According to the information I get from the Blaser web site, the rifle is only made with the primary calibers arranged diagonally, one at the top and one at the lower side, instead of the primary calibers side by side and the secondary caliber on top. Why this should be escapes me.

The Blaser uses a locking system invented by Paul Jaeger which removes all the stress from the action itself and can accomodate anything a bolt action can accomodate. I believe Merkel offers something similar.