Has anyone shot one of these?
SIngle action pistol, single stack mag, classic design, typical for the era when was designed.
This was standard issue yugo army pistol, till late 1980ies.
Later versions of this pistol were made in 7.62x25 and 9x19.
The difference between Yugo M57, 7.62 from Russian m33 TT is longer grip in yugo version, to accommodate longer single stack magazine, which holds 9 rounds, (russian holds 8 rounds )
the other significant difference is recoil spring guide rod.
Russian version is one part piece.
Yugo version is two parts, hinged at half length, with recoil spring permanently fixed.
Military version of M57 on left side of slide has stamp: 7.62 TT mm, and Yugo coat of arms on top of the slide.
(most notable marks)
Civilian version will have stamp Zastava Arms (or import company), on left side of the slide, no coat of arms on top.
Those are basic differences. (there are several more)
In addition to above, civilian export version (for US market) will have installed some type of safety.
Military version does not have safety, except half cock, position of hammer.
This is safety flaw, as it was noted on some occasions, that when falling or hitting hard, from half cock, an accidental discharge could happen.
Fun to shoot, very loud bang, high velocity for pistol, and high penetration, accuracy not perfect nor impresive, but will hit the target (black circle at 25 meters, at ISSF pistol bulls eye target), or coke can at 10 meters.
Another "feature" of this pistol, the trigger pull is very hard, in original military version.
To remove the barrel, when field strip, front bushing must be removed.
It has more then generous tolerances.
(I always suspected, that making new tight - fitting bushing, and replacing original with good gunsmith, will significantly improve accuracy, but never tried to do it)
Back market muzzle brake, fits in the place of bushing. then recoil is very mild, but accuracy the same.
Below photo, I fitted more ergonomic grips, that include rubber beaver tail. (now it looks like 1911
I also took it to gunsmith, to lighten the trigger pull.
I have seen commercial ammo by PPU and Sellier Bellot, FMJ and JHP.
Other factories, never.
Below is my pistol, trigger pull lightened, added ergonomic grips, and not shown on the photo muzzle break is available. Never had fail to fire, or fail to extract.
My educated guess, your photo shows, refitted mil surp pistol, with later istalled safety and exported to US. I cannot see the coat of arms on top, but I can see letters on the grip SFRJ, this was for military issued guns, civilian versions had Zastava logo, on pistol grip.