[New Shadow 2 with new cuts inside]

Thanks. That’s what I thought but wanted to confirm it. My frame is marked 257 and has the cutouts. 

[New Shadow 2 with new cuts inside]

Ok so I just picked up a S2 last week. Just so I know what to look for, you talking about the cutouts where the trigger spring is?

[powder spillage loading .300blkout]

I would also ground your press.  Helps with static electricity 

[Brands with NO small primers ?]

Winchester doesn't have small primers

[How many rounds can you load per hour]

Never understood the "how fast can you load" thing. I take my time and make sure I make accurate ammunition. No double charges, primer in every case, bullets seated to proper depth....  IMO it's not a race. Been loading for  years and been enjoying every moment of it. 

 

550b no case feeder or bullet feeder

[Case gauge question]

2 questions.

First, Have you tried flipping the round so that the rim goes in first.  Does it fit?  Obviously it will not go in all the way down but it will tell you for sure if the rim is the issue or some other issue that you are not detecting. 

 

Secondly, have you tried your rounds in a different case gauge?  Maybe you have a bad case gauge?  Try a different vender.  Case gauges are typically SAAMI spec and are designed to fit a minimally sizes chamber.

 

on the lube topic, I feel that lube is always a good recommendation when loading. sparingly of course.