greetings,

I've got my HK rear sight as far apart as it will go in hopes of eliminating wobble from the apeture. I thought maybe the rivet was loose, but I see this is not the case. The free play seems to be within the adjusting mechanism itself. Is it worth is to try and fix the play or just replace the assembly?

It's a $20 part.

I'd just replace it.

I've seen them at JLD,RobertRTG.com,and gunbroker.

You could fiddle with it ten times and it might fail when you
neeed it the most.

ok good answer.  thanks

Woble shold be play from the outer/inner drum (threads).  If you either pack the threads with a powder rosin (batting rosin works), or if you don't plan on re-zeroing the sights often, a single drop of Green loctite in the drum threads will take the play out between the two (don't go buck wild or you will need heat to re-adjust the sights).

Note, if the inner drum has play on the rivet, then the detent and spring are either missing or weak.  If needed, pull the rear sight and make sure that the detent ball and spring are installed.