I'm as sure as I can be on the 4.7 grains. I knew I would be getting up there in pressure so I was quite careful. I adjusted the micrometer charge disk on my Lee Pro Auto Disk. I got it to where I was pretty certain it was throwing right at a 4.7 grain charge. Every charge I weighed was 4.7 grains on my Frankford Arsenal digital scale. I verified the weight with my Dillon balance beam scale. Then I threw ten charges and weighed them on the digital. 47.3 grains. Checked it with the balance beam and it was the same. Did that a couple times. I threw ten charges with shaking the powder measure as much as I could to ensure the powder didn't have a way of compacting to get a heavier charge. I got 47.4 grains and 47.6 grains. I was really shaking it and trying to get the powder to compact. My press doesn't shake the powder measure nearly as much as that when I use it. So, I'm fairly certain I was really close to 4.7 grains. Most the charges could have been was 4.76 grains.
The cases were range brass. Not sure how many times they were loaded. The case that split was one of my own once fired cases.
I looked at the chamber and couldn't see anything. There is a little bit of fouling where the case split, but I got most of it removed. You can just see a faint fouling line that matches the shape of the split. No gouges, scratches, etc in the chamber.