I have a top-break, single-action, 9-shot H&R Sportsman 199 that works very slick, with no sticking and easy ejection. I did get some el-cheapo ammo once that had a heavy waxy type residue on it that made chambering tough, but this was the exception and not the norm. Good old Remmy's, Winny's, Federals and CCI's always worked well.
The dimensions of the .22LR were standardized a long time ago. A .22LR from the 40's is the same size as today. If anything, the chambers were probably a bit looser in the old days than they are today.
When was the last time yours was fired?
Is there any surface rust or crud built up in the chambers?
Are all the chambers just as tight, or just a few?
I'd give it a good cleaning with a few wet patches, then a stiff spiral wound bronze wire brush, and then a few dry patches and see if this makes a difference.