Like I said, I've been traveling there for over 25 years, my last trip was a week ago. I've been visiting China in the roles of a scholar, analyst and businessman over the decades. I'm a conservative and there's plenty for me to hate about the country, but China is nowhere near a "powderkeg" of revolution or collapse..
Unless you understand the history, politics, military and economy of China (or any nation), what you only read from a single source or learn from a small group of similar-minded people isn't going to give you enough data to understand a nation as complicated as China. Those who want to use words like "revolution" need to first answer the question "why"?
Look at ourselves, aside from a very very small % of Americans that want to actively overthrow our Govt. (typically nutjobs) -how many of us serve and protect our nation, even if we don't like 100% of what's happening here?
China is growing in wealth, power, military and political influence. The average Chinese is immensely proud of their nation and feel their govt. is taking the right steps in taking it's place as a global power. This doesn't mean that they won't "bitch and moan" about local issues, the economy, their jobs, rising costs, corrupt politicians, etc... hey, doesn't that sound like us Americans?
What is reported as "unrest" is typically focused towards local govt. incompetence or corruption, not a call to arms to overthrow the Govt. This "unrest" also typically includes a call for regional or national Govt. to intervene. (historically, this is the pattern of how Chinese peasantry acted in order to get the attention of the Emperor)
BTW, 40 million firearms, mostly from 1910-1945 era, would only arm 0.03% of the population. This doesn't take into account the lack of ammunition plus general poor condition of the firearms due to harsh environmental conditions.