Thank you everyone for your input. However I've bit the bullet and changed my Zastava order to one for a Ruger CZ in .416 Rigby at a very good price from HPGS.

It is always cheaper in the long run to buy the factory product and with a bit of gunsmithing the CZ will look and perform as I wish.

Here is a Video of my 16yo son and myself shooting a mates .416 Rigby. They tried to trick him into a flinch by empty loading the rifle for his first shot. They failed.

http://www.youtube.com/watch?v=QZbkL2eBZBA

The smile on his face was priceless.

I also failed by dropping the rifle from my shoulder to reload.