You could say the same thing about any double rifle. They. too, have a "very fine" fit between barrels and action, so I suppose they shouldn't be taken into a situation where they could be exposed to dirt and refuse to close.

Seriously, you make an interesting point, but I don't anticipate pulling out a scope and trying to mount it in the midst of a stalk. Range is not the consideration for using a scope. I am perfectly capable of hitting a small target at 300 yards with iron sights. Light conditions would be the determining factor, and that can be anticipated well before the fact, and the change in sighting equipment made at leisure, under controlled circumstances.

Incidentally, if the threat of contamination bothers you, never think of using claw mounts, which have the additional disadvantage of moving parts enclosed in the bases to get clogged up with dirt and grit.