Another product addressing the exact same issues, as good or better than the Wolf is the SAW Sales "green" extractor spring used with the black insert. This spring was developed to solve the extraction problems for short barreled, full auto carbines in hard, life or death use - it is more than equal to any challenge a semi-auto can throw at it.
SAW - Specialized Armament Warehouse - www.sawlesales.com - is Colt's full auto/LE/Military civilian distributor. Ken Elmore, the owner, teaches Colt Law Enforcement Armorer Schools - and you will learn more about ARs from him than anybody - except maybe Tweak!
The "Green" extractor spring and his "Red" Magazine springs were developed to maximize full (and semi) AR reliability based on a LOT of knowledge developed working with Colt, the US military and police armorer communities.
Some don't like Ken for his somewhat more stringent ordering/restock policies and his "No BS" attitude, but his stuff is first rate. And Trina, his wife, is great to deal with.
Either product is an improvement from the stock extractor springs, particularly important on 16" and shorter guns that have more violent extraction.
Warmly, Col. Colt