I measured the barrel this morning with calipers and I find no unevenness that suggests anything terrible happened to the barrel itself. I don't think #3 really can be an issue here or I would see some swelling or at least the calipers would.

Some folks looking at the bolt think that it lifted straight up. I tend to agree. it was laying beside me while I did my body part inventory immediately after the blast. Two large objects punched big holes in the metal canopy as well. The blast went mostly up, not back, my face not withstanding.

The tire and string method is always a good idea at first, but I had already shot over 100 of this specific load. The first 100 fireformed the brass. It was the 119th shot that did the dirty work. So, unless you are going to do the tire and string forever, well....

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BrentD, (Professor - just for Stan)

[Linked Image from i.imgur.com]