This applies to the Gen2 P-Mags that you may have just received:

http://www.magpul.com/catalog/index....roducts_id=271

"It has come to the attention of Magpul Industries Corp that a number of users have experienced feeding problems with their PMAGs™ due to unusually tight magazine bodies. The primary symptom is sluggish follower response, or snagging when loaded with more than 20 rounds. These issues are a result of dimensional changes occurring after the PMAG™ left the Magpul factory, and only affect the PMAG™ body. Other PMAG™ components such as the follower, lock plate, floor plate, and impact cover are unaffected.

Improvements in the manufacturing process have resolved this issue on all PMAGs™ dated 7/07 and later...."