I have recently started casting with pure line-o-type. It appears that a good rule is that for pistols, reclaimed ,fluxed and importantly* averaged *hard pistol lead are OK at the "usual" velocities. Some of the semi-jacketed types are very soft lead and can affect the alloy mix adversely.
But for velocities over 1,500FPS a gas-check and plenty of lube is needed -I have been strongly advised.
I load commercial lead projectiles(SWC and WC mainly) in my pistols- as it is easily available and cheap. There is always some leading in the cylinders and forcing cone and barrel of my M14 S&W(750FPS), none on the 7.62mm Nagant (650FPS)and very little at the muzzle of my CZ75 at about 1,000FPS.
I can't work that one out!
But for the 30/30(7.62 diam) rifle I load with 10gn of 4754SR Du Pont with Winch cases and WLR primers with home-cast 150 LEE projectiles, lubes with LEE ALOX mixture all over, to around 1,450FPS without a gas check (hell they are 4c each here!) and have had no problems yet as regards leading. Nice load for target too, nio problem with magazine load RF either.
But I agree -it must depend upon the smoothness of your bore and importantly the quality of the lead.
I was told .32s are hell to mould( fiddley - too light), but I may try .38SPL SWCs in reclaimed pistol lead from our Club mound, as I feel the leading I am experiencing could be due to a soft lead mix in the commercial bullets I am presently using.
[ Though I never questioned it before I started lead melting/pouring!!! It was an integral part of pistol shooting I thought.]