Thanks Guys. I think I'll be picking them up and giving it a shot (pun intended). If however, they don't feel right, y'all that like them keep your eyes open cause I'll probably post them on here to sale.
I have had my 27 for over five years and until the other day, second clip after adding pierce +1 extention, it jammed. The last round jammed the slide open as the cartridge butted (and was stuck) at the base of the barrel oppening. Once I cleared the Jam, i replaced the last round with another and it did it again. So I am now kind of cautious. It didn't jam the rest of the day, about 100 rounds later, but I definately stuck with the original unmodified clip.
Hmm, in my situation where a jammed weapon can be the difference between life and death, I guess 1 round doesn't really make that big of a deal. As my Glock stands now, I now it's going bang when I pull the trigger. I suppose 40 rounds will hopefully be enough to handle whatever I may come across.