Wolf Ammo
I've heard a lot of negatives about wolf ammo over the past few months. Most of these comments revolve around the extremely dirty powder they use, causing excessive fouling of the weapon and everything around it (including you if the wind is in your face) and the fact that they use a type of varnish to seal the round which, after your weapon heats up to the varnish's melting point, causes emptied cases to stick in the chamber and further fouls the weapon.
Bottom line is that whatever you save in cost, you will pay in effort getting your weapon clean. Avoid the wolf ammo.