"tadpole tail" primer hits

[H&R088]

I recently took a new pistol to the range and after inspecting the fired brass I noticed the primers all had an obvious tadpole tail hit. Does anyone know what is causing this, and is it something I should return the pistol to the dealer for?

[Hunter]

Check this link it may help.
http://forum.m1911.org/showthread.php?t=15669&highlight=tadpole

[H&R088]

Thanks for the reply. I noticed that in one of the posts they said that Glock .40's do this . The gun I was shooting was a CZ75b in .40 s&w.