Yes it is possible to have both on the same plane, infact they have to be on the same plane.

From one photo on a less than stable folding table in a paddock using a 6X scope on a double rifle, I"m not expecting 1/2" groups at 110 yards. However I do expect about an inch group based on my experience with three other blaser double rifles.

The previous group below I shot which is now labelled after it was patched over shows almost perfect horizontal alignment except the shot I pulled to the right on the left barrel. After this group I wound up to get it shooting 40mm high at 100m.

This rifle was bought to hunt with every week for sambar and I'm pretty sure the very experienced owner will have no qualms taking a 200m shot on a sambar with it now.