For an interesting discussion, go to the Seecamp forum, look at the ammunition topic and scroll down to Mr. Seecamp's thread. The recoil of the weapon slaps the rounds in the magazine forward, moving the bullet further back into the case, thus increasing the pressure and felt recoil and changing the bullet length. With each round fired, this can be cumulative on the rounds left in the mag....last round issues and perceived recoil all affected. The issue discovered there was with the newer WWB production, but apparently occurs with others. Mr. Seecamp's recommendation: For your carry ammo, fired the first 13 rounds of the box, and if they all work, carry the other 7.
