The 30 degree shoulder is supposed to produce the most even pressures, standard deviation etc. I wonder if this is because the 40 shoulder has not been tested as much or it has more to do with the case size and design as most of the current accuracy cases have the 30 degree shoulder.
"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli
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