Yes. You can turn both front and rear end for end, which is useful if you have to accomodate a short scope.
Both of the rifles pictured are, obviously, long action. The scope on the .30-06 is shorter than the scope on the .270. I originally had the scope on the .30-06 and the scope on the .270 mounted the same way. But the shorter scope on the .30-06 was too far forward without enough tude to slide it back for proper eye relief. So I flipped the front base around and remounted the scope which set the scope back some to the same distance from my eye as the scope on the .270.
The overhang on the ejection port make no difference on function. It ejects perfectly. No case contact at all.
The way it was originally mounted. You can see there is no room left on the tube to slide the scope back in the rings. The scope was too far forward and I had to crawl the stock to get a good site picture
Flipping the front base around allowed me to set the scope further back for proper eye relief.