Some questions about the Denix MP40

Hi,

I wonder if the Denix MP40 has a hollow barrel or if it's a soid piece. I have seen on some pics that it seems to be solid with a red dot at the front. Maybe this is something that is necessary in US and not in Europe?
I had also liked to know the dimensions of the magazine to see if it's possible to adjust other magazines to go in there.

Are there any other MP40 replicas that are full metal (and in production today) or is the Denix the best one so far?

My Denix has a hollow barrel. timothy