Poor fitment! :( - Faxon Firearms Match Series Glock 43 Threaded Barrel

I have three of the G43x Mos and two G43's, for whatever reason there was a ton of friction when closing the slide on all three 43X's. It was so bad that there's no way any of them would have properly cycled. However on my two 43's the barrel worked perfectly fine with no hang ups. It doesn't make sense because the 43x and 43 have the same barrel. I don't know why there was a problem, but there certainly was, bizarre as it is. I'm only giving it 2 stars instead of 1 because it did work perfectly fine in the 43.