I own and shoot virtually all of the semi-autos from 1938 forward. While it's difficult to compare them side by side as each has its own personality and foibles, I'd say that the VZ52 and the 52/57 are both excellent shooters. They are very accurate to, say, 150 yards and are very pleasent to shoot. They do eject to the left, however, which is something a lot of guys don't know initially. That's a surprise!
The 52/57 makes that 7.62 x 39 round really sing, too. It's a step above the SKS imho, and feels good in your hands and shoulder and the action is very pleasent to handle. It's a sleek looking rifle, too, reminding me of a shark, actually.
No one makes 7.62 x 45 ammo anymore. The last of what was available was imported several years ago and got bought up at about .10 a round while it lasted. Now that it's gone, and no more has been imported or discovered, that caliber is pretty much dead.
A couple of years back, we begged some of the ammo makers to put out 500,000 pieces of brass for this caliber based on a pre-sale deposits from collectors like myself. None of them were interested, however, probably because the numbers were just too low. I'd be willing to pay .35 -.50 a piece for brass, however, and I'd bet that others would too. So, there was money to be made but no one would even give us the time of day.
As the poster above has indicated, you can create more using 220 swift brass but I don't reload so I'm going to rely on my stash I've put up for quite a few years. I do, however, also own some original brass-cased 7.62 x 45 ammo. It's berdan primed but it is brass and would be reloadable. I also have some Buffalo Arms ammo I purchased that is boxer primed and was made from 220 swift cases. IT cost me $1 shot, however, but will ensure that I'll have ammo for my rifle for as long as I own it.
Anyone who collects semi-auto rifles should definately have one of each of these rifles in their collections. Because of the scarcity of ammo, the 52 is really and inexpensive rifle to buy today. The 52/57, however, has really climbed in price over the years as it's much rarer than the 52.
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