firing pin

Question
what are the benefits of floating firing pin?

Answer
There are no real benefits, except that it is easier and cheaper (by pennies, which may be an issue to a company that is producing hundreds of thousands of guns) to manufacture.

You'll generally find floating firing pins on military rifles, which will rely on the hard primers of military ammunition to avoid "slam firing" (the phenomenon of the round being fired by the inertia of the firing pin hitting the primer upon the closer of the bolt on a semi or fully automatic rifle or carbine).

Some rifles, such as the Russian SKS, were originally designed with a firing pin return spring that kept the gun from slam firing upon closure. This feature was deleted somewhere around 1951 in the Chinese manufactured guns, with the predictable results that slam firing sometime occurs with them.

In some cases after-market companies have designed and sell re-engineered firing pins and/or bolt carriers (depending on the design) that incorporate a firing pin return spring for civilian markets, as commercially produced ammunition tends to have softer primers and are more susceptible to the phenomenon of slam firing.