I'll kick this again and add some information from a friend.
There is the issue about when the magazine opens and shuts to allow a cartridge onto the elevator.
There can be an issue with when the locking pins engage the bolt and lock it in battery.
And we wondered about this, but if the elevator is going up while the bolt is going forward, the length of the cartridge may matter. That is, a longer cartridge may arrive at the back of the barrel sooner than intended by the designer and a shorter round would arrive later. In either case, they might miss the hole - especially common pistol cartridges as opposed to bottle neck cartridges - because there is less to aim at. This would be more of a problem if the elevator rotates up as opposed to being raised level.
I will further guess that where everything is at any given part of the cycle depends, directly or indirectly on the size and shape of cam surfaces of the lever or what they engage. Exactly what you do to these surfaces depends on the problem and which way you want things to move.
Does this make sense to anyone?
The magazine opening and shutting is the cartridge stop. The adjustment of this is going to have the most bearing on the question of using 38 spls in a 92 action.
The locking bolts won't affect the cartridge length.
The carrier snaps up on the forward stroke of the lever, it's in place before the bolt starts forward. It can have a bearing on the maximun length of the cartridge, and can be modifed to allow a slightly longer cartidge, but not by much. If the cartridge stop is set up right, I don't think the carrier should need to be fooled with to let a slightly shorter cartridge to work. At the point when the cartridge stop should be working, the cartridge is held slightly forward by the lever, (thats what keeps the cartridges at the right place by the loading gate so more rounds can be put in, and let the cartrige stop do its work) and is coming backwards as the bolt is opening, to stop against the stop on the carrier.
The lever is pinned into the bolt. It shouldn't have any bearing on adjusting the gun to use 38 or 44 spls as opposed to magnum length rounds. The only thing it "cams" is the firing pin backwards as the bolt is initially opened, and it pulls the locking bolts down on its first movement. Nothing to do with feeding different length rounds really.