[November]

I'm considering this rifle and was wondering what kind of gas system it uses. Is it like the AR-15 which dumps the spent gases right into the action of the rifle during operation, or is it like the AK or Mini-14 or something else which keeps the gas pretty much away from the rifle's action?

 

[Flyer]

Okay.
First: The AR's action is the BEST AVAILABLE ANYWHERE.
It doesn't MATTER whether gases are vented into the mechanism; since the correct powder has been used since the early seventies this isn't a problem, and it contributes IMMEASURABLY to lighter weight and accuracy.
Now... the SU's action is akin to the action of an AR-180, but uses only one "action" rod instead of two to cycle the action... in other words, it's basically an AK inspired gas rod which operates an AR style bolt and bolt carrier assembly.
In the case of the Mini 14/M-14/M-1 Garand, they use a massive BLOCK which cycles back and forth. This block is effectively given a "kick" by a small rod which protrudes against the block and is driven by the gas pressure. It depends on the WEIGHT of this block to cycle the action.
So, no... the SU doesn't vent the gas into the action.
Flyer