The best way to get hold of Fred is just keep calling. Lisa will answer emails but sometimes takes a while (as in a couple of weeks) because they are busy. The collar as you call it is there to help stop the flow of hot gas in case of a blown primer or ruptured shell. It is the front baffle. There is also a rear baffle right at the bolt handle. I would say the baffle is just a touch out of spec but nothing that can't be fixed.
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