So I was swapping stocks out on my Mini I keep in the basement workshop, went to eject the round and it barely came out, very uncharacteristic for a mini. Took the bolt apart and couldn't find the extractor spring. It was frozen in the extractor spring channel badly rusted with all kinds of gunk in there. I managed to pry it out, soaked it in a spoon of oil, put it on a pin and held the other end with vise grips and hit it with a little dremel wire wheel and my drill. Cleaned up pretty good.  I used this guys video for reference: https://www.youtube.com/watch?v=FTYXmiUzQk8

I keep my guns impeccably clean so I thought, have no idea how that got so corroded in there but it's back to ejecting rounds four feet again till I can find a new spring.

Something to keep an eye on if your the least bit mechanically inclined as Ruger would have wanted the whole rifle for an easy fix.

Posted elsewhere and a different context, but may be useful here:

"Given the age of your rifle, and possibly its mechanical condition, I strongly suggest you seek out some essential spare parts for it. Ruger no longer supports the 180 series of Mini-14, and IIRC, some earlier series Minis have diminished support from Ruger. Parts to obtain include (but are not limited to) extractor, ejector (and all their associated parts and springs), firing pin, and Op-rod spring. Note that a Mini-14 in good mechanical condition does not need any sort of "Extra-Power" springs.

Some of these parts may require the parts to be fitted to the Mini; the Owner's Manual will indicate "fitted" parts. Long ago I sent my 186 series Mini back to Ruger for fitted parts, and I have never regretted it. There may be other options nowadays, such as ASI. I store all the parts in the hollow stock (synthetic) of my Mini where they can never be lost."

Note that Ruger takes a very dim view of user-installed mods, so I strongly advise removing such mods prior to shipping to Ruger.  Periodic cleaning of the bolt (inside and out) with carbon-cutting spray and compressed air may serve to reduce/eliminate problems such as experienced by the OP.