Owen,
You shold try some of the commercial ammo, and compare accuracy. Better yet, try handloading.
The only one I've tried is Fiocchi, as they gave me a couple boxes with the Mak. I didn't test it for accuracy, but it seemed to group well enough offhand.
Just sent for the Wolff spring set for my Mak. You will probably need a new slide spring after a few thousand rounds, as the originals do lose tension. Pay attention to how far the empties are ejected. When the distance you have to chase them increases, it's a sign of a weakening spring. The recoil will also increase when it gets to the point that the frame is being hammered.
Have fun, it's a great little gun!
Bill