I just got the .25 cal Gauntlet last week. After getting a pump and several different pellets, I was able to bench it. The regulator was not at 1900psi as stated, and the 26 grain Poly Mags were flying at 825 fps +/-. Still a significant power house, and I can shim the regulator to get the power up.
Unfortunately, the groups sucked at 50. Around 1.5" with JSBs, H&Ns and Poly Mags. I cleaned the barrel for a long time prior to shooting, and what I thought was factory gook in the barrel is apparently rust, After shooting, I ran 15 or so more patches through it, and they were still coming out brown. I pushed some pellets through the barrel, and the rifling marks appeared ridged and uneven. The bore looks crappy to the eye, and may be pitted in spots. I'm going to bore scope it at my buddy's later today. If what I suspect is correct - it's getting returned. However, I will be getting another one, because they're a package that's hard to beat.