19 in a G21SF?

[21SF]

Nope

[HighLander51]

Don't know about the slide stop or trigger, but the springs should work, and the 'extended' magazine catch is just a G21 stock part. check this parts listing at Brownells.

http://www.brownells.com/.aspx/pid=0/sid=858/schematicsdetail/Models-17-39

[CrippledPidgeon]

As highlander said, the extended Glock 19 mag release is a standard Glock 21 release (so swapping will do you pretty much nothing). I don't know what trigger kit you have, but if it's just a connector, it should work. Springs may be iffy. Slide stop, probably won't fit, it looks like Glock lists two different part #s for small and large frame pistols.

[SDM44]

Trigger will work, but nothing else.

I have both a G19 and G21SF and have extended mag releases and slide stops on both, along with messing with the triggers.

Ironically, the Ghost trigger I used in the G19 (feels great in that) does not feel good in the G21SF. I'm running the stock trigger in mine and that feels smooth.