Which really isn’t a helpful attitude on the dealer’s part, but it could be understandable. The dealer might hate Core15 too, but have some kind of contract to have to sell their stuff until a certain date, or an inventory they want to get their investment back on. And if they badmouth Core15 to their customers, now Core15 is on their back... no win from their point of view.
I’d say see if you can speak with the manager and find out if that’s the case with Core15 guns. The fact that a new gun would not properly seat the ammo, or whatever a gun is expected to do in operation, is awful suspicious to me. That’s shoddy. Guns are supposed to shoot and because shooting well is a safety issue in more ways than one, it seems a production problem to me.
The chambering issue was an easy fix. That it won’t seat some magpul magazines speaks to a production issue. The magazines won’t latch and fall out.
Like I said, its the only gun I regret having purchased. That shootstraight wont stand behind their recommendations speaks to the store.
FWIW they’ve had a number of accidental shootings at their indoor ranges. Besides these gun rental suicides. Possibly because they don’t supervise very well and the lanes are really narrow but thats just speculation on my part.