OP,
Occasionally barrels will turn up on Ebay or Gunbroker, but at rather high prices. It appears that the conversion is not always as simple as a barrel swap. I found this some time ago when I was considering the same swap....
? 9x19 Federal Barrel Feeding Problems - as quoted from the Federal conversion instruction sheet
Some CZ-52 pistols converted to 9mm NATO will show feeding problems. This is primarily caused by the fact that the 9mm NATO round is shorter in length than the 7.62x25 Tokarev round. There are 2 areas of concern: magazine feed lips and the way the extractor pushes the live round into the chamber.
Surprisingly the extractor is the main cause of feeding problems. The lower 1/2 of the front end of the extractor actually contacts the round, pushing it into the chamber. By smoothing and rounding the angled surface on the lower 1/2 only, the extractor hook will not disrupt the movement of the round as it jumps around the rim of the cartridge being chambered. To remove the extractor, use a 1/16" punch to drive the pivot pin through the slide. This will release both the extractor and its spring. When you reinstall the extractor and its pin and spring, check to see if there is free movement by pushing on the rear end against the spring pressure.
Examine the feed lips of the magazine. Look for jagged or bent edges. The metal at the lips is heat treated, so you may not be able to bend them back without weakening them. It may be necessary to have a welder add metal to the leading edges of the feed lips. Excess metal would be removed by a Dremel tool.
FWIW
YMMV
