Update
So, I have my first and so far only complaint - after running a couple of cartridges through the action/mag, I noticed the characteristic "Mauser" cuts on the brass from the underside of the mag lips (which out of box were sharp enough to cut skin if you moved too fast) - no biggie, some 1500 grit on that edge to round it did a pretty decent job. I may do another round on it (1000? 800?), but I don't like messing with feed lips on Mauser actions since they play a role in lining the nose up to the chamber.
HOWEVER, and worse - the chamber/breechface is shaving rounds on me. I thought it was the uppper edge of the feed ramp, so I 1500'd that too, until I looked at the breechface and saw a pile of brass shavings sitting under it, right after the feed ramp/lug. The breech edge was causing 5.5mm wide scrapes along the brass - only a thou deep, but enough to feel with a fingernail and potentially cause issues reloading. I also found that I could push the round halfway to 3/4 of the way into the chamber (so the rim got to the boltface), then retract the bolt and it would leave the round in the action - so the round isn't getting to the boltface smoothly. The other concern is this was actually scraping the jackets off the bullets too.
Some research led to this being a common issue with the M77 Hawkeye action - the extractor is too tight/extractor claw is too long for the boltface, so it keeps the round pushed down when it should smoothly slip onto the boltface. Since the rounds don't make it all the way onto the boltface, they stay "hugged" along the feed ramp and drag on the mouth of the chamber on the way in.
I took the bolt out and "pushed" a round under the extractor - which needed some GOOD finger pressure and a very authoritative "CLICK" when it settled - enough that when I took the case off the boltface, the claw edge left a definite gouge/dent in the extractor groove.
I tried sanding the claw down with the 1500 (I didn't want to go a stronger grit and over-sand the claw or miss and damage the boltface), and it didn't do much besides remove the finish on the extractor. Should I send the rifle to Ruger or is there an easier DIY "dress up" to loosen up the extractor? I read somewhere that hitting the extractor behind the collar with a rubber mallet can "ease up" some of the pressure on the nose - but I don't know how well the cast parts would take to "Bending" pressure like that, and since the claw on a 77 action sits farther forward than a more traditional Mauser pattern, would the pressure behind the collar be enough to pull it back a bit on the front?
Also, does the extractor claw have to be putting pressure into the extractor groove to work? Does a "loose" extractor on a Mauser action cause issues?
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Update - found This link:
http://www.gunsumerreports.com/review_ruger_m77-gs_p4.php
Described complete takedown and removal of extractor for 77 Hawkeye...I forgot it's so dang similar to the M96, M98, CZ 550, etc etc. Turn out of extractor retaining groove, slide forward off collar. Also neat they used a more "flexable" collar - seems it may help in allowing some "give" in sliding over the edges of cases.