I've been waiting for a QO330M200PRB since last September, I check every month and they tell me another month. I find it hard to believe they can't narrow it down better than that. I was told on another project that required a 320A milbank meter socket, the lead time was like 70 weeks, over a year! So if I were you I'd start looking around. I got lucky, my supplier had ordered a bunch prior to that so I got mine in decent time, lots of guys not so lucky.
I also installed a SqD DU322 disconnect today, one of the lugs I tightened it down and the lug twisted, I said that's odd. Took the lug screw out and the screw holding the lug down was a Phillips and had been stripped from the factory. Luckily, I only need 2 of the 3 poles so I got by. But what the heck man why does it seem like quality control is what everyone is skimping on? This is the wrong industry to be doing that in.