Let me educate you all on the safety detent spring

[Continental Op]

They are incredibly small and they like to hide in carpets! 

[copemech]

large magnet on a stick from harbor freight!

[whitecap]

Most people don't even realize that its gone or where it went to begin with. CGW has the unit in stock. Copemech has a great idea. If you keep tinkering you will need it again.

[SI VIS PACEM PARRABELLUM]

I've never had an issue with the safety detent spring. That little devil of a hair spring for the fpb lifter is a different matter altogether.

[afultz075]

A pair of electronics tweezers makes removing/installing detents and springs a breeze:
https://www.amazon.com/Hakko-3-SA-Non-Magnetic-Microelectronics-Applications/dp/B00FZPEWI6/ref=sr_1_12?ie=UTF8&qid=1466182239&sr=8-12&keywords=electronics+tweezers

[Continental Op]

I've never had an issue with the safety detent spring. That little devil of a hair spring for the fpb lifter is a different matter altogether.

Oh, that one's gotten me, too!  I've lost several springs over the years and I've found every one.  I am clumsy, but tenacious. 

[1SOW]

I use a large speaker magnet.   My wife says, "Not again!"

[Indy_Tim]

The easiest way to ensure you don't lose these springs is to by spares.  Before I had spares, I spent a lot of time crawling around looking for the darn things.  Now that I have a set of spares waiting, they seem less likely to wander away from the bench.

[Tim_B]

Just do what I did and take a pair of needle nose pliers and squeeze the end coil of the spring a bit so it fits tighter on the safety plunger thing and won't come off unless you intentionally pull it off.  You have to pinch the coil with the spring removed then place it back on the safety detent plunger.  I also do this with the plunger springs of all my 1911's so the two plungers with the spring in between them come out as a single unit.