Around 1990 I bought a North American Arms .22 mini revolver.
It was a beauty and fired just fine but all the bullets keyholed. When I got ready to clean it, I realized the rifling did not quite go all the way to the muzzle. Maybe the last 1/10 inch was not rifled.
My dealer returned it to them and they fixed it with no problem but I can’t believe it got out of the factory like that.