I am looking for Mini-14 thirty round magazine base/floor replacement. My internet search has been exhausted; neither Ruger, Midway, or Brownells have them in stock. Anyone know where to find them?

I’d check Numrich Gun Parts.

When I was looking for the newer anti tilt Mini 14 followers I think the only sources were the ones you listed & Numrich, but had to wait for someone to get them back in stock. I just got on the ‘notify me’ list for Midway & Brownells. Can’t remember who got em in first but both places notified me within a week so I’m assuming Ruger just released em in batches.

Check https://www.perfectunion.com/vb/ruger-mini-14-mini-30/.

Thanks I looked there, midway USA, and Brownells, and no cigar

Try Sarco.  Or go to Perfect Union, and find out which company MAKES magazines identical to yours.  Maybe identical floorplate is used in smaller-cap, presumably cheaper, easy to get mags

Phone the Mfr--no e-mail--, and ask them to sell you what you need.  Nothing ventured, nothing gained.

Put up some WTB ads here in EE, and elsewhere, for a floorplate that will serve.

Contact Ruger. Last time I had problems, they said to send them in and they'd make good on em.

They are five after market 30 round magazines (Pro Mags) I bought during the dark years of 1994 through 2004. They were always problematic, and because of them, I bought six Ruger 20 round and six Ruger 30 round magazines. Bought it always bothered me I couldn’t get them to work right, that I completely rebuilt them using Ruger OEM followers, Wolf extra power springs, and Perma Slik them after degreasing them. When I was taking them apart three of the magazine base plates broke, and I used spare base plates from AR’s to see if they work. Believe it or not, they work well now except the base plates look ugly.

The mags work OK with spare floorplates?  You are  doing this for cosmetic/appearance purposes, and not because the mags are currently useless?

They kind of slide a bit plus they are open at the bottom so dirt gets into mag body if I drop them while shooting in the desert

Tape up the bottom of the mag, and call it a day.  Leave a small hole for water drainage.  Bonus points if you use 550 cord to make "Ranger Loops": https://onlygunsandmoney.com/?s=evolution+of+the