Food for the Swiss Babies

[TwoRivers]

TwoRivers: The MG42 and STGW44 did have an influence on the overall design of the 57. Whether or not you agree is a moot point. The literature on the STGW 57 describes it as a delayed blowback. Rudolf Amsler admited to being influenced by these designs.
The cartirdge does float on the gas cylinder formed by the fluting to aid extraction, and yes the bolt is locked at the point of firing. However from what I know this is quite different to other roller locked mechanisms.

In any case we can sit and argue about designs, but I think I am going to the range to shoot it instead.

"...to shoot instead." Much the better option. The StGw44 influenced the overall design, not the way it operates. And we were after all discussing the operating principle.
English-language literature may describe it as a "delayed blowback". But that term was coined long before, and describes an unlocked breech system where the rearward movement of the bolt is retarded/slowed down through mechanical means. Examples would be the Remington M51 pistol, Savage pistol, Thompson (not all) SMG, Hungarian M43 SMG, Dominican Republic "San Cristobal" carbine, Pedersen rifle, Schwarzlose MG. These are all delayed blowback, unlocked at the moment of firing.
The roller locked designs, StGw45, Cetme, H&K, STG57 are, by default, included in the "delayed blowback" category by English-language authors. But they are locked at the instant of discharge. So we are getting into semantics, and blurring definitions. And yes, you can use rollers to lock, but use short recoil, or a gas piston to unlock. A variation of "locking flap" design.
Yes, the case floats on the gas allowed to flow back by means of the grooves, and so can not grip the chamber to the point of being torn apart during extraction. Did anyone dispute that?
Enjoy your day at the range. Cheers.

[xl_target]

For those of you who are interested in the K31, here is a source for Swiss K31's, K11"s and M1896/11's.
Also the K98 Mauser and the round receiver Mosin Nagant m91/30 at reasonable prices. Granted, they probably won't be in the excellent shape that MOA's baby is in but still these are priced right.
http://www.wideners.com/itemview.cfm?dir=700|701|1029

[MoA]

Ordered another couple of cases of ammo, and a W+F diaopter that costs as much as the rifle for all practical purposes. Pics when they arrive.

[TwoRivers]

MOA: Just out of curiosity, what do you have to fork out for the ammo? Fairly expensive over here.

[MoA]

Its fairly expensive here as well. Its between the equivalent of $280 and 325 a case. Depends on the quantity purchased as well. The civillian packaged cartons of 50 tend to cost more ($41), as do buying individual bricks.

Partizan 7.5 is about $18 per box. The brass though is boxer primed and reloadable. I plan to try some reloads this weekend but doubt if it will out perform the GP-11 ammo.

[TwoRivers]

We pay around $40 or better for the sixty-round pack at discount. I have been able to match, but not better the accuracy of the GP11 with handloads in either of my K31s. But you may find the magic combination.

[MoA]

Would love your recipie.