[Flyer]

I'm looking forwards to your range report about this pistol!
Unlike others of it's type, it's not a "locked-breech" pistol at all, but a delayed blowback, accomplished by machined grooves in the chamber that the case expands into 'tlll the pressure comes down.
I've always mean to get a Daewoo, but they're pretty hard to find here.
They look very nice!
Flyer

 

[Flyer]

From the most recent "Jane's" pistol reference:

The DP51 is a semi-automatic pistol in 9mm Parabellum caliber, operating on an unusual delayed blowback system. The interior of the chamber has a number of shallow annular grooves: on firing, the cartidge brass expands, under the high chamber pressure, into these grooves and thus prevents the case from being extracted and the breech from being opened. After the bullet leaves the barrel the pressure drops, the brass contracts to it's normal dimensions, and the breech can then open. Designed for police and military use, the double action trigger is better than most, providing a very even trigger pull.

Flyer

 

[Flyer]

Of course, that's not to say that they might not have re-designed the pistol for import requirements or something like that...
Flyer

 

[Flyer]

Yep, and so do the HK series Combat Rifles and Cetme .308 rifles with roller-locking mechanisms... makes the brass almost impossible to reload.
Flyer