The centerline of the bore 45 degrees would be half way between parallel and a right angle. 45 is an odd angle for a crown, usually the figure I see for competition rifles in 11 degrees, which I presume to actually be 79 degrees. Confusing, isn't it.
To me you cut the barrel off at 90 degrees, so the correct figure should be 11 degress short of that, or 79 degrees. A 45 degree crown is very radical IMHO.
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michael