Hi,
People would bring all kinds of Rugers, usually fairly new, into our shop for mods such as trigger jobs and such. My old gunsmith boss would suggest to them "First, let's get the gun working the way Ruger intended it to, THEN we'll see if you need those mods." Most of the time, a good "fluff and buff" did wonders.
As that applies to the Mk II and others in the Mk series, I used the same advice he gave me when I got my 10/22: remove the extractor, plunger and spring from the bolt. With a very fine stone or sandpaper (I used 600 grit wet/dry with a drop of oil on it) deburr all the edges on the extractor (you don't want to remove metal so much as just break and smooth the edges.) It's just a simple stamped part, with zero polish/deburr work done at the factory. Check the plunger to see if it needs the same treatment. Then check and deburr the slot in the bolt where the extractor lives, clean the bejeebers out of the hole the spring/plunger ride in, give everything a wipe with a touch of oil and reassemble.
I asked him about getting a VQ extractor, and he told me this would work until I saved up the $11 or so for the VQ, which he described as "just a factory extractor that's been finished the way Ruger should do theirs." That 10/22 was purchased in late 1980 or early 1981, and as of last weekend, it was still running just fine on the factory extractor.
Rick C