Just thought I'd throw this in here for anyone still looking through...

I had purchased 300 rounds (total) of Remington UMC, Federal Champion, and WWB. Was able to burn through about 215-220 rounds and, through all that were fired, still no issues firing or feeding. As far as the springs being removed from the trigger assembly, not a single issue there either.

As a side note...everyone, who took a look at the Sigma, was quite pleased with it. Several people, upon finishing off a mag, said they would have to take a serious look into getting one. The only people who showed no interest or rolled their eyes were Glock owners. But hey, to each their own.