johntheplinker
Master
Great observation! Mine are mostly bolt actions so my crud induced malfunctions are mostly extraction failures caused by a carbon ring in the chamber.I'd say the largest split in this ".22 cleaning" camp is correlated to semi-auto vs. bolt-action firearms.
There's far more fouling in the actions of semi-autos and that tends to induce malfunctions (as mentioned above, generally 400-600 rounds depending on design & tolerances). Bolt-actions deposit most of the fouling in their barrels and it doesn't build up nearly as quickly.
Both types can suffer from leading (where lead is deposited & builds up), depending on the ammo & barrel. At the very least, inspection and monitoring for that issue is important. This often shows up as decreased accuracy and in advanced cases, key-holed targets. Extreme leading can lead to a squib/barrel obstruction.
Personally, I clean mine (all semi-autos) before any extended storage (longer than a couple weeks). Galvanic corrosion is a real thing and I tend to shoot copper plated or jacketed bullets most of the time. This also helps me prevent fouled actions and malfunctions at the range, as I'm generally starting from a zero round count and rarely shoot a full brick at a single session.
Ammo is a big factor, certain brands are notorious for leading (Thunderbolts in particular) while others (Goldens and Federal) produce lots of soot. Since I've gone almost completely to European ammo, I haven't had any leading and crud build up is greatly reduced.