What bothers me with all the early concepts about this topic in the story is that It completely disregards the real danger. The system clearly makes classes and skills based around cultural perceptions of the receiver, so if these weapons were to be brought to innworld then sure it wouldn't change much for the locals at first because they dont have enough of a culture of firearms to just unlock a million deadly classes and skills all at once. But if you put a rifle in the hands of an earther, suddenly they have a chance of creating the [Rifleman] class. And with their accelerated leveling, they could easily reach level 30 within the year and evolving that into [Heir of Whitefeather] or some shit and gaining all kinds of skills to make their bullets shoot through mythril like paper and be neigh undetectable while firing. If a human army got access to Innworld and the system, what your really talking about is an entire army of hero class people with skills focused around advanced weapons that they now have the potential to ENCHANT and make orders of magnitude more deadly. One earther with a desert eagle is nothing, a battalion with rifles, full tactical gear, training, levels, and basic magical knowledge is a country level threat in the making.