Quoted:
Does anyone know about Black Hole Weaponry's 6x45mm poly rifled barrels and their quality??
I bought one in 18" with a rifle length gas system, 1-9 twist. It looked good but I did have some minor issues.
- Large burr in the bore at the gas port location. I knocked some of it down with a bore brush.
- Barrel threads out of spec. I could not screw on a flash hider by hand and had a lot of resistance with a wrench. I decided to buy a die to clean up the treads.
- Gas port not quite large enough. I had major function issues with several different loads on a rifle lower. Gas port diameter as delivered was .102". I opened the port to .109" (my next larger drill size) and now it functions fine.
That being said overall I am satified and I would buy another.
If you build one I would suggest the RCBS AR series dies. I got mine from Midway for less than $40 and they work great.