PROBLEM FIXED!!How to polish a barrel “mouth”? Issues feeding rounds.

[ShooterMcGaven]

I bought a threaded barrel for my IWI UZI PRO. It’s not a stock IWI barrel, it’s a Pike Arms barrel. 

It does not want to feed rounds, it just jams up. The threaded barrel is not polished at all and seems to have a different “mouth” to it where the rounds feed in. The stock, non threaded IWI barrel is nice and polished. You can actually see brass marks where the rounds were hitting the barrel and jamming in the pic below  

I’m curious on tips for polishing the threaded barrel and removing the black finish on the “mouth” and down into the barrel. 
 

Thanks!

Edited February 26, 2023 by ShooterMcGaven

[scatman]

I bought an aftermarket G19 barrel that had a too much of an angled feed ramp, what you're describing as the "mouth",  had to file it down some to solve the issue. Polishing your barrel may help, but I would compare feed ramps more closely, perhaps use a caliber to measure thickness of the ramps, the aftermarket could have a thicker feed ramp that is too tight in tolerance for your model.

[drdirtnap]

Cratex or rubber polishing bits.  Get them on Amazon.