From what I have experienced over the last 40 years, S & W .22 chambers always seem to run a bit tight. I notice that certain ammo works better than others. For instance...... Federal .22's are the tightest, Winchester's are not as tight, and Remington's are the least tight of all. I personally do not like the quality of the Remington .22's (a lot of FTF) so I have decided to use Winchester Wildcats for most of my informal plinking. That said, I have had trouble finding them over the past year or so, so I did actually purchase a few bricks of the Federal Champion .22 ammo. Now when I shoot them I have a nylon brush at the ready that I use to swab out the chambers every 50 rounds or so. A little more effort is involved, but not a big deal. On the plus side, I do think that the Federal .22's are the best quality overall and seem very accurate.

I also have a few Colt .22 revolvers and the chambers on those are quite loose compared to the Smiths. I have never been able to get a straight answer from Smith regarding this matter, so it is what it is.

I would NOT ream out the chambers, just polish them with caution and use a Nylon brush once in a while. Works well for me.

Regards,
chief38