Yes the hole is for gas to escape if the case fails
Thanks for the reply.
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I was figuring it was for that, but wasn't sure.
The barrel marking thing isn't a big deal, but it does look nasty (pics don't show it clearly). More like someone just wacked the barrel with a cheap marking tool and didn't do it right.
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The other markings on the barrel look professional and even.
More importantly, the rifle shoots great and is reliable.