Starting around the time that the GI Mil Spec was introduced, Springfield was struggling with a run of bad extractors. The problems ranged from dimensional spec issues to poor heat treatment and not holding tension.
One of the dimensional problems was in the front pad behind the claw causing the claw to sit too close to the breechface centerline, and placing too much of the tensioning wall into the breechface feedway...which increases the amount of extractor deflection as it picks up the rim.
After a close look at BladeRunner's breechface, it appeared to have about .015 inch of deflection...which isn't as much as some I've seen...but just enough to cause an intermittent failure to go to battery. I like to see .010-.012 inch, so...to err on the side of caution...I cut .003 inch out of the tensioning pad, and removed a like amount from the claw to address any possibility of the claw bottoming out in the case extractor groove, and cut a light camming bevel in order to let the rim to allow it to open the extractor more gradually.
The correct deflection allows a good bit of tension on the extractor, and although the .003 inch cut did reduce the tension a bit, the expedient shake test indicated that there was enough.
The other problem that I spotted was that the previous owner polished the feed ramp in the attempt to get the pistol to feed, and he rolled the top corner slightly. Fortunately, the damage was slight, and a few test feeds from the magazine with one finger pushing the slide and the recoil spring relaxed satisfied me that the bug was probably squashed. His one failure to go to full battery on the top round during a slidelock reload indicates that recutting and contouring the barrel ramp may be in order. After he shoots the gun a bit more, we'll make that call. It's also possible that a bit more cut out of the extractor tensioning wall will do the trick.
What we've learned here is that sometimes the standard "Do this/Check that" troubleshooting doesn't always address the problem. Most feed-related issues can be traced straight back to the magazine. If the magazine proves good, the next thing to look at is the extractor.
All too often, the advice is to reduce the tension, but if the deflection is excessive...you can reduce tension until the case falls off the breechface and still have return to battery problems...and that's where a lot of the trouble starts.
After adjusting tension without satisfactory results, our boy's next step is to grab a Dremel and have at the feed ramp...and we've already found out where that usually winds up. If the bullet nose enters the chamber at all, the feed ramp isn't even part of the equation any more.
1. Once that material has been removed, it can't be put back, so before you file, cut, grind, sand, or polish anything...be sure that all other possibilities have been eliminated.
2. Learn to think outside the box. Very often, the "standard" advice doesn't apply.
3. Leave the feed ramp alone. Mirror polishing isn't necessary as long as the angles are to spec, and Dremel Dan wrecks those angles more often than not.
BladeRunner...You can cut and paste this post to the other forum if you want.