I think the only "leading" / cylinder issues
have turned up under these conditions:
1. Dirty--really dirty guns.
2. Some of us shooting reload recipes and experiencing issues with the lube on our particular-brand bullets.
3. The occasional hardware problem--possibly timing, etc.
AFAICT, the 3xx-series (scandium 357 j-frame, various cylinder metals) are typically assembled better, and to tighter specs, than the airweight / x4x-series guns.
Because I shoot reloads, I routinely remove the cylinder and clean it thoroughly after my range trips. I keep a clean gun for carry--period; I always clean after a range trip--and I carry either the GDSB 38+P 135-gr. round, the Rem 3812 (LSWC-HP), or the BB20 (38+P+ 158-gr. lead). With a clean gun, there are no issues with any of these rounds, even after 50 rounds. Overall, then, I think "problems" with lead bullets is largely a non-issue.
Jim H.