Did a little more "sleuthing" this morning.
Since it may be a very long time before I get my headspace gauges made, I decided to go to my "fall back" and make my own improvised no-go gauge. It ain't pretty, by works.
True to specs, I got the bolt to close up to just under 1.720; and at or above it would not. Nonetheless, .01 slack in headspace in an AR is "enormous" compared to what I've worked with before in any other AR cartridge--most of the trim-to case lengths I've seen for the 350L are around 1.701
Notice the odd scoring on the brass on removal from chamber. This was virgin starline brass on a freshly cleaned chamber.
