I've got a question here. I've got a Model 17-5, 6" barrel. After cleaning, when loading, all six rounds drop in effortlessly, and eject easily. After loading four or five times, I notice it is more difficult to eject.
As a test, yesterday, I ran a brush through each chamber, and the gun was good as new, for a while.
I cleaned it last night, ran the brush, then patches through the cylinder, and earlier this morning I ran a "foam pad" with a few drops of Hoppe's oil on it, then took a photo. To me, visibly, it looks like the chamber has one diameter for the length of the case, and perhaps has a tighter diameter for the rest of the cylinder - but this might just be an optical illusion?
At any rate, if when the gun is clean, new rounds drop in with no effort, I don't think I would want to use a reamer on my cylinder. It sounds to me more like a dirt/debris problem, which is instantly fixed by running a wire brush through each chamber, bringing things back to the way they were after cleaning.
This has happened with CCI ammo in the past, and with Eley bulk 22 ammo yesterday - but again, I had no problems shooting, just running a brush through the chambers if things started to feel "tight" again.
I'll post a photo of the back of the cylinder after cleaning.