Okay, be a bit more specific, bud. Did you remove the sight post? ( the little needle thing you use to aim) or the whole sight assembly (that connects to the barrel)
The sight post simply screws in, there is a little springloaded stopper that makes sure its secured in the sight and wont let it move whenever you rotate it.
And the sight assembly, there should be only two pins along the bottom, and grooves in the barrel that help it fit in. if you dont have those two pins... Try and experiment with some pins from a hardware store and clip them off. I had to do that for one of my pistol mags... Works fine.
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Vapir no2