*sigh*
I really like my H&R convertible. Trouble is,,,it's an H&R,,,don't toss the .22lr cylinder,,,,just stick it away somewhere. Who knows,,in 200,,/,,300 years it may fetch your decendant's a downpayment on a house,,, or a loaf of bread ,,,,depending on inflation.
'fore you do that though, at least try some really crappola ammo, like Thunderbolts, that have a lot of waxy lube, and unplated lead bullets. The lands in the H&R are fairly (as The Blues Man said about my Davies Derringer) subtle
. The softer lead may be able to engage the rifling better. Also, you might want to take a small split shot or someting and force it through the chamber mouths of the .22lr cylinder. After you've slugged each cylinder mouth, you can take the split shot you slugged the chambers with and slug the barrel. The shot should come out with rifling marks on it. If it doesn't, the chamber mouths are either extremely dirty or undersized. In either case, you may be able to open up the cahmber mouths with some wet/dry 800 grit sandpaper wrapped around a dowel rod,,or clean em out real well. (I wouldn't do this 'cept as a last resort before the trash bin)
H&R's really weren't made to be long term guns that fired a lot of rounds or precision shooters. They were primarily aimed (no pun intended) at the fur trappers and coon hunters. I have (much to Mrs. RAE's chagrin 'cause they're heavy and plentiful
) a bunch of old early '60's vintage outdoor magazines that have the ads in them for the H&R revolvers. With that in mind, a point blank shot (couple o feet usually) with the .22 lr was standard fare. Tumbling wasn't a factor at that range. The .22 Mag was for coons at a distance, or larger game in a trap. The .32 was supposed to be for yet larger trapped game.