Moly coating is molybdenum disulfide and is not corrosive. But if the moly had some unbonded sulfur, then some later reaction could take place.

That being said, I have never heard reports of someone's barrel corroding from shooting moly bullets. But if it had happened, I think it would be splashed all over the internet.

Therefore I have no concern about shooting moly coated bullets, and I use them from GS Custom, Rhino and Combined Technologies (Nosler).

The advantage of a moly coating on a Rhino compared to an uncoated Swift is that you should get less fouling from the moly coated bullet. Premium bullets often use a relatively soft copper that tends to foul bores and the moly coating can mitigate that effect.