Way back in the day I was switching out the ambi mag release on a Ruger P90 .45ACP pistol [I'm a leftie].
You guessed it, the spring went sproing & was [temporarily] lost. The flooring in the room where I was doing this was variegated carpet. Hands & knees & even going over carpet with magnet there was no success. So, ordered a new part from Ruger. It came in the mail, eventually, replaced it & all was good with the pistol.
Much later, was doing some reloading in said room. Dropped a piece of brass on carpet, bent down to pick it up & what was seen right next to it? Yup, that errant little spring from weeks before!!
You can't make this stuff up!!
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NAA.