Neophyte, Enlarging the chamber just makes things worse. The more the brass expands, the harder it will be to extract and you could even risk case ruptures. I have a S&W Mod 18 with chambers so tight, I have to literally force the 22s in place, even when the cylinder is sparkling clean. After they are fired, the spent cases extract with ease. Some of my Ruger Single-Sixes are like yours and also eject a little hard. As long as I can push the case out with the ejector rod, I'm not going to make any modifications.
You have one of two conditions ... both being quite common in Ruger SAs. First, do a close inspection of the chambers and look for machine marks that almost resemble threads. When a round is fired, the case swells up and literally locks into the chamber's "threads". If you see "threads" try some 400 grit wet or dry sandpaper rolled up on a rod. Instead of a rotary motion, go in and out like ... well you know. This will remove some of the "tread effect" without enlarging the chamber too much and will help extraction. Do all 6 holes and make them as uniform as possible but don't over do it.
Second ... The wall of a 22 case should be straight .. no taper at all. If the chamber is also "straight" and smooth, the cases will extract just fine. The following condition is not repairable without installing a new cylinder (if bad enough). It is a condition caused by the reamers being worn when the chamber was made. If the chamber has a reverse taper where the chamber diameter is larger at the case mouth than in the middle, there's no way a case will eject easily. When a round is fired, the mouth of the case is allowed to expand more than the middle of the case, thus hard extraction. If you reamed the chambers to make them straight, they would end up being way oversized. A careful inspection of your spent brass will confirm this condition. Next time you go to the range, save several of the spent cases that ejected hard. Use a precision caliper to measure the OD of the cases. They should be the same diameter from rim to mouth. If the mouth is slightly larger than the body, you found the problem (even if the mouth is only .0005" larger).
Another issue is oil .... chambers should be bone dry ... no oil at all. Oil picks up powder residue and actually increases extraction friction. If you previously oiled your chambers after cleaning, try shooting the gun again starting with clean dry chambers.
I guarantee ... one of the above is the culprit.