Above all expectations
I ordered the spartan piston version about a year ago and I was a bit worried about this rifle's tolerance toward different cartridges, since the piston was not exactly adjustable. After putting over 100 rounds of different brands and weight through it I had zero failures. It is easier to clean as well. The manufacturer's name was not well known, but their customer service was superb. Very impressed so far.
Reviewed by: YL from CO on 1/3/2014