Bout 500 or so rounds thru my sr40. After a couple mags it sometimes fails to extract the casing all the way from the chamber. I feild strip and clean often. Hoping I don't have to send it away. Let me know what u guys think.
First step is to check the extractor and look for buildup of "crud" or possible damage.
It takes surprisingly little dirt under the extractor hook to make it release the casing too early. Another possible explanation for the pistol to suddenly start having extraction problems is damage to the extractor - use a bright light and a magnifying glass to look at the hook to see if a bit has broken off.
Your chamber could be nasty. Use your favorite bore cleaner to give the chamber a good scrubbing. Often extractor damage is hard to spot. Sometimes you only see a shiny spot on an extractor that appears to be undamaged. I would not hesitate to send the gun back to Ruger. If the gun is new Ruger will pay shipping both ways.