The second one is what I use, barrel up.

Not cross carry, but often single shoulder carry, also with the rifle in the front. Carrying this way I can get a rifle into action jiffy quick.

I often (almost always) have a back pack with me, back slinging doesn't work well.

Also with the rifle in the front (barrel up) you can use the barrel to clear low hanging vegetation away from your hat and face.

Takes a little getting used to, now I wouldn't carry any other way.