OP,
If you are considering a 9x19 or 22LR top end assy for that P229-
You will need the P229-1 top end assy.
Or a conversion barrel of the same designation.
A Sig 40S&W barrel will drop in the slide using the same Blue color coded recoil spring & magazines as 357SIG.
A P228/P229 9x19 top end assy would require changing the locking block.
An SResetT for a P226,227,228,229 will enhance trigger reset,consisting of an SRT sear & SRT firing pin safety lever.
An SReachT trigger if smaller hands & reach are required.
P226,P228 magazines will latch into the P229 357/40 frame & function properly.
His is the "E-2" version they come equipped with the SRT
