I've had hang fires with the Tula mag small rifle primers and it wasn't any where near -20.
6.5x47 V V N550. Say 15 degrees.
The cci-450 eliminated that problem.
It be interesting to see how the Leupold holds up.. once you pass the 1200 or so round count.
Dave
It'll go on my .338 Lapua eventually. Probably in the next couple months.