I haven't personally checked mine, but according to Richard Hobbs, the M38 is standard twist. Which,BTW, makes sense because the barrel is really too short for a gain twist rifling.
The kinda accurate one actually has a fairly decent bore, no pits and sharp rifling. The other two not so much! Your experience with the 92 and Trapdoor is not unusual, but a lttle atrange when you consider that they were both made for and used exclusively with lead bullets, back in the day.