Man hours are dependant on the quality control process also. I agree with those that say a revolver would entail more man hours. But also, from company to company I would imagine the man hours vary for basically the same type of revolver.
If company x decided it wanted to focus more on production numbers, they would produce a certain amount of revolvers in a certain time frame. Company z decides it want more quality in their production, it will slow down the actual manufacture of the revolvers (or any other type of gun) to ensure parts are fitted correctly and meet all specs.
When I worked in a machine shop, we had one contract that would require every piece be spec'd exactly. With another contract, we were allowed a tolerance in the pieces we manufactured.
Even when the machines are set up originally with the exact specification, over time the table gets a little slop in it, the cutting tool may wear a little, etc...
Just a little info that most people do not consider.