That is the point...
The metallurgy is suspect because of the nature of the failures I have observed. The failed parts do not seem to be related to anything other than accelerated electrolysis... dielectric corrosion. The parts in the trigger safety link are not the same as the rest, nor are they equally noble.
Once again, it is "galvanic corrosion", or "dissimilar metals corrosion", not "dielectric corrosion".
As I said, if you have the right conditions - good electrical contact between dissimilar metals, bathed in an electrolyte, you can get galvanic corrosion. In other words, if you have your trigger mechanism more or less bathed in seawater, and leave it like that, then it is a possibility. But equally so for other designs too, such as Howa and Remington (and others too). After all, each of those has parts in the trigger group made of different metals - bolts and springs and clips of blackened steel, for example. And even without galvanic corrosion, leaving your typical hunting rifle's internals bathed in seawater is not likely to be a good idea, as neither plain carbon steel, CrMo nor 416 is much good at resisting seawater. I'm not surprised, if those are the conditions under which you hunt, that you are seeing rusting, especially of the parts which are out of sight, and probably not so readily cleaned and dried. I doubt that it is a common service condition for a typical hunting rifle though.
One other point with regard to your galvanic corrosion theory - and I'm not discounting it out of hand mind you - is that if you did have the necessary conditions, including a rifle whose internals were more or less bathed in seawater and left like that, then what about the other dissimilar metal? The aluminium bottom metal, given that aluminium is a good deal less "noble" than any of the other materials, could be expected to become the anode, and suffer corrosion in preference to the other parts, thereby protecting them much like the sacrificial anode on an outboard boat motor.
Anyway, an interesting discussion, but unless you want to leave your rifle more or less bathed in salt water I can't see that galvanic corrosion of components of the trigger group is going to be much of an issue.
