My Gauntlet2 has never had trouble firing, it had trouble hitting what you fired at.
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I sent it back for warranty and they shot test group of about 3/4" at 20 meters, and said that was what was expected from this gun. It wasn't what I was expecting. I didn't know when I bought it that my old 72 Sheridan Bluestreak, was conciderably more accurate then this beast.
I bought the gun watching Hajimoto's videos expecting his kind of accuracy. As it turned out Hajimoto responded to my thread and educated me on the rifles issue, along with a picture.
If you have a hard closing bolt, the pelets are being damaged in the chamber, by the sharp edge of the rifling, because there's no transition chamfer. Then lead chips from the damaged pellets foul the rifling ruining accuracy.
View attachment 542377 This is a common issue with some of these that Umerex decided not to warranty and let us live with.