mainspring balancing act!

[velodog455~]

G.T.:
I have discovered that Winchester is making their 9mm white box ammo in two locations now, one being the traditional U.S. made WWB that everyone is familiar with, and another WWB variant made in Bosnia. I most often see the Bosnian ammo at Academy Sports.

The two different ammo types chronograph differently, for me at least. The Bosnian stuff chronographs a bit higher and it subjectively feels like it has a bit more recoil.

The country of origin in tiny font is on both the U.S. and Bosnian boxes (which look pretty much identical) but is often covered by UPC or SKU labels applied by the ammo sellers. I'm just wondering whether or not you might have been using both U.S. and Bosnian ammo in your testing. I can see where it could cause excessive head scratching if you were using different ammo types without knowing it.

Of course, if you already know this then disregard as you see fit.
-Bob