I don't crimp or worry. I see a setback if there is a mis-feed that jams the bullet tip into the front of the mag. That seldom happens though.
The only down side to crimping is you will work-harden the case lip potentially causing cracks to develop. If you keep your cases trimmed that may never be a problem.
Crimp or don't whatever makes you happy.
Best regards
PS I am loading Varget and the cases are near compressed (not max but full) so it would take a lot to push the bullet back.
I am using Varget also. I am going to try Reloader 15 soon. Anyway here is a page I found with some interesting stuff on it.
http://www.exteriorballistics.com/reloadbasics/gasgunreload.cfm
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