Quote History Quoted:
Does the barrel nut only have one spot for correct orientation for the gas tube alignment. I’ve never installed a barrel nut like that if so. The most shims I’ve used is two but that is on barrels nuts with multiple provisions for alignment.
View Quote
It’s a URX 4. There is no barrel nut. The rail is one piece and threads onto the receiver.
OP, I ended up having to use quite a few of the included shims to get a URX 4 installed on one of my guns. It still works fine with a heavy ass PVS-30 mounted on the handguard and I’ve never had any POI shift issues with the handguard mounted PEQ.
I’d probably just test it out as-is to see if it causes you any problems. You could try a different receiver if you have one available. Or you could use a receiver lapping tool to remove some material from the receiver to see how much you can decrease the amount of needed shims. I wouldn’t go too crazy with that method, though, as it could cause problems elsewhere.
ETA: There were a couple companies who offered machining services on URX 4s in the past where they’d remove material from the rear of the rail until it timed without any shims/gap. Forget who it was, but maybe something to look into as well.